weg synchronous alternators naval application 12139384 manual english

8/13/2019 WEG Synchronous Alternators Naval Application 12139384 Manual English

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12139384 Synchronous alternators naval application | 1

Motors I Automation I Energy I Transmission & Distribution I Coatings

Synchronous Alternators

Models: GPW, GSWGPA, GSA

GPF, GSF

Naval application

Installation, Operation and Maintenance Manual


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l 12139384 Synchronous alternators naval application2


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Installation, Operation and Maintenance Manual

Document number: 12139384

Models: GPW, GPA, GPF, GSW, GSA, GSF

Language: English

Revision: 0

August 2012


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Dear Customer,

Thank you for purchasing the WEG alternator. It is a product developed with quality and efficiency

levels that ensure optimal performance.

Electricity plays a role of major importance for the comfort and well-being of humanity. Since the

alternator is responsible for generating this energy, it must be identified and treated as a machine

whose characteristics require certain care, including storage, installation, operation and maintenance.All efforts were made to ensure the information contained herein is accurate regarding the

configurations and use of the alternator.

Thus, we recommend reading this manual carefully before installing, operating and servicing the

alternator in order to ensure a safe and continuous operation of the alternator and guarantee the

personnels and installations safety. If you need any further information, please, contact WEG.

Keep this manual always near the alternator, so it can be referred to whenever necessary.

ATTENTION1. It is imperative to follow the procedures contained in this manual for the warranty to be valid;

2.The procedures for installation, operation and maintenance of the alternator must be carried out byqualified people.

NOTE1. Reproduction of the information contained in this manual, in whole or in part, is permitted provided that

the source is mentioned;

2. If this manual is lost, a copy in electronic format may be obtained at www.weg.netor you may requestWEG a printed copy.

WEG EQUIPAMENTOS ELTRICOS S.A.


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INDEX

1 INTRODUCTION................................................................................................ 91.1 SAFETY WARNINGS IN THE MANUAL .........................................................................................91.2 TERMINOLOGY.............................................................................................................................9

2 GENERAL INSTRUCTIONS ...............................................................................102.1 QUALIFIED PEOPLE....................................................................................................................102.2 SAFETY INSTRUCTIONS ............................................................................................................102.3 STANDARDS...............................................................................................................................102.4 ENVIRONMENT...........................................................................................................................10

2.4.1 Aggressive and/or sea environments ............................................................................102.5 OPERATING CONDITIONS .........................................................................................................10

3 RECEIVING, STORAGE AND HANDLING...........................................................113.1 RECEIVING .................................................................................................................................113.2 STORAGE ...................................................................................................................................11

3.2.1 Storage in sheltered environment .................................................................................11

3.2.2 Storage in unprotected environment.............................................................................113.2.3 Extended storage .........................................................................................................113.2.3.1 Storage location........................................................................................................11

3.2.3.1.1 Storage in sheltered environment...........................................................123.2.3.1.2 Unprotected storage environment..........................................................12

3.2.3.2 Spare parts ............................................................... ................................................123.2.3.3 Space heaters...........................................................................................................123.2.3.4 Insulation resistance..................................................................................................123.2.3.5 Exposed machined surfaces ...................................................... ...............................123.2.3.6 Bearings ....................................................... ............................................................ 123.2.3.7 Terminal box .............................................................. ...............................................133.2.3.8 Inspections and records during storage........................................... ..........................133.2.3.9 Preparation for commissioning ............................................................... ...................13

3.2.3.9.1 Cleaning........................................................... .....................................13

3.2.3.9.2 Bearing lubrication.................................................................................133.2.3.9.3 Checking the insulation resistance ......................................................... 133.2.3.10 Cooling system .......................................................... ...............................................13

3.2.3.10.1 Others ......................................................... ........................................133.2.3.11 Maintenance Plan during storage .................................................................... ..........14

3.3 HANDLING..................................................................................................................................15

4 INSTALLATION ................................................................................................164.1 INSTALLATION LOCATION.........................................................................................................164.2 DIRECTION OF ROTATION .........................................................................................................164.3 DEGREE OF PROTECTION.........................................................................................................164.4 COOLING....................................................................................................................................164.5 INSULATION RESISTANCE.........................................................................................................18

4.5.1 Safety instructions ........................................................................................................184.5.2 General considerations.................................................................................................184.5.3 Measuring the stator winding........................................................................................184.5.4 Measurement on the winding of the rotor, exciter and accessories...............................184.5.5 Minimum insulation resistance ......................................................................................194.5.6 Polarization index..........................................................................................................194.5.7 Conversion of the measured values..............................................................................19

4.6 PROTECTIONS ...........................................................................................................................194.6.1 Thermal protections......................................................................................................19

4.6.1.1 Temperature limits for the windings ............................................................ ...............204.6.1.2 Thermal protections for the bearings ........................................................... ..............204.6.1.3 Alarm and shutdown temperatures................................................................... .........20

4.6.2 Space heater................................................................................................................20

4.6.3 Diode protection...........................................................................................................214.6.4 Protections on the voltage regulator .............................................................................21

4.6.4.1 Protection against underfrequency ............................................................. ...............21

4.7 VOLTAGE REGULATOR..............................................................................................................21


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4.7.1 Maintenance of the short-circuit current....................................................................... 214.8 ELECTRICAL ASPECTS ............................................................................................................. 21

4.8.1 Electrical connections .................................................................................................. 214.8.1.1 Main connection....................................................................................................... 214.8.1.2 Grounding................................................................................................................ 214.8.1.3 Electronic voltage regulator....................................................................................... 224.8.1.4 Terminal identification ..................................................................... .......................... 22

4.8.1.5 Electrical connection of the voltage regulator ............................................................ 224.9 MECHANICAL ASPECTS ........................................................................................................... 224.9.1 Bases and foundations ................................................................................................ 224.9.2 Alignment and leveling ................................................................................................. 224.9.3 Coupling ...................................................................................................................... 23

4.9.3.1 Direct coupling ................................................................ ......................................... 23

5 START-UP .......................................................................................................245.1 PRELIMINARY INSPECTION ...................................................................................................... 245.2 INITIAL OPERATION................................................................................................................... 24

5.2.1 Temperatures .............................................................................................................. 245.2.2 Bearings ...................................................................................................................... 245.2.3 Radiator....................................................................................................................... 25

5.3 SHUTDOWN............................................................................................................................... 255.4 PARALLEL ALTERNATORS........................................................................................................ 25

5.4.1 Parallel to Each Other and/or to the Line...................................................................... 25

6 MAINTENANCE................................................................................................266.1 EMERGENCY GENERATOR GROUPS....................................................................................... 266.2 CLEANING ................................................................................................................................. 266.3 NOISE.........................................................................................................................................266.4 VIBRATION................................................................................................................................. 266.5 BEARINGS ................................................................................................................................. 26

6.5.1 Lubrication................................................................................................................... 266.5.1.1 Type and amount of grease.......................................................... ............................ 266.5.1.2 Instructions for lubrication......................................................................................... 26

6.5.1.3 Procedures for the relubrication of the bearings........................................................ 276.5.1.4 Lubrication of bearings with a drawer and rod for removing the grease.......... ........... 27

6.5.2 Bearing Change........................................................................................................... 276.5.2.1 Bearing replacement ................................................................... ............................. 27

6.6 MAINTENANCE OF THE EXCITER.............................................................................................. 276.6.1 Exciter..........................................................................................................................276.6.2 Diode test .................................................................................................................... 276.6.3 Diode Replacement ..................................................................................................... 286.6.4 Varistor test.................................................................................................................. 286.6.5 Varistor replacement.................................................................................................... 28

6.7 AIR FLOW................................................................................................................................... 286.8 MAINTENANCE OF THE COOLING SYSTEM............................................................................. 28

6.8.1 Maintenance of the radiators........................................................................................ 286.9 ALTERNATOR OUT OF OPERATION.......................................................................................... 296.10 SHAFT GROUNDING DEVICE .................................................................................................... 296.11 COMPLETE CHECKUP .............................................................................................................. 29

7 DISASSEMBLY AND ASSEMBLY OF THE ALTERNATOR...................................307.1 DISASSEMBLY........................................................................................................................... 307.2 ASSEMBLY ................................................................................................................................ 307.3 GENERAL RECOMMENDATIONS .............................................................................................. 307.4 SPARE PARTS ........................................................................................................................... 307.5 MAINTENANCE PLAN................................................................................................................ 31

8 ANOMALIES ....................................................................................................328.1 ELECTRICAL ANOMALIES ......................................................................................................... 328.2 MECHANICAL ANOMALIES ....................................................................................................... 33

9 WARRANTY.....................................................................................................34


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1 INTRODUCTIONThis manual is intended to provide the necessary information on synchronous alternators for naval applications. Alternatorswith special features can be supplied with specific documents (drawings, wiring diagrams, characteristic curves, etc.). Thesedocuments must be carefully studied together with this manual before installing, operating or servicing the alternator.Contact WEG if it is necessary further explanations. All procedures and standards contained in this manual must beobserved in order to ensure the correct operation of the alternator and the safety of the professionals involved in its

operation. Observing these procedures is also important so as to ensure the warranty of the alternator. Thus, werecommend reading this manual thoroughly before installing and operating the alternator. If applicable further information ifnecessary, contact WEG.

ATTENTIONIn case of replacement of the components mentioned in this manual, the manufacturing date must bechecked against the manual review date.

1.1 SAFETY WARNINGS IN THE MANUALIn this manual are used the following safety warnings:

DANGERFailure to observe the procedures recommended in this warning may result in substantial propertydamage, serious injury or death.

ATTENTIONFailure to observe the procedures recommended in this warning may result in property damage.

NOTEThe text with this warning is intended to provide important information for the correct understanding andproper operation of the product.

1.2 TERMINOLOGYG P W 450ALTERNATOR SERIES

G- Synchronous Machines for generator groupsEXCITATION CHARACTERISTICSP- Brushless alternator with auxiliary exciter (PMG)S- Brushless alternator without auxiliary exciterCOOLING SYSTEMA- Open self-ventilatedF- Closed with air-air heat exchangerW- Closed with air-water heat exchangerFRAME - IEC450 to 630


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2 GENERAL INSTRUCTIONSProfessionals who work with electrical installations, either in their assembly, operation or maintenance, must be continuouslyupdated and informed about safety rules and recommendations concerning the service and are advised to observe themstrictly. Before beginning any job, the person in charge must make sure that all the safety measures were properly taken andwarn the operators of the dangers inherent to the task performed. Alternators of this kind, if improperly used or poorlyserviced, or when service by unqualified people, may cause serious personal injury and/or material damage. Therefore, it is

recommended that these services be always performed by qualified people.

2.1 QUALIFIED PEOPLEThe term qualified person means those who, due to theirtraining, experience, education level, knowledge ofapplicable standards, specifications, safety standards,accident prevention and knowledge of the operatingconditions, have been authorized by the people in chargeto execute all necessary services, and who are able torecognize and avoid any possible danger.Those qualified people must also know first aidprocedures and be able to provide that if necessary.It is assumed that the entire commissioning, maintenanceand repair work is made by qualified people only.

2.2 SAFETY INSTRUCTIONSDANGERDuring operation, this equipment hasenergized or rotating parts exposed, whichmay present high voltage or hightemperatures.Thus, the operation with terminal boxesopen, unprotected couplings, or incorrectoperation, disregarding the operatingstandards, may cause serious injury andproperty damage.

Those responsible for the safety in the installation mustensure that: Only qualified people install and operate the equipment; Those people have this manual at hand and other

documents supplied with the alternator, as well asperform the work strictly observing the serviceinstructions, relevant standards and specificdocumentation of the products;

Failure to comply with installation and safety standardsmay void the product warranty.Equipment for fire fighting and first aid signs must beprovided at the workplace in clearly visible and easilyaccessible places.

Also, observe: All technical data regarding applications permitted

(operating conditions, connections and installationenvironment) contained in the catalog, orderdocumentation, operating instructions, manuals andother documents;

The determinations and conditions specific to theinstallation site;

The use of tools and equipment suitable for handlingand transport;

That the protective devices of the individualcomponents be removed shortly before installation.

The individual parts must be stored in an environment freeof vibrations, preventing falls and ensuring that they are

protected against aggressive agents and/or do notendanger the safety of people.

2.3 STANDARDSAlternators are specified, designed, manufactured andtested according to the following standards:

Table 2.1 - Applicable Standards

IEC NBR ISOSpecification 60034-1 5117Dimensions 60072 5432

Tests 60034-4 5052Degree of protection 60034-5 9884Cooling 60034-6 5110Mounting 60034-7 5031

Noise 60034-14 5117 8528

2.4 ENVIRONMENTIn accordance with IEC-60034.1, and ABNT 5117, theambient operating conditions for which the alternatorswere designed are as follows:1. Ambient temperature: 15C to + 40C;2. Altitude (m.a.s.l.): up to 1000 m;3. Environments according to the degree of protection

of the alternator.Special environment conditions are described on thenameplate and specific data sheet of the alternator.

ATTENTIONIn order to use water-cooled alternators attemperatures below 0 C, antifreeze additivesmust be used in the water.

2.4.1 Aggressive and/or sea environmentsAggressive environments comprise: sea environment orwith salinity and/or high humidity, suspended materialsthat can be abrasive, naval applications and environmentswith high ambient temperature variation. The synchronousalternators for naval applications are subject to harshenvironments and are provided with additional protectionagainst corrosion and poor insulation, ensuring, uponrequest, the guarantee of product performance.

2.5 OPERATING CONDITIONSFor the warranty of the product to be valid, the alternatormust operate according to the rated data, followapplicable standards and codes and the informationcontained herein.


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3 RECEIVING, STORAGE AND HANDLING3.1 RECEIVINGAll alternators are tested and are supplied in properoperating condition. The machined surfaces are protectedagainst corrosion. The package must be inspected

immediately upon receipt so as to check whether itsuffered any damage during transport.

ATTENTIONAny damage must be photographed,documented and reported immediately to thecarrier, the insurer and WEG. Failure toobserve this procedure will void the warranty.

ATTENTIONParts supplied in additional packs must be

checked upon receipt.

When lifting the package, observe the proper liftingpoints, the weight stated in the documentation and / oron the nameplate, as well as the capacity and operationof the lifting devices;

Alternators packed in wooden crates must always beraised by their own eyebolts or by a proper forklift, butnever by the wood;

The package can never be overturned. Place it on theground carefully (without impacts) to avoid damage tothe bearings;

Do not remove the grease protections against corrosionfrom the shaft end, coupling discs and flange, or theplugs closing the holes of the terminal box;

These protections must remain in place until themoment of the final assembly. After unpacking, youmust perform a complete visual inspection on thealternator;

The shaft locking system must be removed just beforethe installation and stored in a safe place to be used in afuture transportation of the alternator.

3.2 STORAGEAny damage to the paint or protection against rust of the

machined parts must be corrected.

ATTENTIONDuring storage, the space heaters (ifapplicable) must remain connected to preventwater condensation inside the alternator.

3.2.1 Storage in sheltered environmentIf the alternator is not installed immediately upon receipt, itmust remain in the package and stored in a placeprotected from moisture, steam, rapid temperature

changes, rodents, insects and other agents that maydamage the machine.For the bearings not to be damaged, the alternator mustbe stored in places free from vibration.

3.2.2 Storage in unprotected environmentThe alternator should be stored in a dry place, free fromfloods and vibration.Repair any damage in the package before storing thealternator, which is needed to ensure proper storageconditions.Position the alternator on platforms or foundations thatensure protection against soil moisture and prevent it from

sinking into the ground. It must be ensured free aircirculation underneath the alternator.The cover or canvas used to protect the alternator againstthe weather must not be in contact with its surfaces. Toensure the free air circulation between the alternator andsuch covers, use wooden blocks as spacers.

3.2.3 Extended storageWhen the alternator is stored, the empty spaces inside it,in the bearings, in the terminal box and windings areexposed to air humidity, which can condense.Depending on the type and degree of air pollution, alsoaggressive substances can penetrate these empty

spaces.As a result, after prolonged storage, the resistance of thewinding insulation can fall below the acceptable values.Internal components, such as bearings, may oxidize andthe lubrication capacity of the lubricant may be affected.All these influences increase the risk of damage before theoperation of the alternator.

ATTENTIONTo avoid losing the warranty of the alternator,it must be ensured that all preventivemeasures described in this manual areobserved and recorded.

The instructions outlined below are valid for alternatorswhich are stored for long periods and/or are out ofoperation for a period of two months or more.

3.2.3.1 Storage locationTo ensure the best storage conditions of the alternator forlong periods, the location must comply strictly with thecriteria described below.


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3.2.3.1.1 Storage in sheltered environment The environment must be closed and covered; The local must be protected against moisture, vapors,

aggressive agents, rodents and insects; There cant be the presence of corrosive gases such as

chlorine, sulfur dioxide or acids; The environment must be free of continuous or

intermittent vibration; The environment must feature ventilation system with air

filter; Ambient temperature between 5C and 60C, seeing

that sudden temperature variations must not occur; Air relative humidity 50%.

3.2.3.4 Insulation resistanceDuring the storage period, the stator, rotor and exciterwinding insulation resistance of the alternator must bemeasured and recorded every three months and prior tothe installation of the alternator.Any drop in the value of the insulation resistance must beinvestigated.

3.2.3.5 Exposed machined surfacesAll exposed machined surfaces (for example, shaft end,

flange, coupling disk) are protected at the factory with atemporary protective agent (rust inhibitor).This protective coating must be reapplied at least every 6months or when it is removed and/or damaged.Recommended Products:Name: Dasco Guard 400 TX AZ, Manufacturer: D.A. StuartLtdaName: TARP, Manufacturer: Castrol.

3.2.3.6 BearingsThe rolling bearings are lubricated at the factory for testing.During the storage period, every two months the lockingdevice must be removed from the shaft and the shaft

rotated manually to keep the good conditions of thebearing. After 6 months of storage and before start-up, therolling bearings must be relubricated. If the alternator iskept in storage for over two years, the rolling bearingsmust be cleaned, inspected and relubricated so as toensure their integrity.

ATTENTIONIf you cannot turn the shaft of the alternator,as recommended, check the conditions of therolling bearing before the commissioning ofthe alternator.


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3.2.3.7 Terminal boxWhen the alternator winding insulation resistance ismeasured, the main terminal box and the other terminalboxes must be inspected, considering especially thefollowing aspects: The inside must be dry, clean and free of dust

accumulation;

The contacts cannot present corrosion; The seals must be in proper conditions; The cable inputs must be properly sealed according to

the machine degree of protection.If applicable of these items is not correct, the partsmust be cleaned or replaced.3.2.3.8 Inspections and records during storageStored alternators must be periodically inspected andinspection records must be filed.The following points must be inspected:1. Physical damages;2. Cleanliness;

3. Signs of water condensation;4. Conditions of the protective coating of the machined

parts;5. Paint conditions;6. Signs of aggressive agents;7. Satisfactory operation of space heaters (if applicable). It

is recommended that a signaling system or alarm beinstalled in the location in order to detect powerinterruption in the space heaters;

8. It is recommended to record the ambient temperatureand air relative humidity around the machine, windingtemperature, insulation resistance and polarizationindex;

9. The storage location must also be inspected so as to

ensure its compliance with the criteria described in theitem Storage ocation.

3.2.3.9 Preparation for commissioning3.2.3.9.1 Cleaning Generator inner and outer parts must be free of oil,

water, dust, and dirt. Remove the rust inhibitor from the exposed surfaces

with a cloth damped in a petroleum-based solvent; Make sure the bearings and cavities used for lubrication

are free of dirt and the cavity plugs are correctly sealedand tightened.

3.2.3.9.2 Bearing lubricationUse the specified lubricant to lubricate the bearing.The information on bearings and lubricants, as well as theprocedure for lubrication, are described in item BearingMaintenanceof this manual.

3.2.3.9.3 Checking the insulation resistanceATTENTIONBefore operating the alternator, the insulationresistance must be measured according tothe item Insulation resistanceof thismanual.

3.2.3.10 Cooling systemFor water-cooled alternators, if they remain out ofoperation for a long time, it must be ensured the waterruns freely in the alternator cooling circuit before starting it

again.

3.2.3.10.1OthersFollow the other procedures described in the item ommissioningin this manual before performing thestart-up of the alternator.


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3.2.3.11 Maintenance Plan during storageDuring the storage period, the alternator maintenance must be performed and recorded according to the plan described inTable 3.1.

Table 3.1 - Storage plan

MonthlyEvery two

months

Every six

months

Every

two years

Beforecommission

ing

NOTE!

Storage locationInspect the cleaning conditions X XInspect the humidity and temperatureconditions

XCheck signals of aggressive agents XMeasure vibration level XPackageInspect physical damage XInspect relative humidity inside XChange the dehumidifier in the package(if applicable)

X Whenever necessarySpace heaters (if applicable)Check the operating conditions XComplete alternatorPerform external cleaning X XPerform internal cleaning XCheck the paint conditions XCheck the oxidation inhibitor on exposedparts

X Replace the inhibitor, ifnecessary

WindingsMeasure the insulation resistance X XMeasure polarization index X XTerminal boxes and ground terminalsClean the inside of the terminal boxes X XInspect the seals X X

Tighten the terminal connections X in accordance withtightening torqueinformed in this manual

BearingsTurn the shaft of the alternator XRelubricate the bearing X XDisassemble, clean, inspect andrelubricate the bearing

X X If the storage period islonger than 2 years


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3.3 HANDLINGProper handling

Figure 3.1 - Proper handling

Improper handling

Figure 3.2 - Improper handling

The alternator was designed with eyebolts for lifting. These eyebolts are designed to lift only the alternator; additionalloads are not permitted;

Cables and lifting devices must be appropriate.

NOTES Observe the weight informed. Do not lift and do not put the alternator on the ground suddenly to avoid damage to the bearings. To lift the alternator, use only the existing eyebolts. If you necessary, use a beam to protect parts of the

alternator. The eyebolts on the covers, bearings, terminal box, etc., are intended to handle these components only. Never use the shaft to lift the alternator. To move the alternator, the shaft must be locked with the locking device supplied with the alternator.

ATTENTIONSteel cables, clevises and lifting equipment must be appropriate and able to withstand the weight of the

alternator so as to avoid accidents, damage to the alternator and injuries.


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4 INSTALLATION4.1 INSTALLATION LOCATIONThe alternator must be installed in easily accessiblelocations, which allow the execution of periodicinspections, local maintenance and, if necessary, theremoval of the alternator for external services.The following environmental features must be provided: The alternator must receive fresh and clean air and the

location must allow the easy exhaust of the air from theoperating environment, preventing air recirculation;

The alternator must not aspire the exhaust from thediesel engine, because soot is an electric conductorand shortens the life of the insulation, which can causethe burning of the alternator;

The installation of other equipment or walls must nothinder or obstruct the ventilation of the alternator;

There must be space enough around and above thealternator for servicing or handling it;

The environment must comply with the alternatordegree of protection.

NOTEFor alternators with single bearing, the shaftlocking device (used to protect the rotor/statoragainst damage during transportation) mustonly be removed right before coupling it to thedriving machine.

4.2 DIRECTION OF ROTATIONAlternators can operate in both directions of rotation.The phase sequence is set clockwise rotation(facing theshaft end of the alternator - drive end).The alternator terminals are marked in such a way thatthe sequence of the terminals U, V and W matches thephase sequence R, S and T or L1, L2 and L3, when therotation is clockwise.In the case of alternators that need to operate in thecounterclockwise direction, the phase sequence mustbe changed (if required). It is recommended to check thedirection of rotation and phase sequence required beforethe start-up of the alternator.

ATTENTIONWrong phase sequence may cause damageto the equipment supplied by the alternator. Inthe case of operation in parallel with otheralternators and/or network, they must havethe same phase sequence.

4.3 DEGREE OF PROTECTIONIt is essential to observe the degree of protection of thealternator in relation to the installation environment so asto ensure the proper performance and long life of theequipment.

4.4 COOLINGOpen alternators

Figure 4.1 - Cooling - model GPA

Open alternators are cooled by the internal fan.

Closed alternators

Figure 4.2 - Cooling - model GPW

Figure 4.3 - Cooling - model GPF

Closed alternators are cooled through the air-water heatexchanger (model GPW) or air-air heat exchanger (modelGPF).The water supply system for alternators GPW must beinstalled by the user, meeting the characteristics of theheat exchanger nameplate.

ATTENTION In order to ensure the proper operation and

prevent the overheating of the alternator,the data of the cooling system informed onthe nameplate must be strictly observed;

Water or air inputs and outputs must not beblocked in order to prevent overheating andeven the burning of the alternator.


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Characteristics of the cooling waterAlways use treated industrial water with the followingcharacteristics: ph: 7.0 to 8; Chlorides: < 50 ppm; Iron content: < 0.3 ppm

Hardness: < 150 ppm Alkalinity: < 200 ppm Conductivity: < 400S/cm; Sulfate: < 50 ppm; Nitrate: < 10 ppm; Ammonia: < 10 ppm; Maximum size of charged particles in the water: 0.1mm:

ATTENTIONFor cooling the alternator, a closed-circuitwater system must be used, and the watermust meet the characteristics specified in item

above.

Add additives to the cooling water in properquantities for protection against corrosion andseaweed growth. The type and amount ofadditives used must be specified by themanufacturer of these additives and inaccordance with the environmental conditionswhere the alternator is installed.

In order to use the alternator in environmentswith temperatures below 0C, glycol-basedantifreeze additives must be added to thecooling water.

Heat exchangers for applications with sea waterATTENTIONIn the case of heat exchangers for applicationswith sea water, the materials in contact withwater (pipes and mirrors) must be resistant to

corrosion.Furthermore, the heat exchangers may befitted with sacrificial anodes (for example, zincor magnesium), as shown in Figure 4.4. In thisapplication, the anodes are corroded duringoperation, protecting the heads of theexchanger.In order to maintain the integrity of the heatexchanger heads, these anodes must bereplaced periodically according to thecorrosion rate appears presented.

Figure 4.4 - Heat exchanger with sacrificial anodes

NOTEThe type, quantity and position of thesacrificial anodes may vary from application toapplication.

Cooling water temperatureAlternators cooled by air-water heat exchangers are ableto operate with a temperature of the cooling water in theinput as specified in the project and informed on the heatexchanger nameplate.

Protective devicesThe protective devices of the cooling system must bemonitored periodically as described in the item

Protectionsof this manual.

Sacrificial anodes


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4.5 INSULATION RESISTANCE4.5.1 Safety instructions

DANGERBefore measuring the insulation resistance,the alternator must be stopped anddisconnected from the charge and the voltageregulator disconnected.The winding being tested must be connectedto the frame and to the ground for a perioduntil removing the residual electrostaticcharge.Failure to observe these procedures mayresult in personal injury.

4.5.2 General considerationsWhen the alternator is not immediately put into operation,it must be protected against moisture, high temperatureand dirt, thus avoiding damages to the insulation.The insulation resistance of the windings is measuredbefore commissioning.If the environment is too humid, it is necessary to check itperiodically during storage. It is difficult to determine rulesfor the real value of the insulation resistance of amachine, since it varies with environmental conditions(temperature, humidity), conditions of machine cleaning(dust, oil, grease, dirt) and quality and conditions theinsulating material used.The assessment of the periodic monitoring records isuseful to conclude whether the alternator is able tooperate.

NOTEThe insulation resistance must be measuredusing a MEGOHMMETER.

4.5.3 Measuring the stator windingThe test voltage for the stator windings of the alternator

must be as per Table 4.1in accordance with standard

IEEE43.

Table 4.1 Voltage for measuring the insulation resistance

Rated voltage of thewinding (V)

Insulation resistance testContinuous voltage (V)

< 1000 500

1000 - 2500 500 -1000

2501 - 5000 1000 - 2500

5001 - 12000 2500 - 5000

> 12000 5000 - 10000

Before making the measurement on the stator winding,check the following: If all cables are disconnected from the charge; If the voltage regulator is disconnected. If the alternator frame and the windings not measured

are grounded; If the temperature of the winding was measured; If all temperature sensors are grounded.

The measurement of the insulation resistance of thestator windings must be done in the main terminal box.The meter (megohmmeter) must be connected betweenthe alternator frame and the winding. The frame must begrounded and the three phases of the stator windingremain connected to the neuter point, as shown below:

Figure 4.5 - Measurement on the three phases

When possible, each phase must be isolated and testedseparately. The separate test allows a comparisonbetween the phases. When a phase is tested, the othertwo phases must be grounded on the same ground ofthe frame, as shown below.

Figure 4.6 - Measurement in separate phases

4.5.4 Measurement on the winding of therotor, exciter and accessoriesMeasurement on the rotor winding: Disconnect the cables of the rotor from the diode

cluster; Connect the insulation resistance meter

(megohmmeter) between the rotor winding and theshaft of the alternator. The measurement currentcannot pass through the bearings.

Measurement of the stator winding of the main exciter. Disconnect the power cables from the exciter; Connect the insulation resistance meter

(megohmmeter) between the exciter stator winding(terminals F+ and F-) and the alternator frame.

Measurement on the rotor winding of the main exciter. Disconnect the cables of the exciter rotor from the

diode cluster; Connect the insulation resistance meter

(megohmmeter) between the rotor winding and theshaft of the alternator. The measurement currentcannot pass through the bearings.

Measurement of the stator winding of the auxiliary exciter(PMG) - alternators model GP --_: Disconnect the cables that connect the auxiliary exciter

to the voltage regulator; Connect the insulation resistance meter

(megohmmeter) between the stator winding of theauxiliary exciter and the alternator frame.

M

M


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ATTENTIONThe test voltage for the rotor, main exciter,auxiliary exciter and space heaters must be500Vdc and 100Vdc for other accessories.It is not recommended to measure the

insulation resistance of thermal protectors.

On machines that are already in operation, higher valuesof insulation resistance can be measured, compared tothe initial values of commissioning.The comparison with values obtained in previous tests onthe same machine, in similar load, temperature andhumidity conditions is as a better indication of theinsulation conditions than the value obtained in a singletest, seeing that any sudden reduction is consideredsuspicious.

Table 4.2 - Referential limits of the insulation resistance in electricalmachines

Insulation resistance value Insulation assessment2Mor lower Dangerous

< 50M Bad

50...100M Regular

100...500M Good

500...1000M Very Good

> 1000M Excellent

4.5.5 Minimum insulation resistance If the measured insulation resistance is below 100 M

at 40 C, the windings must be carefully inspectedand cleaned or, if necessary, dried according to thefollowing procedure before the machine goes into

operation: Disassemble the alternator by removing the rotor and

bearings; Place the components that have the winding with low

insulation resistance in an industrial oven and heat it upto a temperature of 130C and keep this temperaturefor at least 08 hours.

Check if the insulation resistance achieved is within theacceptable values, in accordance withTable 4.2,otherwise contact WEG.

4.5.6 Polarization indexThe polarization index (I.P.) is typically defined by the ratio

between the measured insulation resistance in 10minutes and the insulation resistance measured in 1minute at relatively constant temperature. By means ofthe polarization index, the insulation conditions of thealternator can be evaluated according toTable 4.3.

Table 4.3 - Polarization index (ratio between 10 and 1 minute)

Polarization index Insulation assessment

1 or lower Dangerous

< 1.5 Bad

1.5 to 2.0 Regular

2.0 to 3.0 Good

3.0 to 4.0 Very Good

> 4.0 Excellent

DANGERImmediately after measuring the insulationresistance, ground the winding to avoidaccidents.

4.5.7 Conversion of the measured valuesIf the test is done at a different temperature, it isnecessary to correct the reading for 40C by using acurve for the variation of the insulation resistanceconsidering the temperature, determined with themachine itself. If this curve is not available, theapproximate correction provided by the curve of Figure4.7can be used, according to NBR 5383 / IEEE43.

Figure 4.7 - Coefficient of insulation resistance variation according totemperature

4.6 PROTECTIONS4.6.1 Thermal protectionsThe alternators have protection devices againsttemperature rise, installed on the main stator coils andbearings, as follows:

Insulationresista

ncevariationcoefficientKt40C

Winding temperature CR40C= Rt x Kt40C

In order to convert the insulation resistancemeasured (Rt) to 40C, multiply it by the

temperature coefficient (Kt)


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Thermoresistance (RTD) - It is a calibrated resistanceelement.Its operation is based on the principle that theelectrical resistance of a metallic conductor varies linearlywith temperature. The terminals of the detector must beconnected to a control panel which includes atemperature meter.

NOTEThe RTD-type thermoresistance allowsmonitoring the absolute temperature. Withthis information, the relay can perform thereading of the temperature, as well as theparameterization for alarm and shutdownaccording to the preset temperatures.

The following formula is used to convert into temperaturethe value of the ohmic resistance measured by thethermoresistance type Pt 100.

Where: = ohmic resistance measured on the PT-100

The protective devices, when requested, are listed in thespecific wiring diagram of each alternator. Failure in usingthese devices is the users sole responsibility, and mayresult in loss of warranty in case of damage.

4.6.1.1 Temperature limits for the windingsThe temperature of the hottest spot of the winding mustbe kept below the limit of insulation thermal class. Thetotal temperature is composed of the ambienttemperature with the temperature rise (T), plus thedifference between the average temperature of thewinding and the hottest spot of the winding. The ambienttemperature is typically at most 40C. Above this value,the working conditions are considered special.Table 4.4shows the numerical values and thecomposition of the acceptable temperature of the hottestspot of the winding.

Table 4.4 - Insulation class

Insulation class F H

Ambient temperature C 40 40

T = temperature rise (resistance method) C 105 125Difference between the hottest spot and theaverage temperature

C 10 15

Total: temperature of the hottest point C 155 180

ATTENTIONIf the alternator operates with windingtemperatures above the limits of the thermalclass, the life of the insulation and hence ofthe alternator is reduced substantially, or itmay even burn.

4.6.1.2 Thermal protections for the bearingsThe temperature sensors installed on the bearings areintended to protect them from damage due to operationwith over temperature.

4.6.1.3 Alarm and shutdown temperaturesThe alarm and shutdown temperatures must be set aslow as possible. These temperatures can be determinedbased on the results of tests or through the alternatoroperating temperature.The alarm temperature can be set at 10C above thealternator operating temperature at full load consideringthe highest ambient temperature of the local. Thetemperature values set to shutdown must not exceed themaximum acceptable temperatures as listed inTable 4.5andTable 4.6.

Table 4.5 - Stator maximum temperature

STATOR WINDINGMaximum temperature settings of

protections (C)

Class

of InsulationAlarm Shutdown

F 140 155H 155 180

Table 4.6 - Bearing maximum temperature

BEARINGSMaximum temperature settings of protections (C)

Alarm Shutdown110 120

ATTENTIONThe temperature values for alarm andshutdown can be set based on experience,but must not exceed the maximum valuesindicated inTable 4.5andTable 4.6.

4.6.2 Space heaterThe space heater used to prevent condensation of waterduring long periods without operation must beprogrammed so as to be always energized after theshutdown of the alternator and to be de-energized beforethe alternator goes into operation.The dimensional drawing and a specific nameplate on the

alternator indicate the supply voltage and the power ofthe installed space heaters.

ATTENTIONIf the space heaters remain energized whilethe machine is in operation, the winding maybe damaged.

Formula: - 100 = C0,386


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4.6.3 Diode protectionThe diodes have varistors installed on the rotating diodebridge of the main exciter, protection against overvoltageand/or voltage surge.In case of failure of these components, they must bereplaced.

4.6.4 Protections on the voltage regulator4.6.4.1 Protection against underfrequencyIn order to put the alternator into operation, theprotection against underfrequency of the voltageregulator must be set at 90% of the rated frequency (itcomes set from the factory) or the voltage regulator mustremain turned off until the group reaches the ratedspeed, avoiding excitation overcurrents of the alternator.

NOTEThe other protections of the voltage regulator

are described in its specific manual.

Application 60HZ

Application 50HZ(V)

Un

U f

45 (Hz)50

4.7 VOLTAGE REGULATORThe electronic voltage regulator is designed to keep thevoltage of the alternator constant regardless the load.It may be assembled in the terminal box of the alternatoror on the control panel.

ATTENTIONCheck, in the Manual of the voltageregulator, the terminals and wiring diagram andthe setting parameters.A wrong connection may cause the burning ofthe regulator and/or the alternator windings.Defects caused by this reason are not covered

by the warranty.

For further technical details on operation, functions,connections, settings, anomalies, etc., refer to thevoltage regulator specific manual.4.7.1 Maintenance of the short-circuit currentWEG alternators for naval applications are manufactured

with the auxiliary exciter mounted in its back, which isresponsible for feeding the power circuit of the voltageregulator and keeping the short-circuit current of thealternator.

NOTES1.Because the alternator maintains high SCC,

an overcurrent relay must be installed so asto open the main breaker in no more than20s, under penalty of burning the alternator.

2.In order to keep the short circuit currentabove 3.0 x In, contact WEG.

4.8 ELECTRICAL ASPECTS4.8.1 Electrical connectionsThe alternator electrical connections are responsibility ofthe end user and must be carried out by qualified people.The connection diagrams are provided along with thetechnical documentation of the alternator.

4.8.1.1 Main connectionThe main cable connections must be done observing the

tightening torque according toTable 4.7for fixing thecables.

Table 4.7 - Tightening torque of the terminal screws for fixing the maincables

Thread DiameterTightening torque

(Nm)

M5 5-6

M8 20-25

M10 39-49

M12 64-84

M16 165-206

Make sure the section and insulation of theconnecting cables are suitable for the alternatorcurrent and voltage;

Before making the electrical connections betweenthe alternator and the load or power line, it isnecessary to check carefully the winding insulationresistance, according toTable 4.2.

4.8.1.2 GroundingThe alternators must always be grounded with a cable ofproper section by using the terminal located in one of itsfeet.

(V)

Un

U/f

6054 (Hz)


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4.8.1.3 Electronic voltage regulatorThe electronic regulator comes from the factoryelectrically connected and set for the alternator ratedfrequency and voltage.In order to change the connections or settings, refer tothe voltage regulator manual.

ATTENTIONIn order to change the operating frequency ofthe voltage regulator, refer to its manual.

4.8.1.4 Terminal identificationThe identification of the alternator and accessoryterminals is provided in the specific wiring diagram ofeach alternator.

4.8.1.5 Electrical connection of the voltageregulator In order to perform correctly the electrical connections

of the alternator to the voltage regulator, refer to themanual of the voltage regulator.

The model of the used voltage regulator depends onthe characteristics of the alternator and the desiredapplication. Therefore, the electrical connections to thealternator and the identification of the terminals maydiffer from one model to another.

The manual of the voltage regulator is provided withthe alternator.

4.9 MECHANICAL ASPECTS4.9.1 Bases and foundations The dimensioning of the bases must be performed so

as to confer rigidity to the structure, avoidingamplification of the vibration levels of the set. The basemust have a flat surface against the feet of thealternator in order to prevent deformations on theframe.

The base must always be leveled in relation to theground (floor). The leveling is obtained by placingshims between the base and the floor.

The shims for leveling must cover at least 80% of thesurface area of contact with the feet.

The material of the leveling shims must provide thesame rigidity of the basis.

4.9.2 Alignment and levelingThe alternator must be perfectly aligned with the drivingmachine, especially in cases of direct coupling

ATTENTIONAn incorrect alignment may damage the

bearings, cause vibration and break the shaft.

The alternator must be correctly aligned with the driving,especially in cases of direct coupling.The alignment must be done according to therecommendations of the coupling manufacturer.It is necessary to make the parallel and angular alignmentof the alternator, as shown in Figure 4.8and Figure 4.9.

Parallel misalignment Radial measurement

Figure 4.8 - Parallel alignment

Figure 4.8shows the parallel misalignment of the twoshaft ends and the practical way to measure it by usingsuitable dial gauges.The measurement is made in four points at 90, with thetwo half-couplings rotating together so as to eliminate the

effects of surface irregularities on the dial gauge contactsurface. Choosing the upper vertical point 0, half thedifference of the dial gauge measurement in points 0and 180 represents the vertical coaxial error. This mustbe properly corrected by adding or removing shims. Halfthe difference of the dial gauge measurement in points90 and 270 represents the horizontal coaxial error.Thus we get an indication of how much it is necessary toraise or lower the alternator or move it to the right or lefton the drive end in order to eliminate the coaxial error.Half the difference of the dial gauge measurement in a fullrevolution represents the maximum eccentricity.The maximum acceptable eccentricity for rigid orsemi-flexible coupling is 0.03 mm.Where flexible couplings are used, higher values thanthose aforementioned are acceptable, but they must notexceed the value given by the coupling manufacturer. It isrecommended to keep a safety margin in these values.

Angular misalignment Axial measurement

Figure 4.9 - Angular alignment

Figure 4.9shows the angular misalignment and thepractical way of measuring itThe measurement is made in four points at 90, with thetwo half-couplings rotating together so as to eliminate theeffects of surface irregularities on the dial gauge contactsurface. Choosing the upper vertical point 0, half thedifference of the dial gauge measurement in points 0and 180 represents the vertical misalignment. This mustbe properly corrected by adding or removing shims.Half the difference of the dial gauge measurement inpoints 90 and 270 represents the horizontalmisalignment. This must be properly corrected with the

lateral/angular movements of the alternator.Half the maximum difference of the dial gaugemeasurement in a full revolution represents the maximumangular misalignment.


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The maximum acceptable misalignment for rigid orsemi-flexible coupling is 0.03 mmWhere flexible couplings are used, higher values thanthose aforementioned are acceptable, but they must notexceed the value given by the coupling manufacturer.It is recommended to keep a safety margin for thesevalues.In alignment/leveling, it is important to consider the effectof temperature of the alternator and of the drivingmachine. Different levels of expansion of the coupledmachines can change the alignment/leveling during theoperation.

4.9.3 Coupling4.9.3.1 Direct couplingThe direct coupling must always be preferred, due tolower cost, fewer space requirements, no slip (belt) andgreater security against accidents. In the case of

transmission with speed ratio, it is also common the useof direct coupling through gearboxes.

ATTENTIONCarefully align the shaft ends, using a flexiblecoupling whenever possible, leaving aminimum clearance of 3 mm between thecouplings.

Figure 4.10 - Axial clearance

NOTEThe user is responsible for the installation of thealternator.WEG is not responsible for damages to thealternator, associated equipment and installationwhich occurred due to: Excessive transmitted vibrations; Poor installations;

Alignment failures; Improper storage conditions; Noncompliance with the instructions before

start-up; Incorrect electrical connections.

Axial clearance


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5 START-UP The alternator leaves the factory with a lock on the shaft for better safety in transportation. Before starting it, this lock

must be removed. The connection of the terminals complies with the rated characteristics of the alternator plate. In order to perform the adjustment of voltage and frequency, refer to the voltage regulator manual.

5.1 PRELIMINARY INSPECTIONBefore the first start-up or after a long time out ofoperation, check:1. If the alternator is clean and if the packaging materials

and protective elements were removed;2. If the connection parts of the coupling are in perfect

conditions and well greased and tightened wherenecessary;

3. If the alternator is aligned;4. If the bearings are properly lubricated and in working

condition;5. If the cables of the accessories are connected;6. If the windings insulation resistance has the

prescribed value;7. If all objects, such as tools, measuring instrumentsand alignment devices, were removed from thealternator operation place;

8. If the alternator is properly fixed;9. If the electrical connections are in accordance with

the wiring diagram of the alternator;10. If the voltage regulator is properly connected and

adjusted according to its installation manual;11. If the conductors of the line are properly connected to

the main terminals so as to prevent a short circuit ordisconnection;

12. If the alternator is properly grounded;13. If the cooling system is working.

14. If the air inputs and outputs are clear;15. If the water inputs and outputs are clear (alternatorswith air-water heat exchanger);

16. Manually rotate the assembly in order to ascertainwhether there is no interference in the air gap. Afterthe alternator is driven with no load, it must rotatesmoothly without strange noises;

5.2 INITIAL OPERATIONIn addition to following the safety instructions given in item2.2of this manual, in order to perform the first start-up ofthe alternator, the following procedure must be adopted:a) Make sure that the alternator terminals are

disconnected from the load by removing the fuses onthe panel or placing the circuit breaker in the "off"position;

b) Turn off the space heaters of the alternator, beforestarting it;

c) Disconnect the voltage regulator.

ATTENTIONThe function of the U/F regulator is set at thefactory; however, as additional safety, it isrecommended to disconnect the voltageregulator.

d) Rotate the assembly and check for strange noises;

e) Drive the alternator up to the rated speed and verifynoises and vibration, and check all protective devices;

After following the procedures described above andsolving any problems that may have occurred (seeanomalies/solutions), turn off the set.f) With the alternator completely stopped, connect the

voltage regulator, activate the set and make thenecessary adjustments. The manual of the voltageregulator describes the procedures for the availablesettings (stability, voltage, U/F).

g) Close the main circuit breaker and apply load andmonitor the alternator current, making sure that it iswithin the specification.

h) Check the vibration and temperature levels of the setand monitor the measuring instruments (current,voltage and frequency). If there is significant variation

in the vibration of the set between the initial conditionand after the temperature stabilizes, it is necessary toreassess the alignment/leveling of the set.

ATTENTIONAll measuring and control instruments mustbe under constant observation so that anychanges in operation can be detected andremedied.

5.2.1 TemperaturesThe temperatures of the bearings, stator winding and

cooling water (if applicable) must be monitored while thealternator is operation. These temperatures must stabilizewithin 4 to 8 hours of operation.The temperature of the stator winding depends on theload; therefore, the supplied load must also be monitoredduring the operation of the alternator.

5.2.2 BearingsThe start-up of the system, and the first hours of operationmust be continuously monitored. Watch for vibration or abnormal noise. If the bearing

does not work in a silent and smooth way, thealternator must be stopped immediately, the cause

found and corrected. The alternator must operate for several hours until the

bearing temperature stabilizes within the limitsmentioned in this manual.

If the bearing temperature rises, the alternator must bestopped in order to check the bearings andtemperature sensors.

After reaching the bearing working temperature, checkfor leaks through the plugs, gaskets or shaft end.


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5.2.3 RadiatorIn alternators with air-water heat exchanger, the followingprocedures must be followed during the first start-up: Control the temperature in the input and output of the

radiator and, if necessary, correct the water flow; Adjust the water pressure to just overcome the

resistance in the pipes and radiator; To control the operation of the alternator, it isrecommended to record the air and water temperaturesin the input and output of the radiator at certainintervals;

Recording or signaling (buzzer, light bulbs) instrumentscan be installed in certain places.

Verification of the radiator performance In order to control the operation, it is recommended

that the water and air temperature in the input andoutput of the radiator be measured and recordedperiodically.

The performance of the radiator is expressed by thedifference in temperatures between cold water and coldair during normal operation. This difference must bechecked periodically. If it is observed an increase in thisdifference after a long period of normal operation, it maybe a sign that the radiator must be cleaned.

A reduction in the performance or damage to theradiator can also occur due to accumulation of air insideit. In this case, bleeding the air from the radiator andwater pipes can correct the problem.

The pressure difference on the water side can beconsidered an indicator of the need for cleaning theradiator.

It is also recommended to measure and record the valuesof the water pressure difference before and after the

radiator. Periodically, the new values must be comparedto the original value, and an increase in the pressuredifference indicates the need for cleaning the radiator.

5.3 SHUTDOWNa) Before stopping the alternator, open the main circuit

breaker to disconnect the load;b) Reduce the speed of the alternator until it comes to a

full stop;c) In alternators with air-water heat exchanger, after the

alternator stops completely, close the valve of thecooling water.

d) Turn on the space heaters if the alternator remainsstopped for a long period.

DANGEREven after de-excitation, there is still voltage atthe terminals of the machine. Therefore, onlyafter the full stop of the equipment, it isallowed to perform any work.The noncompliance with the procedure aboveimplies risk of death.

5.4 PARALLEL ALTERNATORS5.4.1 Parallel to Each Other and/or to the LineMinimum requirements for operation of the alternators inparallel, not including the driving machine control:1. The alternator must have the same operating voltage

of the alternator or another network;2. The voltage regulator must permit the operation of the

alternator in parallel;3. Add a parallel CT to one of the phases of the

alternator and make the electrical connectionaccording to the manual of the voltage regulator.

4. Have a panel suitable for protection and operation ofthe alternator in parallel.

5. The synchronization and setting of the real powermust be imposed by the speed control of the primarymachine.

In case high neutral currents appear, use a ground coil oropen the neutral connection of one of the alternators. Thishappens especially when the alternators are not equal orwhen they feed loads with high harmonic content.

ATTENTIONThis type of installation must be performed byqualified technical staff.For transient operations in parallel (e.g.,loading ramp) in which the alternator willoperate in the single mode after a period inparallel, the parallel CT must be short-circuited, since it is unnecessary for thisoperation.


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6 MAINTENANCEMaintenance procedures must be performed so as to ensure the proper performance of the equipment. The frequency ofthe inspections will largely depend on the application local conditions and operating conditions.Failure to comply with one of the items listed below may lead to the reduction of the alternator life, unnecessary stops and/ordamage to the facilities.

6.1 EMERGENCY GENERATORGROUPS

The alternators used in emergency generator groupsmust, according to the humidity level of the site, receiveload 2 to 3 hours each month.

6.2 CLEANINGThe frame, multi-leaf dampers, grids and fan covers mustbe kept clean, without accumulation of oil or dust on theoutside to facilitate the heat exchange with theenvironment.

Also, the inside of the alternators must be kept clean andfree of dust, debris and oil. In order to clean them,brushes or clean cotton rags must be used. If the dust isnot abrasive, an air gun must be used to blow the dirt offfrom the fan cover and eliminate all the accumulation ofdust contained on the fan blades and frame.The debris impregnated with oil or humidity can becleaned with cloth moistened in a suitable solvent.The terminals in the terminal box must be clean, free ofrust, in perfect mechanical condition and without depositsof grease or verdigris.

6.3 NOISEThe noise must be observed at regular intervals of 1 to 4months. In case of anomalies, the alternator must bestopped and the causes must be investigated andcorrected.

6.4 VIBRATIONMaximum vibration level for the alternator under load:

20mm/s(RMS).Confirm standard ISO-8528

6.5 BEARINGSThe temperature control on the bearings is also part of

routine maintenance of the alternators. The temperaturerise must not exceed 60C, measured in the outer ring ofthe bearing.The temperature can be controlled permanently withthermometers placed outside the bearing, or throughthermoresistances.The alarm and shutdown temperatures for the bearingscan be adjusted respectively for 110C and 120C.

6.5.1 LubricationThe bearings must be relubricated annually or accordingto the lubrication intervals reported on the nameplate ofthe bearings fixed on the alternator and to the technical

documentation, prevailing whichever occurs first.

6.5.1.1 Type and amount of greaseThe relubrication of the bearings must always be madewith the original grease, specified on the bearingnameplate and the documentation of the alternator.

ATTENTION1.WEG does not recommend the use of

grease different from the alternator originalgrease.

2.When the bearing is opened, inject the newgrease through the grease nipple to expelthe old grease found in the grease input

tube and insert the new grease in thebearing, in the inner ring and outer ring,filling three quarters of the empty spaces.

3.Never clean the roller with cotton-basedcloths, because they leave some lint assolid particles.

4.It is important to perform a properlubrication, that is, to apply the greasecorrectly and in a suitable quantity, becauseboth poor lubrication and excessivelubrication adversely affect the bearing.

5.Excessive lubrication causes thetemperature to rise due to the greatresistance it offers to the spinning of

rotating parts and, mainly, due to thestirring of the grease, which will eventuallycompletely lose its lubricant characteristics.

NOTEWEG is not responsible for the change ofgrease or for any damages arising from theexchange.

6.5.1.2 Instructions for lubricationThe lubrication system is designed in such a way that

during the relubrication of the bearings, all the old greaseis removed from the rolling bearings tracks and expelledthrough a drain which enables the exit, but prevents theentering of dust or other harmful contaminants.This drain also prevents damage to the bearings by thewell-known problem of excessive lubrication.It is advisable to perform the lubrication with the alternatorin operation, so as to ensure the renewal of grease in thebearing housing.If this is not possible due to the presence of rotating partsnear the nipple (pulleys, etc.), which can put the operatorin danger, proceed as follows: With the alternator stopped, inject approximately half

the total amount of grease recommended and operate

the alternator for approximately 1 minute at full speed; Stop the alternator and inject the remaining grease. The

injection of all grease with the alternator stopped maycause penetration of the lubricant into the alternator.


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ATTENTIONIt is important to clean the grease nipples priorto lubrication so as to prevent foreign materialsfrom being dragged into the bearing.

NOTEThe data of the rolling bearings, quantity andtype of grease and lubrication intervals areinformed in a nameplate fixed on thealternator. Check this information beforeperforming the lubrication.

The lubrication intervals informed on the plate considera working temperature of the bearing of 70C.

Based on the operating temperature ranges listedbelow, apply the following correction factors for thelubrication of bearings:

Operating temperature below 60C: 1.59. Operating temperature 70C to 80C: 0.63. Operating temperature 80C to 90C: 0.40. Operating temperature 90C to 100C: 0.25 Operating temperature 100C to 110C: 0.16.

6.5.1.3 Procedures for the relubrication of thebearings1.Remove the cover of the drain;2.Clean with a cotton cloth around the hole of the grease

nipple;3.With the alternator running, inject grease until new

grease begins to flow from the drain or until the amount

of grease informed on the bearing nameplate have beeninjected;4.Run the alternator for time enough to eliminate the

excess of grease through the drain;5.Inspect the bearing temperature to make sure that there

was no significant change;6.Put the cover of the drain back in place.

6.5.1.4 Lubrication of bearings with a drawerand rod for removing the greaseIn order to make the lubrication of the bearings, the oldgrease is removed by means of the device with a springinstalled on each bearing.

Lubrication procedure:1.Before starting the lubrication of the bearing, clean the

grease nipple with a cotton cloth;2.Remove the drawer and rod to remove the old grease,

clean the drawer and put it back;3.With the alternator running, inject the amount of grease

specified on the nameplate of the bearings using a manualgrease gun;

4.The excess of grease comes out through the bearinglower drain and is deposited in the drawer;

5.Maintain the alternator running long enough for thegrease excess to drain;

6.This grease must be removed by pulling the rod andcleaning the drawer. This procedure must be repeatedas many times as necessary until the drawer no longerretains grease;

Inspect the bearing temperature to ensure that there wasno significant change.

6.5.2 Bearing ChangeATTENTIONFor safety reasons, the change of bearingsmust be done with the alternator

disconnected from the driving machine.

To change the bearings on the alternator with doublebearing, it is necessary to disassemble the alternatorcompletely.

6.5.2.1 Bearing replacementThe disassembly of the bearings must always be donewith the use of appropriate tools (bearing puller).

Figure 6.1 Bearing extractor

ATTENTIONA bearing must only be removed from theshaft when absolutely necessary.

Instructions:1. The puller jaws must be placed on the side surface of

the bearing internal ring or on an adjacent part.2. Before the installation of the new bearings, the shaft

seats must be cleaned and slightly lubricated.

3. The bearings must be heated up to a temperaturebetween 50C and 100C to facilitate the assembly.

4. The bearings must not be subject to shocks, falls orstorage with vibration or humidity, which can causedents on the internal tracks or on the balls, reducingthe useful life.

6.6 MAINTENANCE OF THE EXCITER6.6.1 ExciterFor the proper performance of its components, thealternator exciter must be kept clean.Check the insulation resistance of the windings of the

main exciter and auxiliary exciter periodically so as todetermine the insulation conditions, following theprocedures described herein.

6.6.2 Diode testDiodes are components that last for a long time and donot require frequent tests. If the alternator presents adefect which indicates a diode fault or an increase in thefield current for the same load condition, then the diodesmust be tested in accordance with the followingprocedure:1. Disconnect all the diodes from the exciter rotor

winding;

2. With an ohmmeter, measure the resistance of eachdiode in both directions.


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NOTAWhen testing the diodes, observe the polarityof the test terminals in relation to the diodepolarity.The polarity of the diode is indicated by anarrow on its housing.

The current conduction must occuronly in the anode-cathode direction,i.e., in the condition of directpolarization.

The diode is considered good when you have low ohmicresistance (up to approximately 100) in its directpolarization and high resistance (approx. 1M) in theopposite direction. Defective diodes have ohmicresistance of 0 or greater than 1M in both directions. Inmost cases, the test method which uses an ohmmeter tothe diodes is enough to identify faults in the diodes.However, in some extreme cases it may be necessary toapply the rated blocking voltage and/or current circulationin order to detect a fault in the diodes. Due to all the workrequired to perform these tests, if you are not sure of theconditions of the diodes, it is recommended replace them.

6.6.3 Diode ReplacementIn order to replace the diodes, proceed as follows: Disconnect the six diodes from the exciter rotor; Install three new diodes of the same polarity (AND or

CTD) in one of connecting bridges; Install, on the other connecting bridge, three new diodes

with polarity opposite to that of the three diodespreviously installed;

Fix all the diodes, tightening them with a torque wrench,observing the torques ofTable 6.1;

Make the connections of the diodes with the exciterrotor winding.

ATTENTIONIt is vital that the tightening torques indicated beobserved so that the diodes will not be damagedin the assembly.

Table 6.1 - Tightening torque of the diodes

Thread of thediode base

(mm)

Torque wrenchnumber (mm)

Tighteningtorque (mm)

M6 11 2M8 17 4M12 24 10M16 32 30

6.6.4 Varistor testThe varistor is the device installed between the two diodeconnecting bridges and is intended to protect the diodesagainst overvoltage.To test the operating conditions of the varistor, anohmmeter can be used. The resistance of a varistor mustbe very high ( 20,000 ohms).In case of damages to the varistor or if the resistance is

very low, it must be replaced.

6.6.5 Varistor replacementIn order to replace the varistor, WEG recommends thatyou observe the following recommendations:1.Replace the damaged varistor by a new varistor

identical to the original one;2.In order to replace the varistor, loosen the screws that

fasten it to the diode connecting bridges ;

3.When removing the varistor, observe carefully how thecomponents were assembled so that the new varistorwill be installed the same way;

4.Before mounting the new varistor, make sure that all thecontact surfaces of the components are clean, leveledand smooth so as to ensure a perfect contact betweenthem;

5.Fix the new varistor by tightening the screws that fastenit to the connecting bridges just enough to make agood electrical connection.

6.7 AIR FLOWThe air inputs and outputs of the alternator must be kept

clear, so that the heat exchange is efficient. If the heatexchange is hindered, the alternator will overheat and thewinding may get damaged (burning of the alternator).

6.8 MAINTENANCE OF THE COOLINGSYSTEM

The tubes of the air-air heat exchanger (if applicable)must be kept clean and clear to ensure a perfect heatexchange. In order to remove the dirt accumulated inthe tubes, a rod with a round brush on the tip may beused.

In case of air-water heat exchangers, periodic cleaning

in the radiator pipes is necessary in order to remove anyfouling.

NOTEIf the alternator is equipped with filters in theair input and/or output, they must be cleanedwith compressed air.If the dust is difficult to remove, wash the filterwith cold water and mild detergent and thendry it in the horizontal position.

6.8.1 Maintenance of the radiatorsIf clean water is used, the radiator can remain in operationfor several years without the need for cleaning. With dirtywater, you need to clean it every 12 months.The level of dirt in the radiator can be detected by theincrease in the air temperature in the output. When thetemperature of the cold air, under the same operatingconditions, exceeds the specified value, it can beassumed that the pipes are dirty.If corrosion is found, it is necessary to provide adequateprotection (i.e., zinc anodes, plastic cover with plastic,epoxy or other similar protecting products) in order toprevent greater damages to the parts already affected.The external surface of all radiator parts must be alwayskept in good condition.


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Instructions for removing and servicing the radiatorThe removal of the heat exchanger for maintenance mustfollow the following steps:1. Close all the water input and output valves after the

ventilation is stopped;2. Drain the water through the radiator drain plugs;3. Remove the heads, keeping the screws, nuts and

washers and seals (gaskets) in a safe place;4. Brush the tubes inside carefully with nylon brushes for

removing residues. If during the cleaning damages tothe radiator tubes are found, they can be repaired;

5. Reassemble the heads, replacing the gaskets, ifnecessary.

6.9 ALTERNATOR OUT OFOPERATION

The following special care must be taken if the alternatorwill remain for a long period out of operation: Connect the space heaters for the temperature inside

the alternator to be kept slightly above the ambient

temperature, thereby preventing condensation andconsequent decrease in the winding insulationresistance and oxidation of metal parts.

All the radiators and water pipes (if applicable) must bedrained to reduce corrosion and deposit of materialssuspended in the cooling water.

Follow the remaining procedures described in itemExtended storageof this manual.Storage of the radiator after operationWhen the radiator remains out of operation for a longperiod, it must be drained and dried. Drying can be donewith preheated compressed air. During the winter, if thereis danger of freezing, the radiator must be drained, even

when it is out of operation for a short period, in order toprevent deformation or damage.

NOTEDuring short stops, it is preferable to maintainthe water flow at low speeds instead ofstopping its circulation, thus ensuring thatharmful compounds such as ammonia andhydrogen sulfide are taken out of the heatexchanger and do not settle inside.

6.10 SHAFT GROUNDING DEVICEIn some alternators, a brush is used for ground the shaft.This device prevents the flow of electrical current throughthe bearings, which is highly harmful to their operation.The brush is placed in contact with the shaft and connectedto the alternator frame, which must be grounded. Ensure

that the brush holder is fastened and connected correctly.

Figure 6.2 - Brush for grounding the shaft

The alternator shaft is protected with anticorrosive oil inorder to prevent damages during transportation andstorage. In order to ensure a perfect contact of thegrounding brush shaft, this oil, and any residue betweenthe shaft and the brush, must be removed before placingthe alternator start-up.The brush must be monitored constantly during operation,and at the end of its useful life, it must be replaced byanother of the same quality (grain).

6.11 COMPLETE CHECKUPThe frequency of checkups must be defined according tothe environment where the alternator is installed. The more

aggressive the environment (dirt, oil, sea breeze, dust,etc.), the shorter the checkup interval, as follows: Clean the dirty windings with a brush; Use a cloth moistened in a suitable solvent to remove

grease, oil and other impurities from the winding; Dry with dry air; Blow compressed air through the ventilation channels on

the lamination core of the stator, rotor and on thebearings.

NOTEThe compressed air must always be blownafter the cleaning; never before.

Drain the condensed water; Clean the inner part of the terminal box;

weg synchronous alternators naval application 12139384 manual english

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