let’s celebrate the glory of lord jagannath, to...
TRANSCRIPT
JULY 2018
Automation
Training Calendar
Piyush Patel (Managing Director)
Amtech Power Vision
Success springfrom calmness ofthe mind. It is acold iron which
cuts and bends hotiron.
Negative feedbackIt is a known fact that the performance of the control systems improvesdue to negative feedback. The output obtained is compared with theoutput desired and the error is used to correct the situation. In our life weget criticized for our actions, habits, mannerisms, performance and soon. The criticism is in fact an input to us; it is given to us free of cost mostof the times. But we tend to neglect it because we do not like it. We getnervous about it because it tells badly about us. But like a controlsystem, if we compare it with what we are expected of and analy e thes
gap between what we should be and what we are, then it can become the source for improvement.If we take proper action on this analysis, we can eventually achieve what is expected of us. In thisway our today’s weakness can become tomorrow’s strength; today’s crushing defeat can becometomorrow’s dazzling victory and our today’s criticizers become our admirers of tomorrow.
Techno-TalkSome fundamental
questions andanswers
Motor Control
Let’s Celebrate The Glory Of
Lord Jagannath, To Destroy The Evil From
The Face Of Earth.
-Amtech Family
Happy Rath Yatra !
KANPUR FERTILIZERS& CEMENT LIMITED
Customer’s Voice
Energy savingin cooler fan
Grabbing CraneModernization
Customer’s Voice
TRAINING CALENDAR
2018
2018
2018
2018
2018
2018
2018
2018
2018
2019
2019
2019
19-20
22-23
25-26
26-27
22-23
24-25
24-25
21-22
24-25
23-24
22-23
22-23
3
TECHNO-TALK
TITLE : SOME FUNDAMENTAL QUESTIONS AND ANSWERS
1. Whether fuse should be connected at load -end or source-end?
Fuse should be connected at source-end. At this location it will be able to protect from any short circuit in the cable atany point between source and load.
2. Whether Power Factor (PF) capacitor should be connected at load - end or source- end?
PF capacitor should be connected at load end. At this location, it will be able to avoid power loss in cable, as cable willnow carry less current due to reactive current compensation given by PF capacitor.
3. Why any equipment has to be derated at higher altitudes (typically at more than 1000 meters altitude)?
At higher altitudes air density reduces. Hence air available for cooling reduces. This reduces cooling provided by theair to the equipment. Hence the equipment cannot work at its rated capacity. Therefore it has to be derated at higheraltitudes.
4. Why high efficiency motors sometimes result in more power consumption than conventional motors?
High efficiency motors have lower slip than conventional motors. This results in high efficiency motors running atslightly higher speed than conventional motors. Centrifugal loads like fans, blowers, pumps, compressors etc.typically have their power consumption proportional to the cube of the speed at which they work. Hence with highefficiency motors they consume more power.
Consider the following example:
Conventional 4 pole motor, having efficiency of 85%, rotating at 5% slip connected to load consuming 100 kW power,
Speed of motor = 1500 (1 - 0.05) = 1425 RPM
Input power = 100 / 0.85 = 117.6 kW ---------------------------------------------------------------(1)
High efficiency 2 pole motor, having efficient of 90%, rotating at 2% slip, connected to same load.
Speed of the motor = 1500 (1-0.02) = 1470 RPM.
Now the power consumed by load, being proportional to cube of the speed,
= 100 (1470 / 1425) 3 = 109.8 kW
Hence input power = 109.8 / 0.90 = 122 kW ---------------------------------------------------------(2)
From (1) and (2) even if high efficiency motor is used its consumption will be 4.4 kW more then conventional motor, forcentrifugal type of loads.
5. Why two capacitors connected in series to share the voltage, need to be connected with resistors across
them?
Consider the following example:
Two capacitors 1000 uF/ 400 V are connected in series and put across 700 VDC voltage. Their leakage resistance isnot identical, they are 1 Mohm and 1.3 Mohm respectively.
Hence voltage across first capacitor will be = 700 x (1 / (1 + 1.3)) = 304 V
The voltage across second capacitor will be 396 V
The voltage difference between two capacitors will be 92 V---------------------------------(1)
Hence they will share the voltage unequally and one capacitor may even exceed its rated voltage. Now suppose, thecapacitors are shunted with 100 k resistance each, with 5% tolerance.
Hence their values in the worst case can be 95 k and 105 k. These resistors will be in parallel with the leakage resistorsof each capacitor.
The equivalent resistor across first capacitor will be = 95 x 1000/ (95 + 1000) = 86.8 k
The equivalent resistance across second capacitor will be = 105 x 1300/ (105 + 1300) = 97.1 k
Hence now the voltage across first capacitor will be = 700 x (86.8/(86.8 + 97.1)) = 330 V
Voltage across second capacitor will be 370 V
The voltage difference between two capacitors will be 40 V --------------------------------(2)
From (1) and (2) the voltage difference between two capacitors will be drastically reduced, even if we have taken theworst possible combinations of capacitors and resistors across them.
Hence now the capacitors will operate in safer operating conditions w. r. t. Voltages across them.
Additional advantage of resistors across capacitors is, when the 700 V across them is switched OFF the capacitorscan discharge to safe voltage value in about five minutes time, in this case.
DOC. NO. CS-267TITLE: ENERGY SAVING IN COOLER FAN
Payback Period Approximately = 4-5 Months
315 kW, 3-PHASEINDUCTION MOTOR
AXPERT-EAZY
3-PHASE,
415 V,
AC SUPPLY
355 kWCOOLER FAN
Industry : ementC
Application : ooler FanC
Motor rating : AC Induction Motor, 3 Phase-
315kW :
415V :olt
1485RPM :
: 50Hz
507A :mp
Previous system : Motor was running on DOLstarter.
Problem observed : 1) High maintenance cost.
.2) Energy losses due to flow control by damper
Present system : 3 kW55 Axpert-Eazy Variable Frequency Drive used.
kW (Consumption) Damper Position
Previous system
(Without drive) : 276 kW 85 to 97 % Open
Present system
(With drive ) : 222 kW 100 % Open
System block diagram :
Merits of new system : 1. Easy & mooth perations o .
2. Energy Saving due to flow control by VFD.
Economical analysis :
�Energy consumption without VFD- P1 = 276 kW
�Energy consumption with VFD - P2 = 222 kW
�Energy aving er ay ((P1-P2) 24) = 1296 Units.s p d x
�Saving er ay @ Rs.4/- Unit = Rs 5184 /-p d .
�Saving er ear (Approx. 300 Days) = Rs 5,55,200 /-p y . 1
FROM AMTECH POWER
5
Customer’s Voice
6
PRODUCT OVERVIEW
Title: Grabbing Crane Modernization
Frequent problems in grabbing cranes are:�The original system in grab control uses a differential limit switch to open/close
positions and these positions cannot be changed. As this system is purelymechanical, setting the position is a tedious process. The position of the switchcan be disturbed over multiple operations and to be reset again
�Power and Rotor resistance contactors often required to change due to frequentoperations
�Slip ring, carbon brushes maintenance�Arching, bigger size and bulkiness of motor puts extra load on trolley and bridge�Frequent problems in slip ring motors due to single phasing�Burning of resistor box�Regular maintenance of current carrying contacts of contactor due to frequent
braking and reversal involved�Motor and Gear box coupling bolts damage and subsequent motor and gearbox
damage due to jerky operations�Hoist & Grab wire rope breakage due to uneven load sharing�Poor life of brake shoe as brakes are used for braking the speed
The new generation of control and monitoring system, developed by Amtech Electronics (India) Ltd, integrates the operation of EOT cranewith four rope grab using variable frequency drive and crane controller.Grabbing crane used to handle the powder material, has four ropes which controls hoisting and grabbing operation. Synchronization of thisoperation was carried out by differential gearbox. Being mechanical synchronization, it is prone to backlash and takes lot of time to re-synchronize. Amtech has developed and successfully installed automation system for the grabbing crane. Automation system controls thesynchronization of whole crane operation like Cross Travel, Long Travel, Hoisting, Grabbing and safety interlocks. Automation system isusing properly sized variable frequency drive for existing slip ring motor or new induction motor to control the operation. PLC system takescare of Speed control, Thruster control, Synchronization and Various interlocks.
Grab crane is a type of crane used in Cement, Metal industry, Ports etc. for handlingof material in powder form. The grab mechanism is just like two jaws hinged at mid-point, used to grab the material. This mechanism can be operated by either hydraulicor electrical system. In Hydraulic system the grab jaws are operated by hydrauliccylinders. In case of electrical system, there are two rope-end-drum assemblies onthe crab trolley. The grab operation is carried out by one of the rope-end-drumassembly used to hoist the grab which in turn, gets driven by electrical motor. Themotors are controlled by drive to allow multiple speed operations.
Features�Retrofitting the crane using existing slip ring motor/new induction motor�Removing the mechanical differential gearbox limit switch operation�Close loop control with encoder feedback from rope drum, to synchronize Hoisting
and Grabbing operations with equal load sharing�For the crane operator, the crane works as if there were only a single hoisting
device with the additional functions of “open” and “close”. Setting the nominal grabpositions only has to be performed once after a change of a rope or grab unit
�Latest series variable frequency drive with state-of-the-art engineered panel withprotection of crane vibration in dusty environment, ensures trouble freeoperation of the crane
�Operator cabin is equipped with monitoring system, which gives status of wholecrane operation makes the operation easy for operator.
�User friendly HMI provides powerful diagnostics in case of problem and reducesdowntime
�Variable frequency drive control eliminates problems associated with slip-ringmotor contactor, resistor and thruster brake
Benefits�Assistance from concept to commissioning�New system with existing components�Minimized maintenance reduces ownership cost and provides more up time�Ease of setting Open/Close limits through HMI instead of adjustment of
mechanical limit switch�Optimized four-rope grab control minimizes cycle time and reduces stress on
ropes�Higher reliability - Less Mechanical wear / tear – more uptime
OPEN/CLOSEROPE DRUM
HOLD DRUM
HOIST PULLEY
OPEN/CLOSE PU
GRAB CLOSEDGRAB OPENED
�Full motor protection�Smooth crane operation�Electronic braking, hence reduced maintenance of
brake�Energy saving�Easy troubleshooting�Quick and safe commissioning�Qualified after-sales service
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CUSTOMER’S VOICE
Gandhinagar
Atlanta
GandhinagarAhmedabad
Mumbai
Surat
MuzaffarnagarDelhi(Gurgaon)
Vadodara
Indore
Jamnagar
Udaipur
Kolkata
Nagpur
Pune
Hyderabad
Vapi Raipur
Bhopal
Jamshedpur
JaipurLucknow
Vizag
Bangalore
Chennai
Belgaum
PondicherryTrichy
AurangabadNasik
Chandigarh
Veraval
M. D. Kamath
Paresh Patel
Regional Offices
Contact Person Phone No. (O) Mobile No. E-mail
022-28846083Vrajesh Yadav 09819900501
09108051977
09825042458
Mumbai
Bangalore
Chennai
Delhi
T. S. Sridhar 09840618533 09940229955
.
Umesh Bhatia 09589344318Indore / Raipur [email protected]
H.O. and Service Center
Contact Person Phone No. (O) Mobile No. E-mail
Shailesh Patel 09879208780H.O. Gandhinagar [email protected]
Rajesh Moradiya 09909973780Amtech Service CenterGandhinagar
G. Sateesh Kumar 09573900222Hyderabad [email protected]
Kaushik C. 09932820680Kolkata [email protected]
09825042458
09589344318
09573900222
09932820680
09108051977
Pankaj Gulati 09888748620Chandigarh [email protected]