electrical design lectures

8/10/2019 Electrical Design Lectures

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ELECTRICAL DESIGN LECTURES:

SIZE AND RATINGS

Service entrance conductors shall be sufficient size to carry the computed loads.

CLEARANCE OVER THE ROOF (CONDUCTORS OF NOT MORE THAN 600 VOLTS):1. 2500 mm (8 feet) - without elevation2. 1000 mm (3 feet) - without elevation

CLEARANCE FROM GROUND (CONDUCTORS OF NOT OVER 600 VOLTS)

4. 5500 mm - over public streets, alleys roads and driveways on other than residential property.Note : (drawing is based on NEC standard)

UNGROUNDED CONDUCTORS SHALL NOT BE SMALLER THAN:1.100A, 3- wire, for one family dwelling with six or more 2 branch circuit.

2.100A, 3-wire, for one family dwelling with an initial computed load of 10-kw or above.3. 60A for other loads.

EXCEPTIONS:

INSTALLATION OF SERVICE CONDUCTORS:

1. Open wiring on insulators2. Rigid metal conduit (RMC)3. Intermediate Metal Conduit (IMC)4. Electrical Metallic Tubing (EMT)5. Service-entrance cables6. Wireways7. Busways8. Auxiliary Gutters9. Rigid non-metallic conduit10. Cable Bus11. Type MC cable12. Mineral-insulated metal-sheathed cable

PROTECTION:

1. By RMC2. By IMC3. By Rigid Nonmetallic Conduit suitable for the locations4. By EMT5. Type MC Cable or other approved means

GENERAL:

IMPORTANT PARTS OF AN ELECTRICAL DESIGN

1. For loads consisting of not more than two wire branch circuit, 8 mm 2 (3.2 mm dia.) copper or 14 mmaluminum or copper clad aluminum.2. By special permission, for loads limited by demand or by the source of supply, 8mm 2 copper or 14maluminum or copper-clad aluminum.

3. For limited loads of a single branch circuit 3.5mm 2 copper or 3.3mm 2 aluminum or copper-clad alumin

Service entrance conductors shall be installed in accordance with the applicable requirements of this code(PEC) covering the type of wiring method used and limited to the following methods:

THE SERVICE ENTRANCE CONDUCTORS

Power is supplied to a building through a service entrance. Three heavy wires, together called the drop, extend from autility pole or an underground source to the structure. These wires are twisted into a cable. At the building, overhead wiresare fastened to the structure and spliced to service entrance wires that enter a conduit through a service head, as shownin Figure 31-1

Service drop shall have sufficient ampacity to carry the load. They shall not be smaller than 8mmdiameter) copper or 14 mm 2 aluminum or copper clad aluminum

1. 3100 mm - above finished grade, sidewalks or from any platforms or projection which may be reached.

2. 3700 mm - over residential driveways and commercial areas such as parking lots and drive-inestablishments not subject to truck traffic.

3. 4600 mm - over commercial areas, parking lots or agricultural or other areas subject to truck traffic.

Service entrance conductors shall be installed in accordance with the applicable requirements and subjected to

any of the following ways or methods:

THE SERVICE EQUIPMENT-DISCONNECTING MEANS

The Service Equipment-Disconnecting Means shall be provided to disconnect all conductors in a building orconductors.

In planning overhead service drop paths, minimum height requirements for connector lines must be carefully followed.See Figure 31-2. If these distances cannot be maintained, rigid conduit, electrical metallic tubing, or busways (channels,ducts) must be used.

If the service is supplied underground, three wires are placed in a rigid conduit. An underground service conduit isbrought to the meter socket. An underground service entrance includes a watt-hour meter, main breaker, and lightningprotection. Automatic brownout equipment is also required by many codes for new construction. All electrical systemsmust be grounded through the service entrance.


2/23


3/23

Lighting Design Lecture

Light Measurements

Types of LightingThe three basic types of lighting are general lighting, specific lighting, and decorative lighting.

LightDistribution

fc (54 to 108lx). A higher level of general lighting should be used in the service area and bathrooms. Many genefixtures can also be used for decorative lighting by a connection to dimmer switches.

Human eyes adapt to varying intensities of light. However, they must be given enough time to adjust slowlychanges of light may cause discomfort. Light intensity is measured in units called foot candles. A foot candlcasts on an object one foot away. See Figure. 31-8. Ten foot candles (10 fc) equals the amount of light that taway. In the metric system, the standard unit of illumination is the lux (lx). One lux is equal to 0.093 fc. To conSee Fig. 31-9.

Functional lighting design must consider the interaction among eyesight,objects, and light sources. Good lighting design provides sufficient but notexcessive light. Glare from unshielded bulbs or improperly placed lightingshould be avoided. Excessive contrast between light and shadows withinthe same room should also be avoided, especially in work areas.

For centuries, candles and oil lamps were the major source of artificiallight. Although candles continue to function for special effects, the major sources of light today are incandescent and fluorescent lamps.Incandescent lamps have a filament (a very thin wire) that gives off lightwhen heated. Fluorescent lamps have an inner coating that gives off visiblelight when exposed to ultraviolet light. The ultraviolet light is released by agas inside the fluorescent tube. Incandescent lamps concentrate the lightsource, while fluorescent lamps provide linear patterns of light. Fluorescentlamps give a uniform glare less light that is ideal for large working areas.Fluorescent lamps give more light per watt, last seven times longer, andgenerate less heat than incandescent lamps.

GENERAL LIGHTING: General lightingprovides overall illumination and radiates acomfortable level of brightness for an entireroom. See Fig. 31-10. General lightingreplaces sunlight and is provided primarilywith chandeliers, ceiling or wall-mountedfixtures, and track lights. To avoid contrastand glare, general lighting should be diffusedthrough the use of fixtures that totally hide thelight source or that spread light throughpanels. Close spacing of hanging fixtures alsocreates diffuse lighting. Another solution is touse adjustable fixtures so that the light can bedirected away from eye contact. W herepossible, daylight should be included as a partof the general lighting plan during daylighthours. If adequate window light is notavailable, the use of skylights should beconsidered. The intensity of general lightingshould between 5 and 10

DECORATIVE LIGHTING: Bright lights arestimulating, while low levels of light arequieting. Decorative lighting is used to createatmosphere and interest. Indoor decorativelights are often directed on plants,bookshelves, pictures, wall textures,fireplaces, or any architectural feature worthyof emphasis. Some decorative lighting can beused as general lighting through the use of dimmer switches. Outdoor decorative lighting

can be most dramatic. Exterior structural andlandscape features can be accented by well-placed lights. Outdoor lighting is used to lightand accent wall textures, trees, shrubs,architectural features, pools, fountains, andsculptures. See Fig. 31-12. Outdoor lighting isespecially needed to provide a safe view of stairs, walks, and driveways. Remember to

conceal light sources and don't over light. use waterproof devices and an automatic timing device to turn lights on a


4/23

Example:

GeneralDescription (3)

Typical Application

(4)Type (5) Quantity x w/

lamp (6)Lamp Holder

(7)Supp

1. Legend used2. Item Number 3. Standard description. Example:

4. Where fixture will be mostly likely to be used5. Ballast type: Electronic or Electromagnetic6. Lighting Fixture Quantity7. Type of lamp holder: Twistlock type or Spring type.8. Voltage requirement9. Number of lamp times lamp wattage10. Supplier description and catalog number (if available)11. Other particular items (dimensions and Gauge size).

For Gauge Size use the following table for referenceTable 1: Gauge Size

ImperialGauge

Imperial inmm

Metric sheetmm

10.00 3.25 3.0012.00 2.64 2.5014.00 2.03 2.0016.00 1.63 1.5018.00 1.22 1.2020.00 0.91 0.9022.00 0.71 0.7024.00 0.56 0.6026.00 0.46 0.50

2. Feed lines and protective devices of motors, electrical equipments and appliances indicating types and ratings.3. Size of branch circuit wires, feeders, sub-feeders and busbars including protective devices.4. Size and type of service entrance wires, raceways and equipment.

In designing building load. It is essential to consider the simultaneity factor (demand factor) to deA p p ro x im ate Valu es fo r s im u ltan eity fac to rs to co n su m ers

OfficeBuilding

Industr ial Hospitals

0.80-0.90 0.95 0.70-0.900.20-0.40 0.10 0.10-0.200.70-0.90 0.80-1.00.80-1.0 0.80-1.0 0.80-1.00.80-1.0 0.90-1.0 0.90-1.0

0.60-0.75 0.60-0.75 0.60-0.600.50-0.70 0.30-0.90 0.80-1.0

0.80-0.900.30-0.40 0.35-0.45 0.60-0.850.70-0.80 0.30-0.70 0.60-0.80

Depth below si te surface for buried conn ections (according to DIN 18012 Europ ean Standard)

Land Surface

35 - 60 cm 50 - 100 cm

communications supply 60 - 80 cm gas supply

high voltage supply 60 - 100 cm

district heat supply

120 - 150 cm

water supply

5. Settings / ratings of overcurrent devices.For items 2 to 5 consider the following:a. The maximum allowable voltage drop per wire.

Table 2: Maximum Allowable voltage drops (percent)

F Li hti F

System

LightingOutletsHVAC

Surface-mounted two lamp-40 watts, 230 VAC Industrial-type fluorescent lighting fixture with dihigh pf energy saving ballast.

Item Number(2)

General Description and Application

OthersTotal

Symbol (1)

Lamp and Power Data

RefrigerationKitchens

0.60-0.70Elevators

Hoisting Equipment

0.80-1.00.90-1.0

0.60-0.80

0.70-0.900.10-0.25

Heating

0.30-0.600.30-0.60

Residentials


5/23

II. For Straight Pull:

25mm

b.2 with respect to voltage dropUse the following computation in determining the voltage drop

CM = (25 x I x L) / Vdrop (based on NEC computation)where: CM = circular mil

I = Full Load current (100%)L = Length (in feet)V drop = Voltage Drop (see table 2 for reference)

Sample:Panelboard LP A @ 100% load: 117.76 Amperes

Distance from Panelboard to EE room: 80 metersCM = (25 x I x L) / Vdrop

where : I = 117.76 AL = 80m(100cm / m)(1 in / 2.54cm)(I ft / 12in) = 262.47feeV drop (set at 5%) = 240 x 0.05 = 12.0v

CM = (25 x 117.76 x 262.47) / 12.0= 64,392.64 CM

A = d 2 finding dd = sq.rt (64392.64)

= 253.76= 253.76 CM (1in / 1000mils)(25.4mm/in) = 6.445 mm

A = 3.1416 x (6.445) 2 / 4 A = 32.63 mm 2 or 38 mm 2 safe

therefore Use 1 set of 3 #38mm 2 and 1 #22mm 2 THHN in 40 IMC

NUMBER OF DISCONNECTING MEANS:

LOCATION:

RATING:

The service disconnecting means shall have a rating not less than the load to be carried.

IN NO CASE SHALL THE RATING BE LOWER THAN SPECIFIED THROUGH:a. ONE CIRCUIT INSTALLATION - The service disconnecting means shall have a rating of not less than 15 amb. TWO CIRCUIT INSTALLATION - The service disconnecting means shall have a rating of not less than 30 am

1. Where the initial computed loads is 10 KW or more:2. Where the initial installations consist of six or more 2 wire branch circuit.

d. ALL OTHERS - for all other installations the service disconnecting means shall have a rating of not less than 60Note:

-

- The service entrance conductors shall have a short-circuit protective device in each underground conductors.- Fuses shall have an interrupting rating not less than the maximum available short circuit current in the circuit at the-

ELECTRICAL WIRING DESIGN OF A SINGLE FAMILY DWELLINGPrinciples:

1. Secure the architectural plan of the building to be lighted.2. Determine the loads and systems to be provided like air-conditioning units , electric range, washing machine and

3. Determine the location and concentration of loads and specify the location of electrical devices, appliances and

The service disconnecting means for each set or for each sub-set of service entrance conductors shall consist ofbreaker mounted in a single enclosure, in a group of separate enclosures, or on a switchboard.

The service disconnecting means shall be installed either inside or outside of a building or other structure at apoint of entrance of the service entrance conductor.

c. ONE FAMILY DWELLING - The service disconnecting means shall have a rating of not less than 100 amconditions:

The service disconnecting means shall simultaneously disconnect all ungrounded conductors and shall be cgreater than the maximum available short-circuit current.

Circuit Breakers shall be free to open in case the circuit is closed in the overload. Circuit Breakers shall hamaximum available short-circuit at its terminals.

b.1.4 When the conductors need to be spliced, a junction box is required. No conductor is al

In straight pulls, the length of the box should not be less than eight timlargest lock nut and bushing of the conduit including the spacing between the

L

40mm


6/23

1 - 5kw washing machineUsing conventional method (Area method), design the electrical system.

Co mp u ta t io n s :

For General Lighting load (150m 2) x (24 W/m 2) = 3 For small appliance load = 3,000

compute load without electric range 6,600. Application of Demand Factors

First 3000 at 100% demand factor = 3,000. Excess of 3000VA (6600-3000) at 35% = 1,260.0

4 Other Loads:Electric Range = 8,0 washing Machine = 5,00 Two 1 Hp air conditioning unit (2 x 8 x 230) = 3,680. water Heater = 2,5 One 1/2 Hp ACU (4.9 x 230) = 1,12 25% of largest motor (0.25 x 8 x 230) = 460.

Total Computed load with electric range 25,027.0


7/23

Main Feeder full load current:IL = 25027 / 230 = 108.81 amperesFor Main Feeder service entrance conductor:Use 2 - 38mm 2 THW copper conductor (minimum)Use 125A , 250V, 2 pole Circuit Breaker, 300AF

For Service neutral conductor:IN = 70% (108.81) = 78.17 amperesUse 1 - 22mm 2 THW copper conductor

Size of Conduit:Use 32mm phase rigid steel conduit (RSC)

Load ScheduleCircuit No. L.O. C.O Switch Power Volta

2 10 10 320w 233 8 1440w 24 8 1440w 25 12000w 26 5000w 27 28 29 2

10 2

Design the electrical system of a single family with one hundred sq meters (100 sq. m) and with the following connected loads:2 small appliances at 1500 w eachOne 15 kw electric rangeOne 4.5 kw electric rangeOne 1.2kw washing machineOne 5kw clothes dryer Two 1.5Hp ACUOne 3/4 Hp ACU

Compute for the size of the feeder and the main circuit breaker

Co mp u ta t io n s :

General Lightning Load (100sqm (24w / sqm) = 2,400.0 Small Appliance Load = 2(1500) = 3,000

total computed load without fixed appliances 5,400.0 Application of Demand factor:First 3000 w at 100% demand factor = 3,000. excess at 35% demand factor = 840

total computed load without fixed appliances 3,840.0 Other load:

One 15kw Electric range = 8 + 8(15-12)5% = 9,200.0 One 4.5kw oven = 4.5(80%) = 3,600 One 1.2kw washing machine = 1,200

One 5kw clothes dryer = 5,00 total computed load without ACU 22,840 computed current, I = 22840 / 230 = 99 Two 1 1/2 Hp ACU = 2(10) 20.0One 3/4 Hp ACU 6.9

Plus 25% of the full load current of highest motor 2.5 total load current 1

Maximum Ampacity of subfeeder circuit:I = 125% (128.7) + 25%(10) = 163.38

Therefore:Use: 2 - 60mm 2 THWNote: 125% is for safety allowance

Subfeeder neutral conductor (line to line voltage 230):small appliance load = 3,00 electric range = 9200 (70%) = 6,440 oven = 3600 (70%) = 2,55 clothes dryer = 5000 (70%) = 3,500 total load 15,4 Neutral currentI = 15490 w / 230 v = 67.2I = 67.22 (125%) = 84.0

Use: 2 - 60mm 2 THW copper conductor 1 - 30mm 2 THW co er conductor

d i i 1 40 di Ri id S l C d (RMC)

8 - 40 watts

1 - 5kw Washing Machine

400w 2

Load Description

10 - 40 w Fluorescent Lamp

1 - 12kw Electric Range

1 Hp - ACU

1 Hp - ACU1 Hp - ACU

One 1/2Hp ACU

8 - 180 watts8 - 180 watts

1 10 10


8/23

Therefore:use : 4 - 200mm 2 THW copper conductor 1 - 125mm 2 THW copper conductor conduit : use 2 - 80mm dia RSC

Maximum ampacity of feeder circuit overcurrent protective device:use 600AT / 1000AF, 250V circuit breaker

DESIGN OF COMMERCIAL BUILDING

Less than 400 sq. ft - Provide at least 1 convenience outlet for every 20 ft (6 meters).First 400 sq. ft or 37 sq. m----------------------------------------------- 4 convenience outlet

Additional 400 sq. ft------------------------------------------------------- 2 convenience outlet Fraction--------------------------------------------------------------------- 2 convenience outlet

LOAD SCHEDULES

Panel Board LPA

F T P 100w 40w S1 S21 50 15 2 10 42 50 15 2 83 50 15 2 84 50 15 2 85 50 15 2 86 50 15 2 8 17 50 15 2 5 4 38 50 15 2 99 50 15 2 12

10 50 15 2 11 3 111 50 15 2 10 2 112 50 15 2 8 413 50 15 2 12

14 50 15 2 8 315 50 15 2 8

16 50 15 2 10

17 50 15 2 Spare18 50 15 2 Spare19 50 15 2 Spare20 50 15 2 Spare21 50 15 2 Space

Panel Board LPB

F T P 100w 40w S1 S2

1 50 15 2 102 50 15 2 93 50 15 2 64 50 15 2 95 50 15 2 96 50 15 2 127 50 15 2 108 50 15 2 9 19 50 15 2 8

10 50 15 2 1011 50 15 2 10 212 50 15 2 10 213 50 15 2 Spare14 50 15 2 Spare15 50 15 2 Spare16 50 15 2 Space

Panel Board LPC

F T P AB C1 50 15 2 4.702 50 15 2 4.703 50 15 2 44 50 15 2 45 50 15 2

66

Ckt. No.Circuit Breaker Rating Load Description

67

C.O 180 VA6

Phase C

Ckt. No.Circuit Breaker Rating Load Description Swit

Ckt. No.Load DescriptionCircuit Breaker Rating

Note : Washing machine may be included in small appliance load, however, washing machine is not included in ot


9/23

Panel Board PPB

F T P AB1 50 30 2 10.002 50 30 2 10.00

3 50 30 2 124 50 30 2 125 50 30 26 50 30 27 50 20 2 8.008 50 20 2 8.009 50 30 2 10

10 50 30 2 1011 50 20 212 50 20 213 50 30 2 12.0014 50 20 2 8.0015 50 20 2 8.0016 50 20 2 8.00

17 50 20 2 8.0018 50 30 2 10.0019 50 30 2 10.0020 50 30 221 50 30 2 10

Total 100.00 54

Main Distribution Panel MDP

AB CA BC 31 34.27 34.79 34.73 0.002 26.52 27.83 24.35 0.003 24.10 10.96 19.40 0.004 20.18 9.40 19.40 0.005 58.00 56.00 60.00 9.606 66.00 64.00 70.00 0.007 0.00 0.00 0.00 0.008 0.00 0.00 0.00 0.00

Total 229.07 202.98 227.88 9.60

ComputationsI 3E = 9.6 + 1.73(229.01) = 406.26 A If exceeds 267 A initial load,

Allowance 20% = 1.20 (406.26) = 487.50 AMATCC = 406.26 + 1.73(0.25)(12) = 411.45

Use : 3 - 325 mm 2 THW (435 / 411.45 A) RS and 80mm6 - 100 mm 2 THW (220 / 205.73A) 50mm

9 - 50mm2

THW 145 / 137A 40mm

MROFCCPD = 30 + 1.73(229.01-12) + 9.6= 415.47A (1.2)= 498 A

Use : 500 AT / 600AF, 3P, ACB Type LA

Panel Board LPA

1 15.00 15

2 15.00 15

3 15.00 154 15.00 15

5 15.00 15

6 15.00 15

7 15.00 158 15.00 15

9 15.00 15

10 15.00 15 5

11 15.00 15 5

12 15.00 15 5

13 15.00 15 514 15 00 15 5

2 - 3.5 - TW

2 - 3.5 - TW

2 - 3.5 - TW

2 - 3.5 - TW2 - 3 5 - TW

2 - 3.5 - TW2 - 3.5 - TW

2 - 3.5 - TW

2 - 3.5 - TW2 - 3.5 - TW

2 - 3.5 - TW

8(100) / 230 = 3.48A

No., type and size of wire(mm 2)

2 - 3.5 - TW

2 - 3.5 - TW

10 (100) / 230 = 4.35A

2 - 3.5 - TW

11(100) / 230 = 4.78A

10(100) / 230 = 4.35A

8(100) / 230 = 3.48A

12(0.43) = 5.16A8(100) / 230 = 3 48A

AT

8(100) / 230 = 3.48A

5(100)/230 + 4(0.43) = 3.899(100) / 230 = 3.91A

12(0.43) = 5.16A

Phase Current I

8(100) / 230 = 3.48A

8(100) / 230 = 3.48A8(100) / 230 = 3.48A

Spare

Ckt. No.

SpareSpare

Diameter ofRSC

SpareSpareSpare

1 - HP ACU1 - HP ACU

1 - HP ACU


1 - HP ACU

1.5 - HP ACU1 - HP ACU

1.5 - HP ACU

1.5 - HP ACU


1.5 - HP ACU

Phase C

1.5 - HP ACU

2 - HP ACU

Ckt. No.Circuit Breaker Rating

2 - HP ACU

Load Description

C.O 180 VA1.5 - HP ACU

Ckt. No.Panel No.,

Designation

Phase Current

LPBLPA

PPA

LPCLPD

PPB


10/23

Panel Board LPD

1 15.00 15 5

2 15.00 15 5

3 15.00 15 5

4 15.00 15 55 15.00 15 5

6 15.00 15 57 Stub Out8 Stub Out

Panel Board PPA

Full Load Ampere AmpereCurrent Trip Frame

1 1 HP = 8A 2.5(8) = 20 50

2 8 20 50

3 8 20 50

4 8 20 505 10 2.5(10)=25 or 30 50

6 8 20 50

7 8 20 50

8 8 20 50

9 8 20 50

10 8 20 50

11 8 20 50

12 10 30 50

13 8 20 50

14 8 20 50

15 10 30 50

16 8 20 5017 9.6 2.5(9.6)=24 or 30 50

18 10 30 50

19 10 30 5020 10 30 5021 10 30 50

Panel Board PPB

Full Load Ampere AmpereCurrent Trip Frame

1 10 30 50

2 10 30 50

3 12 30 504 12 30 50

5 10 30 50

6

7 8 20 50

8 8 20 50

9 8 20 50

10 8 20 50

11 8 20 50

12 10 30 50

13 8 20 50

14 8 20 50

15 10 30 5016 8 20 50

17 9.6 2.5(9.6)=24 or 30 50

18 10 30 50

19 10 30 5020 10 30 5021 10 30 50

LPA Details LPB Det

21 - 3.5 - TW

12.50 19 - 3.5 - TW12.50 20 - 3.5 - TW

1.25(9.6) = 12 17 - 3.5 - TW

12.50

12.50 18 - 3.5 - TW

Ckt. No. Phase Current INo., type and size of wire

(mm 2)Diameter of

RSCAT A

7(180) / 230 = 5.48A 2 - 3.5 - TW

16 - 3.5 - TW

6(180) / 230 = 4.7A 2 - 3.5 - TW

6(180) / 230 = 4.7A 2 - 3.5 - TW

10.00

6(180) / 230 = 4.7A 2 - 3.5 - TW2 - 3.5 - TW

10.00

12.50 15 - 3.5 - TW

Spare = 10 2 - 3.5 - TW

8 - 3.5 - TW

10.00 9 - 3.5 - TW

6 - 3.5 - TW

6(180) / 230 = 4.7A

6(180) / 230 = 4.7A 2 - 3.5 - TWSpare = 10 2 - 3.5 - TW

14 - 3.5 - TW

Ckt. No.

12.50 12 - 3.5 - TW

10.00 13 - 3.5 - TW

10.00 10 - 3.5 - TW

10.00 11 - 3.5 - TW

10.00

10.00 7 - 3.5 - TW

10.00 4 - 3.5 - TW

1.25(10) = 12.5 5 - 3.5 - TW

10.00 3 - 3.5 - TW

Max Ampacity of Motor Br.Ckt. Conductor

1.25(8) = 10

1.25(8) = 10

10.00

10.001.25(10) = 12.5

10.00

1.25(8) = 10 2 - 3.5 - TW

No, Type and Size of wi

2 - 3.5 - TW

10.00

10.00

12.50

2 - 3.5 - TW

10.00 2 - 3.5 - TW

10.00

2 - 3.5 - TW

10.00

Ckt. No. Max Ampacity of Motor Br.Ckt. Conductor No, Type and Size of wi

2 - 3.5 - TW

1.25(8) = 10 2 - 3.5 - TW

2 - 3.5 - TW

1.25(9.6) = 12 2 - 3.5 - TW

12.50 2 - 3.5 - TW

2 - 3.5 - TW

12.50 2 - 3.5 - TW

10.00 2 - 3.5 - TW

2 - 3.5 - TW

2 - 3.5 - TW2 - 3.5 - TW

2 - 3.5 - TW

12.50 2 - 3.5 - TW

10.00

10.00 2 - 3.5 - TW

12.50

2 - 3.5 - TW

2 - 3.5 - TW

2 - 3.5 - TW

2 - 3.5 - TW

12.50

A B C A B


11/23

PPA Details

RISER DIAGRAM

GND

GNDGND

Riser : Single Line Diagram (Not to Scale)Required Grounding conductor is No. 50mm 2 THW

GROUNDING ELECTRODE CONDUCTOR FOR AC SYSTEM: Minimum Size of grounding Conductor / Equipment:

Rating of Over CurrentProtective Device Size of m

Size of Largest ServiceEntrance Copper (mm 2)

Size of Grounding ElectrodeConductor Copper (mm 2)

1

7

3

5

9

13

15

11

19

17

A B C

1 2

4

7

3

5

9 10

8

18

6

12

16

13 14

15

20

11

19

17

21 22

21

PPB LPD LPB

PPA LPC LPA MDP

WIRE GUTTER


12/23

DESIGN OF AN INDUSTRIAL PLANT

Maximum Number of Outlets Required:Manufacturing Spaces ...... ...Storage Spaces ...... ...Offices ...... ...For every 40 watts fluorescent lamp, the input power (high power factor ballast) ... ..

For every 40 watts fluorescent lamp, the current drawn by the ballast is.....

For ordinary 20 watts fluorescent lamp, the current drawn by the ballast is .....For every convenience outlet (duplex), the power is ........ ..

Note: Provide at least one spare branch circuit for every five branch circuits.Maximum Ampacity of Motor (Branch circuit conductor) .. .

For Fused-Motors .. .. Maximum Ampere rating of the Motor Circuit Breaker .......

That is for 1 and 3 motors with Full Load current less than 30 amperesMaximum Ampere rating of the Motor Circuit Breaker ..

That is for 3 motors with Full Load current more than 30 amperesNote: Feeder conductors / branch circuit conductors for lighting, small appliance and similar load

10.8

LOAD SCHEDULE FOR PANEL BOARD LP

1 230 82 230 83 230 74 230 65 230 66 230 67 230 58 230 59 230 18

10 230 1411 230 512 230 513 230 1214 230 1115 230 1816 230 1817 230 1118 23019 23020 230

Maximum Ampacity of the Feeder CurrentWire (mm 2) Conduit (mm) = 1.25 (1.73)(largest phase current)

1 2 - 3.5 TW 15 RSC = 1.25(1.73)(53.37)2 2 - 3.5 TW 15 RSC = 115.546 Amperes3 2 - 3.5 TW 15 RSC4 2 - 3.5 TW 15 RSC5 2 - 3.5 TW 15 RSC6 2 - 3.5 TW 15 RSC7 2 - 3.5 TW 15 RSC8 2 - 3.5 TW 15 RSC9 2 - 3.5 TW 15 RSC

10 2 - 3.5 TW 15 RSC11 2 - 3.5 TW 15 RSC12 2 - 3.5 TW 15 RSC13 2 - 3.5 TW 15 RSC14 2 - 3.5 TW 15 RSC15 2 - 3.5 TW 15 RSC16 2 - 3.5 TW 15 RSC17 2 - 3.5 TW 15 RSC18 2 - 3.5 TW 15 RSC19 2 - 3.5 TW 15 RSC20 2 - 3.5 TW 15 RSC

LOAD SCHEDULE FOR PANEL BOARD PPA

1 230 1 1,840.00 82 230 1 6 440 00 28

Fluorescent Lamp

= 1.25

Ckt. No. Volts LightingOutlet

Freezer (5 1/4 HP each)

ConvenienceOutlet

Sw

Ckt. No.Size of Homerun

Freezer (5 1/4 HP each)Fluorescent LampsFluorescent Lamps

Fluorescent Lamp 24 I.L.Fluorescent Lamp 32 I.L. 2

Freezer (5 1/4 HP each)

Ckt. No. LOAD DESCRIPTION

Fluorescent Lamps

LOAD DESCRIPTION

Duplex Convenient Outlet

Fluorescent Lamps

Ampere percircuit

SpareSpareSpare

Duplex Convenient OutletDuplex Convenient OutletDuplex Convenient OutletDuplex Convenient OutletDuplex Convenient OutletFreezer (5 1/4 HP each)

ACU, 1HPSilent Cutter, 5HP

Volts Phase VA per circuit


13/23

MAFCC = 10 + 1.73(59.4-28) + 1.25(1.73)(28) = 10+1.73*(78= 126.73 Amperes = 157

Use : 3 - 50mm2 THW, 145A / 126.73 A in 40mm RSCPMROFCOPD = 70 + 1.73(31.4) + 10 = (10+1.73*7

Use : 150 AT / 200AF, 3P, 250V C.B. = 193.71

SUMMARY OF LOADS MDP

AB BC C230 3 25,068.00 46.94 51.38 230 3 80,850.00 51.20 50.60 230 3 42,672.00 59.40 54.80 230 3 37,647.00 230 3 37,647.00

Total 157.54 156.78 151.3

Note : The Efficiency of the Meat Cutter is assumed to be 85% and the power factor is assumed to be 80Meat Cutter I FL = = 118.13

MAFCC = 1.25(118.13)=147.66 Amperes

Use : 3 - 60mm2 THW, (160A / 147.66A) in 40mm RSCPMROFCOPD = 2(118.12)

= 236.26 AmperesUse : 250AT / 400AF, 3P 250V motor branch circuit breaker

MDP:Minimum Ampere = 1.73(157.54) + (359.26 - 118.13) + 1.25(118.13)

= 662 AmperesUse : 2 sets of 3 - 250mm2 THW (750 / 622A), in 80mm RSCP

Maximum ROFCOPD = 250 + (359.26 - 118.13) + 1.73(157.54)= 763.98 Amperes

Use : = 800AT / 800Af, 3P 250V Main Feeder C.B.

COMPUTATION

1 20 50 2 - 3.52 70 100 2 - 83 30 50 2 - 3.54 30 50 2 - 3.55 30 50 2 - 3.56 30 50 2 - 3.57 50 50 3 - 5.58 70 100 3 - 8.09 20 50 3 - 3.5

10 20 50 3 - 3.511 100 100 3 - 2212 20 50 3 - 3.513 20 50 2 - 3.514 20 50 2 - 3.515 20 50 2 - 3.516 70 100 2 - 3.517 30 50 2 - 3.518 30 50 2 - 3.5

125 AT / 200 AF

1.25 x 2.6 = 3.25 A

1.25 x 27 = 33.75 A

1.25 x 28 = 35 A1.25 x 10 = 12.5 A1.25 x 10 = 12.5 A

1.25 x 8 = 10 A1.25 x 7.2 = 9 A

1.25 x 9 = 11.25 A

1.25 x 5 = 6.25 A1.25 x 48 = 60 A

AMPERE TRIP (AT)

1.25 x 8 = 10 A1.25 x 28 = 35 A

PPDET

2.5 x 2 = 5 A

1.25 x 10 = 12.5 A1.25 x 10 = 12.5 A1.25 x 12 = 15 A1.25 x 12 = 15 A

1.25 x 2 = 2.5 A

2.5 x 7.2 = 18 A2.5 x 2.6 = 6.5 A

LP DETAILS

2.5 x 28 = 70 A2.5 x 10 = 25 A2.5 x 10 = 25 A

2.5 x 5 = 12.5 A2.5 x 48 = 96 A

2.5 x 10 = 25 A

2.5 x 12 = 30 A2.5 x 12 = 30 A

1.25 x 22 = 27.5 A2.5 x 22 = 55 A2.5 x 27 = 67.5 A

1.73 (230)(0.85)(0.8)32 (1000)

2.5 x 8 = 20 A

2.5 x 8 = 20 A2.5 x 28 = 70 A2.5 x 10 = 25 A

2.5 x 9 = 22.5 A

Meat Cutter Meat Cutter

PPA CKT.NO

AMPERE TRIP, ATNON-

ADJUSTABLETRIP C.B

A.FWire

(m

PPB

Load Per PhaseTotal VAPhaseVolts

PPA

LOAD DESCRIPTION

LP

A B C

1 2

43

5 6

A B

1

3

5


14/23


15/23

2. Lightning Loads:a. Panel as numbered in the Riser Diagramb. Circuit designation number c. number of lightning outlets in each circuitd. Number of switches in each circuite. Number of convenience outletsf. Voltage of circuitg. Fuse rating or trip rating of circuit protective device

3. Other Loads:a. Designation number on planb. description of loadc. Classification of service dutyd. Rating in kilovolt ampere (KVA) or kilowatt (KW)e. Phase loading indicating full load line currentf. Voltage rating

ELECTRICAL ESTIMATION GUIDE:1. Prepare paper, pencils, scale and rulers. Mark papers indicating the panel no., ckt. No and the location of the ckt2. Study plans, drawings and specifications:

2.1 Coordinate with Civil, Mechanical and Architectural Estimators about the following:2.1.1 height between floors2.1.2 drop ceiling and ceiling supports2.1.3 height between finished floors and ceilings2.1.4 major beams and columns thru which conductors may not pass

2.2 Check and make a physical count of the following:2.2.1 lighting fixture - no. of each type of fixture2.2.2 convenience outlet duplex2.2.3 special outlets2.2.4 panel boards - make a complete description of each panel board. The des

a. main breaker ratings or lugs onlyb. no. of branches per ampere tripc. KAIC ratings

2.2.5 Other electrical equipment to be supplied by contractor

2.3 Study carefully the circuit runs and the riser diagram together with the schedule load.3. Determine the approximate length of wire and conduct per circuit.

3.3 Sum up the total length of conduit per size and divide by 150 to get the no. of rolls. Round off3.4 Sum up the total length of wire for each size and divide by 150 to get the no. of rolls. Round o3.5 Set aside the papers and data temporarily.

4. Determine the approximate length of wire and conductor for the panel homerun to the main panel or main distribu

4.4 Wire - multiply the length of conductor by the following constants:a. 2 for two wire single phaseb. 3 for two wire single phase with neutralc. 3 for three wire 3-phased. 4 for three phase, four wires

5. Boxes5.1 Octagonal Boxes - provide one box for each lighting fixture.5.2 Utility box 4" x 2" - provide one box for each switch; duplex outlet or special outlet (small).5.3 Square box 4" - provide one box if the conduits terminating exceed 4 conduits or special big o

6. Fittings6.1 For PVC pipes

6.1.1 couplings - provide 1 coupling for every length plus 1 coupling for ever6.1.2 elbows - provide 1 - 90 degrees elbow for every turn for sizes of 32mm 6.1.3 cement - provide one can for every 10 lengths of conduit.6.1.4 end bells - provide 1 for every terminations.

6.2 For RSC conduits6.2.1 couplings - provide 1 additional coupling for every 5 lengths.6.2.2.elbows - provide one 90 degrees elbow for every 90 degrees turn for size6.2.3 locknut and bushings - provide one pair for every termination.

6.3 For Electrical Metallic Tubing (EMT)6 3 1 Couplings - 1 set screw coupling for every length

4.2 Conduits not embedded in concrete shall be firmly supported and fastened in place every 3.cabinet.

4.1 Conduits - measure the length of the run. Check the shortest possible route and avoid obstadd 5%.

5.4 Square box 4 11/16" - provide one box for 1 inch diameter conduits or for special purpose oor more) terminations.5.5 Pull Boxes - provide one box for every 18 meters per conduits length depending upon t

designated by plans. Check with the designer / consultant about sizes.

4.3 Conduits shall have no more than four (4) 90 degrees bends in any run. When it becomes nbends, an intermediate pull box shall be installed to facilitate pulling of wires and cables.

3.2 For the wire- measure the length between outlet and the length shall be multiplied by the n(length x the number of wires) shall be approximate length of the wire.

2.1.5 other architectural / civil / mechanical / drawings indicating posequipment.

3.1 For the conduit - each ckt measure the length fromthe last outlet to the panel using the scalas per drawings.


16/23

Ju n c t io n Bo x

To Lighting Fixture or Box

Flexible Metallic Condui

Strap

IMC or FlexibleMetallic Conduit

Doubl

Wire Nut Junction / Utility / Square7. Other considerations.

7.1 For lighting fixtures - add 1 meter (multiply by number of wires per conduit) of wire for every

Drop HeightSupport = Ceiling Height +

Pipe** Octagonal Box consideration** PVC if embedded, IMC or Flexible Metallic Condu EMT if exposed Additional 1 meter conside

Floor LightingElevation Fixture

Mounting - As per Architecture Spe

Height Additional 1 meter consideration per wire

7.2 For convenience outletsa. Add 0.8 meter for every c.o. to the length of pipe and 1 meter of wire for ev

Conven ience Outlet

Add 1 meter consideratio

Utility Box** ** For

Add 0.8 meters consideration

Mounting = 0.3 mHeight unle

ElbowConven ience Outle t (Coun ter top)

Add 1 meter consideratio

Utility Box**counter consideration

Add 0.4 meters Mou consideration

Add 0.8 meters consideration

Countertop = As peHeight Spec

floor

b. Add 0.4 meter above the height of counters if the c.o. is above the counte1 meter of wire for every termination.


17/23

7.4 Provide an empty conduit for every spare circuit per panel.7.5 Normally the electronic and communication circuits will be in separate sheets and have an EC7.6 Provide connector for every termination #6 up.

8. Summarize the list of materials as follows:8.1 Conduits - total of each size / type8.2 Fittings - total of each type size8.3 Boxes - total for each type / size8.4 Panels - per panel and lowest canvassed price.8.5 Wires - total length for each wire size8.6 Connectors - (solder less type) total termination of each size for wire size #6 AWG and above8.7 Tape - 1 roll PVC tape for 100 meters of wire plus 1 roll of rubber tape for every 200 meters

9. Costing:9.1 get the unit cost for every item and deduct all discounts.9.2 From the total cost add a 5% to 10% mark-up.

10. Preparation of Bid or Asking Price10.1 Materials Cost

Conduits Fitting BoxesWires and Wiring DevicesLighting FixturesSafety DevicesService Entrance and MainsOthers

10.2 Labor Cost (subject for interpretation)10.2.1 If Materials are importeda. Labor Cost is 20% of sub-total Ab. Supervision is 3% of Sub-total Ac. Mark-up is 1.25% of Sub-total A10.2.2 If the conduits and most materials are locally availablea. Labor cost is 25% to 30% of sub-total Ab. Supervision cost is 4% to 5% of subtotal Ac. Mark-up cost is 2% of subtotal A

10.3 Contingencies - an allowance of 5% to 7% of the total cost of materials and labor.

'- normally 7% to 10% of the cost of materials is the cost of overhead.

10.6 a. the sum of the cost as computed is sections 10.1 to 10.5 is multiplied by 0.03 to get the co b. Add the contractors tax to the sum of sections 10.1 to 10.5 and round-off. This will be yo

11. Concrete encasement / Pipe Chase / Sleeve Sealant DetailsTo compute for concrete encasement (same with block-outs) use the following:11.1 Determine the size of the conduit to be embedded11.2 Determine the length of the conduit to be embedded.11.3 Obtain the volume of concrete to be used. Use the following spacing:

0.05 to 0.075m = Distance between the edge of the conduit to the edge of the 0.05m = Distance between 2 conduit

0.05m Conduit Conduitsize size

0.05m

Concrete Slab

Silicon Sealant or Intume"Specseal" or "Hilti"

Note:Wires and Cables Use Metallic Pipe for all Pip(Typical)

PLAN

10.4 Overhead - this includes the cost of transportation, office staff, tools and equipmenrepresentation and insurance cost of money.

10.5 Permits - shows the plans to the municipal electrical engineer or his assistant and requexigencies.

V of Concrete encasemex A of Blockout

A of Blockout = A ofNo. of conduits)

9.3 For all other materials like ducts, panels, transfer switches, safety switches, starters etc. -discounts) and add 5% mark-up.

A


18/23

WIRING SCHEDULE: 1 PHASE, 2W+G

SET LINE G LINE G METAL PVCS1 15 1 2 1 2 2 15 20S2 20 1 2 1 3.5 3.5 15 20S3 30 1 2 1 5.5 5.5 15 20S4 40 1 2 1 8 5.5 25 25S5 50 1 2 1 14 8 25 32S6 60 1 2 1 22 8 40 40S7 70 1 2 1 22 8 40 40S8 90 1 2 1 30 8 40 40S9 100 1 2 1 38 14 50 50

S10 125 1 2 1 60 22 50 63S11 150 1 2 1 80 22 50 63S12 175 1 2 1 100 30 50 75S13 200 1 2 1 125 30 65 75

WIRING SCHEDULE: 3 PHASE, 3W+G

SET LINE G LINE G METAL PVCT1 15 1 3 1 2 2 15 20T2 20 1 3 1 3.5 3.5 15 20T3 30 1 3 1 5.5 5.5 15 20T4 40 1 3 1 8 5.5 25 25T5 50 1 3 1 14 8 25 32

T6 60 1 3 1 22 8 32 40T7 70 1 3 1 22 8 32 40T8 90 1 3 1 30 8 40 40T9 100 1 3 1 38 14 50 50

T10 125 1 3 1 60 22 50 63T11 150 1 3 1 80 22 65 63T12 175 1 3 1 100 30 65 75T13 200 1 3 1 125 30 80 75T14 225 1 3 1 150 30 80 90T15 250 1 3 1 200 30 90 90T16 300 1 3 1 250 30 100 110T17 350 2 3 1 100 30 65 75T18 400 2 3 1 125 30 80 75T19 500 2 3 1 200 30 90 90T20 600 3 3 1 125 30 80 75T21 800 3 3 1 200 30 90 90T22 1000 4 3 1 200 30 90 90T23 1200 6 3 1 125 30 80 75T24 1600 6 3 1 200 30 90 90T25 2000 8 3 1 200 30 90 90T26 2500 10 3 1 200 30 90 90

C.B. TRIPCONDUCTORS

QUANTITY SIZE (mm2)RACEWAYSIZE (mm)

ITEM NO. C.B. TRIPCONDUCTORS RACEWAY

QUANTITY SIZE (mm2) SIZE (mm)

ITEM NO.


19/23

NEC Table 1

AWG & MCM 75 oC 90 oC 75 oC 90 oC 75 oC 90 oC 75 oC14 20 25 30 3512 25 30 20 25 35 40 3010 35 40 30 35 50 55 408 50 55 40 45 70 80 556 65 75 50 60 95 105 754 85 95 65 75 125 140 1003 100 110 75 85 145 165 1152 115 130 90 100 170 190 1351 130 150 100 115 195 220 155

1/0 150 170 120 135 230 260 1802/0 175 195 135 150 265 300 2103/0 200 225 155 175 310 350 2404/0 230 260 180 205 360 405 280250 255 290 205 230 405 455 315

500 380 430 310 350 620 700 485NEC Table 2

Ambient88-95 oF (31-35 oC) 0.94 0.94 0.94 0.96 0.94 0.96 0.94

97-104 oF (36-40 oC) 0.88 0.91 0.88 0.91 0.88 0.91 0.88NEC Table 3

Conductors 4 - 6 7 - 9 10 - 24 25 - 42 43 or moreFactor 0.80 0.70 0.70* 0.60* 0.50*

* includes effect of a load diversity of 50%NEC Table 4Dimensions and internal areas of Electrical Metallic Tubing (EMT) and Conduit

Sizes (inches) Internal Area m 2

1 1/2 1.610 2.0402 2.067 3.360

2 1/3 2.469 4.7903 3.068 7.380

3 1/2 3.548 9.9004 4.026 12.720

NEC Table 5Dimensions of several rubber and thermoplastic-covered conductors

SizeAWG Approx. Approx. Approx. Approx. Approx. Approx.MCM (inches) Area m 2 (inches) Area m 2 (inches) Area m 2

14 0.2040 0.0327 0.1310 0.0135 0.1050 0.008712 0.2210 0.0384 0.1480 0.0172 0.1220 0.011710 0.2420 0.0460 0.1680 0.0222 0.1530 0.01848 0.3280 0.8450 0.2450 0.0471 0.2180 0.03736 0.3970 0.1238 0.3230 0.0819 0.2570 0.05194 0.4520 0.1605 0.3720 0.1087 0.3280 0.08453 0.4810 0.1817 0.4010 0.1263 0.3560 0.0995

Ampacity Correction Factor

AluminumCopper In RacewaySize

Correction Factor for more than 3 Conductors in raceway or cable

Types RFH-2, RH,RHH

Types TF, THW, TWTypes TFN, THHN,

THWN

In Free Air Copper Alum


20/23

2 0.5130 0.2061 0.4330 0.1473 0.3880 0.11821 0.5880 0.2715 0.5080 0.2027 0.4500 0.1590

1/0 0.6290 0.3107 0.5490 0.2367 0.4910 0.18932/0 0.6750 0.3578 0.5958 0.2781 0.5370 0.22653/0 0.7270 0.4151 0.6470 0.3288 0.5880 0.27154/0 0.7850 0.4840 0.7050 0.3904 0.6460 0.3278

dimensions of RHH and RHWNEC Table 6Maximum no. of conductors in conduits or tubing for most building wire types (TW, XHHW, RHW, RHH, T

1/2 3/4 1 1 1/4 1 1/2 2 2 1/214 9 15 25 44 60 99 14212 7 12 19 35 47 78 11110 5 9 15 26 36 60 858 2 4 7 12 17 28 406 1 3 5 9 13 21 304 1 2 4 7 9 16 223 1 1 3 6 8 13 19

2 1 1 3 5 7 11 161 1 1 3 5 8 12

1/0 1 1 3 4 7 102/0 1 1 2 3 6 83/0 1 1 1 3 5 74/0 1 1 2 4 6250 1 1 1 3 4300 1 1 1 3 4350 1 1 1 2 3500 1 1 1 3

3

Conduit or Tubing (Inch)AWG & MCM


21/23


22/23

, THW)

3 3 1/2 4

171131 17662 84 10847 63 8135 47 6029 39 51

25 33 4318 25 3215 21 2713 17 2211 14 189 12 157 10 126 8 115 7 95 6 8


23/23

EMT/IMC PVCmm mm in

AMPERE AMPERE 15 20 "TRIP FRAME 20 25 3/4"

15 50 25 32 1"20 50 32 40 1-"30 50 40 50 1-"40 50 50 63 2"50 50 65 75 2-"60 100 80 90 3"70 100 90 110 3-"

100 100 100 4125 225150 225175 225200 225225 225250 400300 400350 400400 400500 600600 600700 800800 800

1000 10001200 12001600 16002000 20002500 30003000 30004000 4000

CIRCUITBREAKER

RATING

CONDUIT

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