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INDUSTRIAL TRAINING INSTITUTE BHOPAL
LESSON PLAN
NAME:- SMT. KAMINI SINGH TRADE : - ELECTRICIAN SEMESTER : 2
TIME:- DATE: - UNIT/ WEEK NO: 27.5
SUBJECT: Estimation of load, cable size, bill of material and cost.
OBJECTIVE : At the end of this lesson you shall be able to -
1. Calculate the full load current and size of cables.
2. Estimate the cost for workshop wiring.
3. Tabulate the material required.
AIDS : White board, marker, duster , charts.
REVIEW: Study the consumer’s requirement of light, fan and power point in workshop. Divide the load
equally in 3-phase while doing so, as a requirement.
MOTIVATION: Refer to the position of accessories diagram and also the load division, then draw the
layout, diagram and the wiring diagram to be drawn.
DEVELOPMENT /PRSENTATION
TOPICS INFORMATION POINTS SPOT HINTS
1. Estimation A sample requirement is given for workshop:
of load :- 1. One 5Hp, 415 volt 3 phase motor.
2. One 3Hp, 415volt 3phase motor.
3. One ½ Hp, 240 volt 1 phase motor.
4. One 1 Hp, 415 volt 3 phase motor.
2. Calculation Assuming the motor efficiency to be 85% and
for the size of the power factor to e 0.8 for all the motors
and the supply voltage is 400v.
cable :-
FL current of 5 Hp motor = 5x735.5 = 7.8 A
1.732x400x0.85x0.8
SNo. Motor FL current Starting Recomme
nded
IL in Amp current
01. 5 Hp 7.8 A 15.6 2.0mm Cu
motor OR 2.5
mm Al
3. Bill of SNo. Accessories / machinery & Qty.
materials :- Equipment
01. 3-Phase squirrel cage induction motor- 01No.
5Hp 415v with and all Accessories
02. 3- Phase slip ring induction motor - 01No.
3 Hp 415 v with starter and all accessories
03. Single phase capacitor start and capacitor-01No.
run motor ½ Hp 240v
04. 3-Phase squirrel cage 1 Hp 415v - 01No.
induction motor with starter and all accessories
05. Ceiling fan -- 05 Nos.
06. Tube light fitting complete --10 Nos.
07. Other set 250v 40w -- As required
Total cost of wiring = cost of the accessories + cost
4. Cost of of cable + cost of conduit + cost of hardware items
wiring:- + labour cost.
QUESTION: - 1. How do you estimate an electrical plan?
2. How much does it cost to wire a 1700 sq foot house?
SUMMARY: - In electrical workshop the main switch, motor switch and starters are to be
mounted at a height of not more than 1.5m from the ground level and the height of horizontal
run from ground level will be 2.5 m.
ASSIGNMENT:-1. How do you calculated electrical load in a workshop?
REFERENCE:- Nimi book , Arihant publication , Asian publishers
NEXT LESSON:- Inspection and testing of wiring installations.
Signature of T.O. Signature of T.S.
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