Module 1: Branch Circuit
Lesson 1: Lighting Branch Circuit
Activity/Exercise no. M1-L1
1. Total wattage or power of the lighting circuit.
Ans. 8 outlets × 100 = 800 watts
2. Total circuit load current.
Ans. 800 watts ÷ 230 volts = 3.48 amperes
3. Wire size using THWN
Ans. No.14 TW copper wire
4. Size of conduit pipe
Ans. 13mm diameter conduit pipe
5. Size or ampacity of fuse or breaker protective device
Ans. 15 amperes fuse
Lesson 2: Convenience Outlet/ Appliance Brance Circuit
Activity/Exercise no. M1-L2
1. Total wattage or power of the convenience outlet circuit.
Ans. 12 x 180 watts per outlet = 2,160 watts
2. Total circuit load current.
Ans. 2,160 watts / 230 volts = 9.39 amperes
3. Wire size using THWN.
Ans. No.12 TW copper wire
4. Size of conduit pipe
Ans. 13 mm conduit pipe
5. Size or ampacity of fuse or breaker protective device
Ans. 20 amperes fuse
Lesson 3: Special Purpose Outlet Branch Circuit
Activity/Exercise no. M1-L3
1. Total wattage or power of the convenience outlet circuit.
Ans. 1 - unit electric stove at 1.1 kw = 1,100 watts + 1 - unit water heater at 2.5 kw = 2,500 watts = 3600
watts
2. Total circuit load current.
Ans. 3,600 watts / 230 volts = 15.65 amperes
3. Wire size using THWN.
Ans. No.12 AWG TW copper wire
4. Size of conduit pipe
Ans. 13 mm diameter conduit pipe
5. Size or ampacity of fuse or breaker protective device
Ans. 20 amperes fuse rating
Lesson 4: Service Entrance Computation
Activity/Exercise no. M1-L4
1. Total wattage or power of circuit 1-3
Ans. Total current load = Total connected load / voltage rating
= (800 W + 2,160 W + 3,600 W) / 230 V
= 28.52 amperes
2. Total load current of circuit 1-3
Ans. 28.52 x .80 = 22.8 amperes
M
3. Wire size using THWN.
Ans. No.8 TW copper wire
60 A
4. Size of conduit pipe
Ans. 20 mm diameter conduit pipe
15 A 20 A
5. Size or ampacity of fuse or breaker
Ans. 40 amperes fuse
6. Make a schedule of load for your circuit 1-3
Ans. Circuit 1 - 3.48 amperes
Circuit 2 - 9.39 amperes
Circuit 3 - 15.65 amperes
Total - 28.52 amperes
7. Make a one-line diagram from service entrance to branch circuit.
Ans.
Service Entrance
To Light Outlet To C.O.
Spare Kit. C.O.
Module 2: Electrical Distribution
Lesson 1: Fundamentals of Distribution System
Activity/Exercise no. 1 M2-L1
1. Which of the three distribution systems used by the utility company illustrated below offers the
greatest continuity of service and which is the most economical to build and maintain?
Greatest Continuity: C.
Most Economical: A.
2. The piece of electrical equipment used to step up or step down the voltages is a Transformer.
3. When the electric company generates electricity, it usually reduces the voltage before it enters the
transmission system because it is safer and more economical to move lower voltages to the points of
utilization.
TRUE FALSE
4. A transformer that makes the voltage lower is called a Step down transformer.
Activity/Exercise no.2 M2-L1
1. A one-line diagram shows the components, electrical relationships and connections with a single-
phase circuit only, thus the name one-line diagram.
TRUE FALSE
2. In the one-line diagram illustrated below, the disconnect switch shown would have to have a voltage
rating of how many volts, assuming you have no additional information?
Ans. 5 kv
3. Next to the electrical symbols illustrated below, enter the name of the electrical component it
represents.
a. Transformer
b. Removable Circuit Breaker
c. Fuse
d. Normally Closed Contact
e. Low Voltage Motor Control
f. Disconnect switch
Activity/Exercise no.3 M2-L1
1. The most vulnerable part of an electrical circuit to overcurrent conditions is the
Ans. Conductor (Cable) Insulation
2. List the three types of overcurrent conditions.
a. Overload
b. Short Circuit
c. Ground fault
3. Which overcurrent condition usually has the smallest magnitude of current?
Ans. Ground fault
4. In your own words explain the function of the NEC.
Ans. National Electric Code a set of electrical installation standards applicable throughout the U.S. and
published by the National Fire Protection Association. The NEC works with UL requirements and usually
carries mandatory compliance.
5. Safety labels quickly alert an individual to the degree of a potential hazard or problem by using single
enlarged, word like:
List two others
Ans. Danger, Caution
