Quiz 4

Two rows of fluorescent lamps are installed in an office on the same branch circuit, with each row drawing 12.5 amperes. The source voltage is 277 volts, and the line resistance is 0.5 Ω. The wire used has a constant (k) of 12.6. If the load is 130 feet from the source, what size wire would you need to install for this circuit to meet the recommendations of the NEC for acceptable voltage drop on a branch circuit? (Assume 75°C wire)

10 AWG

Two rows of fluorescent lamps are installed in an office on the same branch circuit, with each row drawing 12.5 amperes. The source voltage is 277 volts, and the line resistance is 0.5 ?. The wire used has a constant (k) of 12.6. If the load is 129 feet from the source, what is the specific wire size used in this installation? (Assume 75°C wire.)

12 AWG

What is the percentage of voltage drop if you have 235 volts at a load fed from a 240-volt source?

2.1%

Two rows of fluorescent lamps are installed in an office on the same branch circuit, with each row drawing 12.5 amperes. The source voltage is 277 volts, and the line resistance is 0.5 Ω. The wire used has a constant (k) of 12.6. What is the voltage at the load?

264.5 V

The NEC recommends that voltage drops on branch circuits not exceeding _____ at the farthest outlet of power, for heating or lighting loads, will provide for reasonable efficiency of operation.

3%

Two rows of fluorescent lamps are installed in an office on the same branch circuit, with each row drawing 12.5 amperes. The source voltage is 277 volts, and the line resistance is 0.5 Ω. The wire used has a constant (k) of 12.6. What is the percentage of voltage drop?

4.5%

If a generator voltage is 240 volts, and the load voltage is 235 volts, how much voltage is dropped on the line?

5 V

Two rows of fluorescent lamps are installed in an office on the same branch circuit, with each row drawing 12.5 amperes. The source voltage is 277 volts, and the line resistance is 0.5 Ω. The wire used has a constant (k) of 12.6. The voltage drop will be within the recommendation of the NEC.

False

How could you correct a voltage drop problem involving two rows of fluorescent fixtures fed from the same circuit in a practical manner?

Install larger wire or put each row of fixtures on a separate circuit.

Conductor resistance causes a(n) _____ between the voltage source and the connected load.

decrease in current, power loss, and voltage drop

Loads are normally connected in ? with the source, and the resistance of the line is in ? with the source.

parallel / series