Question

A datacenter technician encounters a power receptacle labeled NEMA L5-30. Which of the following powers is this socket rated for?

a) 120V, 20A
b) 240V, 15A
c) 125V, 30A
d) 250V, 20A

Answer 1

The socket labeled NEMA L5-30 is rated for 125V, 30A. The combination of an 1800-W toaster, a 1400-W electric frying pan, and a 75-W lamp on the same 15-A circuit will draw 27.295 A in total, likely causing a 15-A fuse to blow.

Step-by-step explanation:

The power receptacle labeled NEMA L5-30 is rated for 125V, 30A. Now, to address the other parts of the given scenarios:

1. An 1800-W toaster, a 1400-W electric frying pan, and a 75-W lamp are plugged into a 15-A, 120-V circuit. The current drawn by each device can be calculated using the formula current (I) = power (P) / voltage (V). Thus, the currents are 15 A, 11.67 A, and 0.625 A, respectively.
2. If you plug all three into the same outlet, the combined current drawn will be the sum of the individual currents, which totals 27.295 A. This would exceed the capacity of the 15-A fuse, likely causing it to blow.
3. The voltage and frequency of power outlets vary by country, and hence household devices are designed to operate within these specifications. For example, in the United States, the common voltage is 120 V with a frequency of 60 Hz.
4. For the cassette recorder transforming 120 V to 12.0 V, if we assume ideal conditions, the power input equals the power output. Thus, with a maximum current output of 200 mA (0.2 A) at 12.0 V, the power is 2.4 W. Using P = IV, the current input at 120 V would be 0.02 A.