Question 31
A 240 V single-phase motor has a full-load current (FLA) of 16 A. If the branch-circuit short-circuit and ground-fault protective device is permitted to be sized at up to 250% of FLA, what is the maximum allowable rating for that device before checking the next standard size?
Question 32
An electric motor nameplate indicates a full-load current of 8 A at 240 V, single-phase. Approximately how much power in watts does the motor use at full load, assuming power factor near 1?
Question 33
A motor nameplate shows a full-load current of 28 A at 480 V three-phase. Approximately what current would you expect at 480 V under locked-rotor (start) conditions if the locked-rotor code suggests 6 times full-load current?
Question 34
A 120 V branch circuit supplies two portable tools. Tool A draws 4 A and Tool B draws 7 A. Assuming no other loads, what is the total current on the branch circuit when both tools operate at the same time?
Question 35
A three-phase motor has a nameplate full-load current of 15 A at 208 V. During normal operation, an electrician measures line currents of about 15 A on each phase. What does this indicate?
Question 36
On a motor nameplate, what does the abbreviation FLA typically indicate?
Question 37
A 1,500 W portable heater is plugged into a 120 V, 15 A branch circuit already supplying a 2 A lighting load. Approximately what total current will the circuit carry?
Question 38
A 10 hp, 230 V, three-phase motor has a nameplate full-load current of 28 A. Which factor is most important in selecting the branch-circuit conductor ampacity for this motor circuit?
Question 39
Which copper conductor size is typically acceptable for a 20 A general-purpose branch circuit in a US dwelling unit, assuming standard conditions?
Question 40
A lighting branch circuit supplies ten 60 W lamps at 120 V. Approximately how much current does the circuit carry when all lamps are on?
Question 41
A 20 A, 120 V general-purpose branch circuit is loaded to 14 A by existing receptacles. Approximately how much additional current can be added while staying at or below 80% of the circuit rating for continuous load?
Question 42
A motor is 85% efficient and draws 10 kW of input power. What is the output power in kW?
Question 43
A 3-phase motor nameplate lists the Full Load Amps (FLA) as 24A. What is the minimum ampacity rating required for the branch circuit conductors?
