2-2-13 Conducting Transformer Load Checks (A)
A 15-kVA single-phase distribution transformer shows 75 amperes on X1 and 60 amperes on X3. Voltage is 120 volts from each secondary bushing to the neutral. The transformer has exactly ? of load.
16.2kVA
An engineer wants an accurate spot load check on a single-phase service. The A conductor has 115 volts and 95 amperes, and the B conductor has 113 volts at 78 amperes. There is ? being pulled off the transformer.
19.7 kva
According to the rule of thumb in the reference book, at 120 volts single-phase, there are ? available from a 25-kilovolt-ampere transformer.
207.5A
The tap setting on the side of the maximeter should be set to ? if placed on a 25-kVA single-phase transformer.
40/1
Overload peaks of ? do not affect a transformer.
5 min
Total phase current times line to neutral voltage equals kilovolt-ampere.
False
Twenty- to thirty-minute overload peaks are of no concern when conducting a load test.
False
Maximeters record the ? during the time of the test.
Highest load
A balanced load on a transformer is when ? .
both phase to neutral leads have the same load
When a maximeter is clamped around an energized conductor, never ? .
change taps on the meter
A 15-kilovolt-ampere transformer is checked and is carrying 19.5 kilovolt-amperes; it should be reported as overloaded.
true
A load test taken with a clip-on ammeter and a multimeter will indicate if a transformer is overloaded at the time of the test.
true
A single-phase transformer should have a maximeter placed on each secondary lead from the transformer.
true
Since a single-phase distribution transformer has two secondary coils, it is possible for only one coil to be overloaded.
true
The red indicator needle on a maximeter indicates the load at the time of the reading.
true