2-2-5
The secondary amperage available on a 25 kVA transformer at 240 volts is ? . Select one: a.104 A b.144 A c.210 A d.240 A
A. 104A
The coil leads B and C emerge above the oil level in the ? position. Select one: a.crossed b.lower c.right hand d.upper
A. Crossed
The internal transformer lead marked D is always connected to ? in an additive transformer. Select one: a.X1 b.X2 c.X3 d.X4
A. X1
If taps are available on the high voltage coil, the transformer must be ? before changing taps. Select one: a.at full load b.at minimum load c.deenergized d.energized
C. Deenergized
It is the ? responsibility to check the internal connections on a four bushing transformer prior to making the connections externally. Select one: a.line superintendent's b.manufacturer's c.Qualified Electrical Worker's d.shop's
C. Qualified Electrical Worker's
PCBs may be present in distribution transformers manufactured after 1980. Select one: True False
False
Transformer capacity is rated in kilowatts. Select one: True False
False
A distribution transformer may have its secondary coils connected in series or parallel. Select one: True False
True
Alley Cat, Bad Dog" is a good way to remember how the secondary leads are connected when connecting a 120/240 volt transformer for full capacity at 120 volts. Select one: True False
True
On a transformer nameplate, a slash (/) between the secondary numbers means both voltages shown are available. Select one: True False
True
Paralleling the secondary coils is often referred to as stacking the coils. Select one: True False
True
Two secondary bushings are to be used on a transformer when the secondary coils are connected in parallel. Select one: True False
True
With the secondary coils in parallel, the full load current is doubled, but the resultant voltage remains the same as the voltage of one coil. Select one: True False
True
With the secondary coils in series, the full load current remains the same as one coil. Select one: True False
True
On a transformer nameplate, an X between the primary numbers means ? . Select one: a.both voltages are available at the same time b.either voltage is available but not at the same time c.only the higher voltage may be connected wye d.the transformer may only be connected on a delta system
b.either voltage is available but not at the same time
If a Qualified Electrical Worker has installed several 120-volt security lights and needs the total capacity of the transformer, he or she should ? . Select one: a.connect all the lights between X1 and X2 b.connect half of the lights between X1 and X2 and half between X1 and X3 c.connect the coils in parallel d.leave the coils in series and install a larger kVA transformer
c.connect the coils in parallel
A dash (-) between the primary and secondary voltages of a transformer is used to ? . Select one: a.indicate both are available b.indicate one or the other is available c.indicate the full voltage available d.separate the voltages
d.separate the voltages
