225.2 worksheet

When properly connected to deliver 208 volts from a 190-volt supply circuit (affected by voltage drop), a _____ kVA (standard size) 120 x 240 - 12/24-V transformer can operate a 29 amp load without being overloaded

0.75

A _____ kVA 240 x 480 - 24/48-V transformer that is connected to a 277-volt circuit should be used to operate a 230-volt 1-ph motor that draws 25 amps

1

Without being overloaded, a 0.5 kVA 120 x 240 - 12/24-V transformer can carry a maximum of _____ amps at 12 volts

41.6

The circuit you have available to supply a 240-V, 150 A load is 208 volts. The rating for a B-B transformer that can operate the load at its rated voltage is _____ kVA

5.0

Which connection diagram, shown in Figure 224.108, should be used where the Supply Circuit is from a 1-pole breaker 120/240-volt, 3-ph, 4-W panelboard? The load is rated to operate at 12 volts. The transformer is a 120 x 240 -- 12/24 volt

I

Which of the drawings, shown in Figure 224.101, is connected as an autotransformer?

I only

Which connection diagram, shown in Figure 224.108, should be used where the Supply Circuit is from a 2-pole breaker 120/240-volt, 3-ph, 4-W panelboard? the load is rated to operate at 12 volts. The transformer is a 120 x 240 -- 12/24 volt

II

When supply voltage is to be changed +- 15%, a buck-boost transformer is connected as _____ to deliver the proper voltage to the load

an autotransformer

Buck-boost transformers are available with secondary windings that are rated to deliver voltages of _____

any of these 16, 24, 48, 12

To produce an output of 12 volts, a 120 x 240-volt primary - 12/24 -volt secondary transformer is connected as a(n) _____

insulating transformer

Where the circuit voltage is 208 volts, a buck-boost transformer can be used to operate a load that is rated to operate at 240 volts

true

Where the circuit voltage is 240 volts, a buck-boost transformer can be used to operate a load that is rated to operate at 12 volts

true