1What is the voltage between any two hot lines of a 230 volt Delta power supply?
230V
2What is the voltage between a hot line and ground on a 240 volt Delta power supply?
No usable voltage
3What is the voltage between any two hot lines of a 230 volt Grounded Delta power supply?
230V
4Draw a diagram of a 230 volt Grounded Delta power supply. Label all of the voltages and the wild leg.
See page 3-9
5What is the wild leg?
Leg with higher than 120 volt components in the circuit
6What danger is presented by a wild leg?
High voltage that will damage 120 volt components in the circuit?
7What is the voltage between either of the non wild leg hot lines and neutral in a 230-volt Grounded Delta system?
115V
8What is the voltage between the wild leg and neutral or ground on a 240-volt power supply?
209V
9How do you determine which hot line is the wild leg in a 250 volt Grounded Delta power supply?
THe one that does not measure 120 volts or neutral or ground
10What danger is there when replacing a three phase circuit breaker in a 230 volt Grounded Delta power supply?
Crossing the hot lines and supplying the wild leg to the wrong terminal in the unit.
11Why is a "WYE" power supply so versatile?
Can get 120V and 208V as well as single and three phase.
12What is the voltage between any two hot lines in a 208 volt WYE power supply?
208V
13What is the voltage between any hot line and neutral or ground in a 208 volt WYE power supply?
120V
14What is the voltage from any hot line to ground or neutral, on a 480 volt WYE power supply?
277V
15If you had a commercial building and you had a three phase supply to your building, how many different incoming power supplies would you need if the incoming three-phase supply was three phase Delta?
2
16If you had a commercial building and you had a three phase supply to your building, how many different incoming power supplies would you need if the incoming three-phase supply was three phase Grounded Delta?
1
17If you had a commercial building and you had a three phase supply to your building, how many different incoming power supplies would you need if the incoming three-phase supply was three phase WYE 208V
1