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Self-Test 1 Q&A 4-3
Self-Test Questions Volume 1
Question | Answer |
---|---|
List the general categories of electrical loads found in buildings | Mainly, lighting with some motor operation, fairly heavy lighting with moderate requirement for power equipment, and mostly power equipment with a small lighting load. |
What type of electrical system would be needed to service a small building with lights only? | Two-wire, single-phase system. |
What type of wiring system is needed in a residence where an electric range and dryer are installed? | Three-wire, single-phase system. |
A pumphouse is being wired to provide power for three heavy-duty pumps. The pumps operate unattended, starting and stopping automatically. What type of electrical system would this pumphouse most likely have? | Three-phase, three-wire. |
A building is provided with electrical power to operate several pieces of equipment using 208volt motors ranging in size from 3 to 10 horsepower. Lighting is also a large requirement. What type of electrical system is needed in this building? | Three-phase, four-wire system. |
A building is provided power with a three-phase, four-wire system with a delta transformer hookup. Why can only two-phase conductors be used to provide power for the lighting system? | Because the voltage from the third-phase conductor to the neutral is much higher than 120 volts. |
Explain the delta wild leg requirements in regard to color coding and phase relationship on panelboards. | The wild leg is color-coded orange whenever it is in the same enclosure as the neutral. The phase relationship on panelboards always has the wild leg in the center, or "B" position. |