EEP Unit 7
Overcurrent protection for the secondary of a transformer rated 1,000V or less having a secondary current rating of 9A or more must be set at not more than _____ percent of the secondary current rating.
125
The primary overcurrent protection for a transformer rated 1,000V, nominal, or less, having a primary current rating of 9A or more must be set at not more than _____ percent of the primary current when using primary only overcurrent protection.
125
What size secondary conductor can be used for a three-phase, 480V transformer, where the secondary overcurrent protection is sized at 110A?
2 AWG
A 45 kVA, 480V primary to 120/208V secondary, three-phase transformer with a 175A secondary overcurrent device will require at least _____ secondary conductors (the secondary conductors are 10 ft long).
2/0 AWG
What size secondary conductor can be used for a three-phase, 480V transformer, where the secondary overcurrent protection is sized at 175A?
2/0 AWG
The size of the grounding electrode conductor for a single separately derived system must not be smaller than that identified in _____, based on the area of the largest derived ungrounded supply conductor.
250.66
What's the maximum primary overcurrent device rating for a 0.50 kVA, single-phase, 240V transformer?
3 A
A 75 kVA, 480V primary to 120/208V secondary, three-phase transformer with a 300A secondary overcurrent device will require at least _____ secondary conductors (the secondary conductors are 10 ft long).
300 kcmil
In an alternating-current system, the size of the grounding electrode conductor to a concrete-encased electrode isn't required to be larger than a(an) _____ copper conductor.
4 AWG
What's the maximum primary overcurrent device rating for a 2.50 kVA, 480V, single-phase transformer?
6 A
A 45 kVA, 480V primary to 120/208V secondary, three-phase transformer with a 70A primary overcurrent device will require at least _____ primary conductors with terminals rated 75°C.
6 AWG
A 75 kVA, 480V primary to 120/208V secondary, three-phase transformer with a 125A primary overcurrent device will require at least _____ primary conductors with terminals rated 75°C.
6 AWG
What size secondary conductor can be used for a three-phase, 480V transformer, where the secondary overcurrent protection is sized at 50A with terminals rated 75°C?
8 AWG
What's the maximum primary overcurrent device rating for a 25 kVA continuously loaded, three-phase, 240V transformer?
80 A
The connection of the system bonding jumper for a separately derived system must be made _____ on the separately derived system from the source to the first system disconnecting means or overcurrent device.
At any single point
The grounding electrode conductor for a single separately derived system is used to connect the grounded conductor of the derived system to the system bonding jumper.
False