Question

1. The amount of available fault current at the service depends upon the ______.

1. Method of banding
2. Method of grounding
3. Size and impendence of the service transformer
4. Ampere rating of the overcurrent protection device

2. The line current for a 240/120 volt, 3-phrase system, if each phase is balanced with a 3,000-VA load and the total load is 9,000 VA, is ______ amperes.

1. 12.5
2. 15
3. 21.65
4. 37.5

3. Given: A dwelling unit has 3,000 sq.ft. of habitable space with laundry facilities and bathrooms, 600 sq.ft. of garage and 1,000 sq.ft. of unfurnished space that is adaptable to future use when calculating the service-conductor size for this dwelling unit using the standard calculation method, the minimum demand is ______ VA.

1. 6,150
2. 7,725
3. 12,000
4. 16,500

4. Given: A commercial building with a 3 wire, single-phase 120/240 volt service has a total load of 35,000 VA after all demand factors have been considered. The minimum size THNN copper conductions required for the undergrounded service conductors _____ AWG.

1. 3
2. 1/0
3. 2/0
4. 3/0

5. Remote- Control Circuit Conductions for safety control equipment shall be physically protected for which of the following?

1. Network-interface units
2. Room Thermostat devices
3. Water-temperature-regulation devices
4. Equipment that has the potential to create a life hazard upon failure

6. Blank
7. The required depth of the working clearance for a 120/240 volt, single family dwelling service when grounded parts are opposite, the service is _____.

1. 2tf-6in
2. 3ft-0in
3. 3ft-6in
4. 4ft-0ft

8. The service conductors are permitted to be connected to the service disconnect by any of the following means except _____.

1. Soldier type lugs
2. Clamp-on type connectors
3. Pressure-wash type connectors
4. Set-screw type pressure connectors

9. What required clearance, in feet, must conductors over a roof maintain beyond the edge of a roof (assume no exceptions apply.)

1. 1
2. 2
3. 3
4. 4

10. Given: overhead service conductors of a 120/240 volt service are run above a roof with a slope of 6:12 and the roof is not an over-hanging roof. The minimum required clearance from the roof to the overhead service conductors that are above the roof is _____ ft.

1. 3
2. 4.5
3. 6
4. 8

11. Is a disconnecting means required for a structure that is aid accessory building to a single-family dwelling?

1. No
2. yes, and it shall be on the exterior of the structure
3. Yes, and it shall be on the interior of the structure
4. yes, and it is permitted to be on either the interior or exterior of the structure

12. A main bonding jumper shall be _____.

1. Removed
2. Factory-installed
3. A sheet-metal screw
4. Corrosion-resistant material

13. The continuity of a grounded conductor installed in a metallic enclosure shall _____.

1. Not be left or less
2. Have overcurrent protected overcurrent protection
3. be terminated with a sheet metal screw
4. not be dependent on a connection to a metallic enclosure

14. Given: on a 480/240-volt step down transformers, the primary current is 200 amperes. The approximate secondary current is _____.

1. 100
2. 200
3. 300
4. 400

15. What is a secondary current of a single-phase, step-up transformer if the primary voltage is 120 volts, the secondary voltage is 600 volts, and the primary current is 10 amperes? (assume no transformer impendence)

1. 2 amperes
2. 5 amperes
3. 10 ampere
4. 50 amperes

Answer 1

The amount of available fault current at the service depends upon the

Ampere rating of the overcurrent protection device

6 for 240/120v 3-4 System power: 3000VA 300 o = 12-5A I- (A is consect 240 option @ Givon 480/240 step down transformer primary arsent - 2004 In transformer power 166807 (200) = 1346) (15) Is = 4004 option ② is correct Vp Ip= KI is constant 0 Given vp = 1201 = 120V V3 = 600V Is = ? Ip = 10 A Ve Tp=VIS =) (1203210) = C6oo) (1) Is=2A1 option ② is correct. e scanned with CamScanner