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9 Cards in this Set
- Front
- Back
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26.) other than class two conductors lighting systems operating at 24 V will have their transformer secondary current limited to a largest of? |
3. 25 amps 411.3 |
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A transformer has a 75 kVA rating and is 460 V three phase with an efficiency of 90° what’s the impasse is it in ampacity necessary for the primary wire? |
104.6 amps (75*1000)/ (1.732*460*90) |
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28.) A jewelry store has two 15 foot show windows one on either side of the entranceway what’s the smallest number of receptacles necessary to service these windows? |
2 per window 220.43 / 220.14(G) |
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29.) When using threaded fittings in a class one division one area a minimum of how many threads must be engaged? |
5 threads 500.8 (E)(1) |
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30.) A three phase motor controller is also the disconnect it is required to open |
All 3 phases |
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31.) 480/ 277 V feeder utilized at 400 A is run from building one of the building 2 the branch circuits originate in the second building and serve mostly motor loads in the building what’s the smaller size grounding wire allowed to run in the second building |
3 awg Table 250.122 |
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32.) A non-metallic sheathed cable of 60° rated wires feeds a panel that needs grounding it is utilized at 60 A what size copper equipment grounding wire is required?
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#10 Table 250.122 |
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33.) what’s the Ampacity of three 1 gauge THW copper wires in a race way at an ambient temperature of 86° |
130 amps Table 310.15 (b)(16) then ambient correction |
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34.) Hey 600 V 20 amp transformer will have an individual overcurrent device on the primary side rated at a largest of how many amps no overcurrent protection is utilized on the secondary side of the transformer |
25 amps Table 450.3 |
