Question 1: The "Next up size" protection rule is not applicable when sizing over current protection device of transformer secondary conductors.
- True
- False
NEC Reference: NEC 240.4(B)
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Transformer Calculations NEC code Questions
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TimeTransformer Calculations NEC code Questions — Question List
Question 2: What is the primary over current device rating of a 2 wire 480 V to 120 V transformer rated at 1.8 KVA?
- 6 A
- 7 A
- 4 A
- 10 A
NEC Reference: NEC 450.3
Question 3: What is the primary protection required for a 2 wire 480V to 120 V Transformer rated at 900 VA?
- 5 A
- 6 A
- 4 A
- 3 A
NEC Reference: NEC 450.3
Question 4: What is the rating of primary over current protection device required for a 2 wire 480V to 120 V transformer rated at 7KVA?
- 15 A fuse
- 20 A fuse
- 25 Fuse
- 10 A Fuse
NEC Reference: NEC 14.58
Question 5: What is the minimum size secondary conductor is required for a 2 wire 480V to 120 V transformer rated 2.2 KVA with 60<sup>0</sup>C terminals?
- 12 AWG
- 14 AWG
- 8 AWG
- 10 AWG
NEC Reference: NEC 18.33
Question 6: Dry type transformer rated more than ............... are permitted to install in hollow spaces of buildings.
- 50 KVA
- 100 KVA
- 85 KVA
- 75 KVA
NEC Reference: NEC 450.13(A)
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