Quiz

Transformers

1. Potential transformers installed indoors or enclosed must be protected with primary fuses.
(a) true
(b) false


2. A transformer field connected as an autotransformer is not required to be identified for use at elevated voltages.
(a) true
(b) false


3. Transformers rated at 10 kVA are not required to have the impedance listed on the nameplate.
(a) true
(b) false


4. Dry-type transformers 1000 volts, nominal, or less, located in the open on walls, columns, or structures, are required to be readily accessible.
(a) true
(b) false


5. A 2020 Code change now states that transformer top surfaces that are horizontal and readily accessible shall be marked to prohibit storage of combustible products on them.
(a) true
(b) false


6. Each autotransformer 1000 volts, nominal, or less shall be protected by an individual overcurrent device installed in series with each ungrounded input conductor. 
(a) true
(b) false





Answers:
1. (a) Ref: 450.3(C)
2. (b) Ref: 450.4(B) 
3. (a) Ref: 450.11(A)(5)   
4. (b) Ref: 450.13(A)
5. (b) Ref: 450.9
6. (a) Ref: 450.3(A)