Question

A 100 kVA dry type transformer with a 4,160 volt primary is set up indoors in an area where combustible materials are stored. The transformer MUST be separated from combustible material by a smallest of:

1. 6 in
2. 12 in
3. 18 in
4. 24 in

Answer 1

The transformer must be separated from combustible material by a minimum distance of 18 inches.

Step-by-step explanation:

The National Electric Code (NEC) specifies the minimum separation distance between a dry type transformer and combustible material to prevent the risk of fire. According to NEC, a 100 kVA dry type transformer with a 4,160 volt primary should be separated from combustible material by a minimum distance of 18 inches (Option 3).