Services, Grounding & BondingQuestion 58 of 120
A dry-type transformer rated 112.5 kVA or less is installed indoors. What is the minimum separation from combustible material unless it is separated by a fire-resistant heat-insulating barrier?
a.3 inches
b.6 inches
c.12 inches
d.18 inches
Explanation
Dry-type transformers of 112.5 kVA or less must be at least 12 inches from combustible material unless separated by a fire-resistant, heat-insulating barrier or unless the unit is completely enclosed except for ventilating openings. The smaller clearances listed belong to other rules such as recessed luminaire and insulation spacing, not to transformer installation.
Law Reference: 2023 NEC §450.21(A)Practice all 120 questions free — no signup required.
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