Services & DistributionQuestion 50 of 521
Why must ventilating openings of a dry-type transformer be kept clear of walls and obstructions?
a.To reduce audible noise
b.To meet grounding rules
c.To dissipate heat and prevent overheating
d.To improve power factor
Explanation
Per 450.9, transformer ventilation must not be blocked so that heat generated by losses can dissipate and the transformer does not overheat. Noise, grounding, and power factor are governed by other rules and are not the purpose of the ventilation clearance.
Law Reference: 2023 NEC §450.9Practice all 521 questions free — no signup required.
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