Question 8073 of 938 · Maryland Journeyperson Electrician Exam
What is the general fire resistance rating required for transformer vault walls and roofs?
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Correct answer to question 8073
- D: 3 hours
Explanation
Section 450.42 generally requires walls and roofs of transformer vaults to have adequate structural strength and a minimum fire resistance of 3 hours. Where vaults are protected by automatic sprinklers or similar systems, 1 hour construction is permitted.
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