National Electrical Installation Standards

Standards as High as Your Own

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Tuesday, September 26, 2017

Question:

I cannot find anything about working space around large motor junction boxes. I have a 2500 hp motor at 4160v. The company that I am installing this for is giving me 22" in front of the bolted down face plate to the junction box. It has a wall 22" from the front and I keep trying to explain to no avail. Is the code a little clearer on this, other than 110.26?

Tee Raynes

A

Answer:

Hey Tee thanks for your question. Motors must be located so that maintenance can readily accomplished as stated in 430.14 but it does not specifically include details or dimensions. Based on your motor voltage 110.32 requires sufficient space for ready and safe operation and maintenance. Equipment that is likely to require examination, adjustment, servicing or maintenance - while energized, must have the work space dimensions included in Table 110.34(A). This wording is often subject to different interpretations by AHJ's and others and does need some judgment.

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