National Electrical Installation Standards

Standards as High as Your Own

Monday, June 10, 2019


First, I've been reading this column for a for many years and have learned a great deal. Keep up the good work!

Now, I have a control panel in a Class I, Div. II area. The panel is operating at 24 VDC. Everything in the panel is rated for use in a Class I, Div. II area. Does the conduit entering the panel and at the field devices need sealed?

Thanks in advance,

Mike, Columbus, OH


Hey Mike thanks for your question and the compliment. You don't mention what types of equipment are in the panel or what types of field devices are being used and if the devices are still in the Division 2 location. Conduit seals for Class I Division 2 locations are required at enclosures that are required to be explosion proof and at boundaries as stated in 501.15(B)(1) and (B)(2). If the device contacts make and break current the enclosures need to be explosionproof as stated in 501.10(B)(4), with the provided references to other sections, then conduit seals are required at them and at the boundaries.

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