When a motor that is listed Cl 1 Div 1 Gr C&D that is TEFC and the wiring compartment is factory sealed between the motor and the junction box, is an external seal required on the conduit leading up to the motor J-box? It seems as though the rule would apply to the size of the J-box and conduit. Any thoughts on this?
Sealing motors in Class 1 Div 1
- Thread starter Bob5K
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- Mission Viejo, CA
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- Professional Electrical Engineer
Assuming the motor is actually installed in a Class I, Division 1 location and there are no other direct considerations, you are basically correct. Even the terminal box size is not really a direct consideration only the “entry… metric designator" is truly relevant as you have described the motor construction. See [NEC 2005]501.15(A)(1)(2).
weressl
Esteemed Member
rbalex said:
We had a long drawn-out discussion on this topic several years ago. Verify with the manufacturer if the seal is an XP rated seal between the stator enclosure and the termination box. If the answer is affirmative then you don't even have to look for the CLIXON thermal switch that is often part of the motor thermal rating and required to be wired into the control circuit - so it could be a source of ignition - and not specifically listed as XP itself.
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