Disconnect needed for heat trace controller?

[charlie b]

Are the controllers for piping heat trace systems typically connected plug & cord or hard wired? If hard wired, is there a requirement for a local disconnect? I am inclined to think not, but I am not sure where to look in the NEC. I would not classify this as an industrial control panel, as addressed in 409. I should not have called it an appliance either, as it does not appear to meet the article 100 defintion. But article 422.50 makes me wonder. Any thoughts?

 

[nhee2]

427.55 provides info on pipeline/vessel heating disconnecting means - and looks like it would apply to resistance heating elements (Section III in Article 427). I have typically seen hardwired by 427.55(B) allows for cord-and-plug if less than 150V/20A.

 

[charlie b]

Thank you. I had not previously encountered article 427, and there is no tab in my code book for that article, so I didn't know it existed.