Achirb2
Member
- Location
- Milwaukee WI
I am looking at temperature control units for work. These are pretty much heaters that heat and circulate water or oil through a plastic injection mold or other process to maintain a specific temperature.
For a 480V 60KW heater I calculate this load at just over 72A. I would expect, per Article 425, that this heater be subdivided into two branches with fusing on both branches. The vendor states that fusing isn't required because this is more of an appliance?! Am I crazy? They want me to specify and provide a fused disconnect for this equipment and claim that the overcurrent protection for the unit comes from the fused disconnect I provide. I believe they are leaning into the casters on the bottom of the unit as the unit not being "fixed"
The thing I question about my own knowledge is that I'm finding that for these TCUs, on the low price range, it seems like this is common practice... Some of these manufacturers charge extra for a NFPA 79 compliant panel, let alone what I consider a NEC violation.
Thank you so much for any input.
When reviewing Article 425 I read this in the 2017 code:
For a 480V 60KW heater I calculate this load at just over 72A. I would expect, per Article 425, that this heater be subdivided into two branches with fusing on both branches. The vendor states that fusing isn't required because this is more of an appliance?! Am I crazy? They want me to specify and provide a fused disconnect for this equipment and claim that the overcurrent protection for the unit comes from the fused disconnect I provide. I believe they are leaning into the casters on the bottom of the unit as the unit not being "fixed"
The thing I question about my own knowledge is that I'm finding that for these TCUs, on the low price range, it seems like this is common practice... Some of these manufacturers charge extra for a NFPA 79 compliant panel, let alone what I consider a NEC violation.
Thank you so much for any input.
When reviewing Article 425 I read this in the 2017 code:
Code:
Resistance-type heating elements in
fixed industrial process heating equipment shall be protected
at not more than 60 amperes. Equipment rated more than 48
amperes and employing such elements shall have the heating
elements subdivided, and each subdivided load shall not
exceed 48 amperes. Where a subdivided load is less than 48
amperes, the rating of the supplementary overcurrent protec‐
tive device shall comply with 425.3(B).