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Posted By: andy19 3- 15kw heating units - 10/18/01 04:02 PM
I HAVE A 200 AMP 120/240V 1PHASE M/L/O LOAD CENTER PANEL IN A MODULAR SCHOOL BUILDING
THAT THE MANUFACTURER INSTALLED 3 -15KW 240V
1 PHASE IN. TOTAL LOAD OF 198 AMPS WITH BLOWER MOTORS. I'M PLANNING ON FEEDING THIS SUB PANEL WITH A 200 AMP FUSE DISCONNECT. anything IN THE NEC THAT SAYS I CAN'T DO THIS? I'VE ASKED SERVERAL PEOPLE AND THEY SAID I COULDN'T BUT COULDN'T GIVE ME A CODE REFERENCE.
THANKS FOR YOUR HELP
ANDY

[This message has been edited by andy19 (edited 10-18-2001).]
Posted By: Tom Re: 3- 15kw heating units - 10/20/01 12:40 AM
Andy,

The best I can say is "maybe."

See 220-15, the exception seems to offer some wiggle room. If all units will be on at the same time, what about the lights & receptacle load, are they on another feeder? Seems to me that there is not enough capacity. To apply the exception, you'll need permission from the AHJ.

Tom
Posted By: bordew Re: 3- 15kw heating units - 10/20/01 07:08 PM
Andy:
Wouldnt this be considered a continuous load?
210.20(A). So if your load is 198 amps with that kind of load the conductors could also be used as heaters (?)
Just by that the rating should be 247 amps or 125% of the load + the non-continuous load. Also art. 424.3(B) Branch circuits, fixed electric space heating equipment, shall be rated at 125 % of total load and motors.
I would think you need a bigger panel.
Posted By: electure Re: 3- 15kw heating units - 10/21/01 01:10 AM
I think I'd contact whoever it was that supplied this piece of "art", and have them give you something that is Code compliant.
If it's going in a school, the school district should at least have enough clout to get something safe from them.
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