Have a 1200A 480V service board in dedicated electrical room. Would like to tap bus and extend conductors via conduit out top of said board across ceiling and terminate into fused SE rated disconnect switch. Installation would meet depth of working clearance and 25' tap rule. Concern is art. 230.70. Is this code legal?
230.70(A) means whatever your AHJ says it means and you have to ask him. I don't think what you say will fly but that is a 3000 mile away opinion.
Even if 230.70(A)(1) is not a problem, 230.72(A) may be. I would not consider a service disconnet on a different wall as being grouped with the other disconnect(s).
Your AHJ may have a problem with 110.3 (B). You are tapping or altering a piece of listed equipment. The manufacturer of the equipment may void it’s listing if it is altered in anyway.
Regards,
Elec N Spec
110.3(B) can bite you in the butt.
If you modify the bus in the field, the UL Listing is no longer valid; even if the manufacturer blesses your method.
If you decide to go ahead, you should plan on paying UL for a field inspection to certify that the board retains its UL Listing. Otherwise the AHJ can turn down the whole job.
I have enforced this. That is why I brought it up.
Elec N Spec
UL has specifically stated that unless the equipment is listed for a field tap using manufacturer supplied materials, then it would not be within the listing to tap the bus.
Last time I ran into a similar situation....a phone call to the Mfg. (CH), a field engineer arrived, looked, measured, sketched. 24 hours later I had Eng. signed/sealed drawings, and costs.
Came time to install, Factory Field guys came, fabricated a few extra bends, and made it work.
AHJ at site, looked, took copy of drawings & cert., left Approval sticker & cut-in card.
BTW, the overall $$$ was not that bad, considering what they did, plus the install.
John
PS: The same services are available from other mfg's, you just have to track down the right contacts.
Thanks for the input. I have a call into the inspector, should hear back in the morning, will let you know what he says.
Good luck. You gents are on the ball. I am seeing more and more non-listed equipment, fixtures and devices out in the field and some contractors have been hurt badly by basing their bids on equipment that they can’t use. Some time a real bargain can cost you more than what you were planning to save in the first place.
Regards,
Elec N Spec
bman, 230.2 allows for a second service when you exceed 2,000 amp.s Instead of trying to tap the 1,200 just add a 1,200 amp service.
The only restriction then is to label that it is service 2 of 2 and where # 1 is located. Also label #1 with information about #2
The rule is based on the size of the services NOT the calculated load.
"Do what's easy it may be right."
Alan--
Inspector said A-ok if tap is made on load side of main disconnect, Working depth maintained and 25' tap rule in effect.
If it is on the load side of the disconnect this is not an SE conductor. It is just a feeder.