Welder Supply

[elecsup1]

Is it permissable to supply an arc welder tagged 230 v 113 amp 100% duty cycle on the primary side, operated manually at varying intervals, with a circuit wired and fused at 50 amps?
Also, for an arc welder wired and fused at 100 amps supplied by an overhead bus, can a cord connected to the switch on the bus plug and hanging down to a height of 4-5' serve as the disconnecting means if it is labeled as such? The welder has an on/off switch and is hard wired to the overhead bus plug.
I am in central Maine.

 

[elecsup1]

Re: Welder Supply

Any comments or suggestions are greatly appreciated.

 

[shocker3218]

Re: Welder Supply

I can't recall the code section right now (no book in front of me), but on a recent job we wired 50 amp rated plugs on 100 amp breakers. There is an exception in the code for welders that allows this.

Check out article 630 (1999)

[ July 12, 2004, 11:15 PM: Message edited by: shocker3218 ]

 

[steve66]

Re: Welder Supply

Article 630 addresses welders. 630.11(A) says the ampacity of the supply conductors can't be less than Ieff listed on the welder. If Ieff is not listed, then the supply conductors shall be rated for the primary current rating times the duty cycle (with 100%=1).

Since your welder is rated at 100%, I think you need a supply rated for the full 113 amps.

Steve

 

[elecsup1]

Re: Welder Supply

Thank you for your input shocker3218 and steve66. To be on the safe side I am going to supply it with the full rated current and install a disconnect switch.