ECN Forum Forums Code Related Discussion NEC & other Code issues Disconnecting means for portable welding machines

Looking at 630.13 it says A disconnecting means shall be provided in the supply circuit for each arc welder that is not equipped with a disconnect mounted as an integral part of the welder. The disconnecting means identity shall be marked in accordance with 110.22(A).
The disconnecting means shall be a switch or circuit breaker, and its rating shall be not less than that necessary to accommodate overcurrent protection as specified under 630.12.

No mention is made of cord and plug unless you consider the phrase a disconnect mounted as an integral part of the welder to include a plug and cord, which I believe it does.

It does say The disconnecting means shall be a switch or circuit breaker but I believe this is referring to the required disconnect if one does not exist on the welder, not a requirement that the integral disconnect on the welder be a switch or a circuit breaker. If this is taken to mean that the integral disconnect on the machine must be a switch or a circuit breaker that would mean the NEC is telling the manufacturer how to build the machine, which isn't in the scope of the NEC. A portable welder manufactured with a cord and plug already has the integral disconnect mentioned, making the rest of the wording of 630.13 not applicable to that machine. IMHO Thoughts?

I suppose this is where the NRTL steps in. I have never seen a portable welder that didn't have a disconnect switch. Maybe if someone has access to U/L standard 60974-1 they could verify this but they want $500 for it.

Most cord and plug welding machines only have a switch that switches one of the lines.But you bring up another point, 630.13 says a disconnecting means but it does not say a service disconnect that opens all ungrounded conductors.

Seems to me that "portable" means either a cord & plug connected unit or a welder with its own generator.
While your larger plugs -- like the ones used on dryers and ranges -- are typically not evaluated as disconnecting devices (meaning under full fault current), I have no issue considering the plug on a welder as a disconnect. This is because I expect a welder to draw a full load only rarely and for very brief periods.
If experience is a guide, consider yourself lucky a plug is used at all. Welding operators routinely connect bare leads directly to line mains without benefit of any overload connection. If they don't double-lug to an existing connector they use alligator clips or (gasp!) modified clamps.