Artcile 630.33 Disconnecting Means for Resistance Welders

[shroominator]

Is it the intent of this article that a circuit with multiple welding receptacles have a disconnect switch or circuit breaker at each receptacle? It seems to me that it does, if only to prevent having a live 480V receptacle waiting for someone to plug in equipment that has been forgotten to be turned off.

I have heard the argument that the on/off switch of the welder serves the purpose of the disconnect, and one is not needed in the supply circuit.

Would someone please clarify this for me?

Thanks,

Craig

 

[GoldDigger]

Is it the intent of this article that a circuit with multiple welding receptacles have a disconnect switch or circuit breaker at each receptacle? It seems to me that it does, if only to prevent having a live 480V receptacle waiting for someone to plug in equipment that has been forgotten to be turned off.

I have heard the argument that the on/off switch of the welder serves the purpose of the disconnect, and one is not needed in the supply circuit.

Would someone please clarify this for me?

Thanks,

Craig

I think that it would depend on whether there is only one welder that is being moved from location to location or there are multiple welders that may be used alternately or concurrently. I do not see any definitive answer on whether the welder switch can be considered the disconnect though. As long as all welders have such a switch and it also disconnects the control wires, it should serve that purpose. But so would unplugging the portable cord from the receptacle.
The code section appears to consider also hard-wired welders.

 

[don_resqcapt19]

If you have multiple welding receptacles on a single circuit and if you are using resistance welding equipment, then it appears that you willl need a means of disconnect at each welding receptacle. There are welding receptacles that are listed as disconnecting means.

If you have the more typical arc welding equipment, then 630.13 permits the switch on the welder itself to be the means of disconnect.

 

[shroominator]

If you have multiple welding receptacles on a single circuit and if you are using resistance welding equipment, then it appears that you willl need a means of disconnect at each welding receptacle. There are welding receptacles that are listed as disconnecting means.

If you have the more typical arc welding equipment, then 630.13 permits the switch on the welder itself to be the means of disconnect.

That is how I interpreted it. This is a power plant boiler structure, and these receptacles are for future maintenance. Not knowing exactly what type of welding equipment they will use for repairs a few years from now, I think the best approach is to have disconnecting means at each receptacle. I had specified receptacles with integral disconnects, but they are trying to save money by going with the receptacle only. I will keep checking back for more responses, but I am going to require disconnects at the receptacles at this time.

Thank you all for your input.

 

[GoldDigger]

duplicate, almost.

 

[GoldDigger]

I had specified receptacles with integral disconnects, but they are trying to save money by going with the receptacle only. I will keep checking back for more responses, but I am going to require disconnects at the receptacles at this time.

From don_'s post, it appears that instead of having a separate disconnecting means at the receptacle, there are receptacles where the receptacle itself is rated as a disconnecting means. This may be the best of both worlds for you, depending on their cost. (on the other hand, the first ones I looked at actually included separate integral disconnects interlocked with the receptacle so that it could not be removed or inserted under load. That seems to be something that you would want to enforce anyway.)

There are welding receptacles that are listed as disconnecting means.

 

[eHunter]

If my memory serves me correctly besides NEC, Fed/OSHA regs also come into play with permanent industrial maintenance welder outlets.
I believe disconnecting means, OCP and connection/enegizing/interlock are all required.
Deenergizing before connection/separation is a given for me.

 

[don_resqcapt19]

From don_'s post, it appears that instead of having a separate disconnecting means at the receptacle, there are receptacles where the receptacle itself is rated as a disconnecting means. This may be the best of both worlds for you, depending on their cost. ...

They are pricey...I was thinking of the Meltric Decontactor plugs and receptacles.