Volt-Amps for Unrated Welders

[tolind]

I'm trying to determine service for a new tenant finish. They currently have three welders on three 3 phase 40A circuits. The same will be repeated in the new building. My problem is that the building inspectors are going to be looking for panel information with the requirements of the welders. The existing equipment does not have the standard rating plates, and I don't have any way to determine the Volt-Amps it is actually drawing. The current ssytem is runnig on 230V, has a nema 14-50 configuration plug, and is connected to the panel by a 40A 3 phase circuit beaker. Does anyone have any suggestings.

 

[busbar]

You might discuss it with the Authority Having Jurisdiction (electrical inspector). NEC 630.34: Not much can be done without nameplates.

Seems the tenant should have the burden of providing acceptable documentation for his equipment. Likely the welders had nameplates at some point. BTW, 14-50 is not a 3ø device.

 

[advidana]

First of all the welders are single phase, I have not see any 3 phase welders ever.

Take it to a welding repair place and have then check it out and see if they can identify it.

 

[DougMSOE]

Maybe I am missing the point but what about measuring the voltage (open circuit) and the current (at the max current setting)?

 

[afterhrs]

Tolind,
I have seen three phase welders, the units I deal with are from Germany and do not have nameplates either. They were all installed before I was employed by my present company.
There has to be an engineer or electrician at your new
tenants company that has the technical manual that came with the welders when they were purchased. If you can have your tenant find these manuals, you will be able to comply with NEC 670.3 "Machine Nameplate Data." You or your tenent should be able to get a placard made to attach to the machine. The National Electrical Code(NEC) does not say that it has to be supplied by the equipment manufacturer, however, NFPA 79 "Electrical Standards for Industrial Machinery" may require that the equipment manufacturer supply the nameplate data.
If you get the nameplates made and have the documentation to back it up, a reasonable inspector may accept that, if you tell him the machine did not come with the permanent nameplate when it was purchased. At least the inspetcor should recognize that you are doing your best to comply with the NEC.


Best regards,
Afterhrs

 

[tolind]

Thanks for all the help. The welders in question are the German three phase variety. Thanks for pointing out that the 14-50's are not 3phase, but that is their existing set-up and it is working with their equipment. Unfortunetly I don't have access to measure the voltage or current in the building. I'm going to talk to the building inspector and get his thoughts. Thanks again for the help.

 

[jbartos]

Suggestion: The welders can be certified/labeled by a Nationally Recognized Testing Laboratory, if funds are available.
The welders tend to be used in industrial environment with electrical engineers and electricians on staff. This is where NEC is somewhat less stringent.