flexible cords

[safetygal]

I'm new to this forum and am hoping you can help me with an issue. I have tried interpreting the NEC and OSHA on this issue, but electrical practices are not my strength. I have come to a conclusion, but am not sure it is correct.

Situation: There are welding machines are hooked up to main disconnects using flexible cords. The majority of cords are hard wired into machine and disconnect. A couple machines have a flexible cord with a plug and are connected to another flexible cord that has receptacle (quick connect) on one end and hard wired into disconnect at other end (pig tail?). This is inside a manufacturing facility, not at a construction site.

Question: Are these uses of flexible cords compliant with the NEC and OSHA? :?

Thank you so much.

 

[petersonra]

I don't know if it is an OSHA issue or not. If they are not plugged into an outlet they are likely not NEC compliant.

in any case, it is doubtful they are any kind of serious safety hazard. just not code compliant.

 

[pfalcon]

A topic highly despised in industrial facilities.

See (NEC) NFPA70:400.7 Uses Permitted. See (NEC) NFPA70:400.8 Uses Not Permitted.

Many industrials sites do not permit the use you appear to have described but it's not clear cut. My facility does not at this time permit such an install.

Pros:
400.7(6) permits if there will be frequent swapping of machines. I don't see frequent moving of welders. So this clause doesn't permit the install.

400.7(10) makes it muddy by permitting its use but only if it's specifically permitted elsewhere. This requires something in the code to actually grant permission; not a blanket allowance. So this clause probably doesn't permit the install.

Cons:
400.8(1) is sometimes mis-applied - the drop to the machine isn't really "fixed wiring of a structure". So this clause doesn't block the install.

400.8(4) talks about attaching to building structures and reference article 368.56(B) which requires the machine qualify under 400.7(3),(6),or (8) generally. Which a welder probably doesn't. A lot of these runs can't avoid attaching to building structures as they are flexible . So this clause may block the install.

400.8(7) requires it not to be subject to physical damage. A lot of industrial facilities believe these drops can't be protected. Requires a judgement by the facility. This clause may block the install.

 

[pfalcon]

I don't know if it is an OSHA issue or not. If they are not plugged into an outlet they are likely not NEC compliant.

in any case, it is doubtful they are any kind of serious safety hazard. just not code compliant.

A welder would have to qualify under 400.7(A)(6) "Connection of utilization equipment to facilitate frequent interchange." to meet 400.7(B) and be code compliant. I doubt they plan to move the welder several times a year.

 

[jim dungar]

A welder would have to qualify under 400.7(A)(6) "Connection of utilization equipment to facilitate frequent interchange." to meet 400.7(B) and be code compliant. I doubt they plan to move the welder several times a year.

IMHO, we could use 400.7(A)(6) for just about every piece of equipment in an industrial setting.
The NEC does not define the time frame for 'frequent'. What if a welder gets moved once per year for the next 50 years? How about a welder that gets moved 4 times in one week and then sits in one place for the next 3 years, when it again gets moved 4 time in one week?

 

[augie47]

IMO, You could probably use 400.7(A)(6) to justify the cord, but note that 400.7(B) does require such an install to use an attachment plug.

 

[pfalcon]

IMHO, we could use 400.7(A)(6) for just about every piece of equipment in an industrial setting.
The NEC does not define the time frame for 'frequent'. What if a welder gets moved once per year for the next 50 years? How about a welder that gets moved 4 times in one week and then sits in one place for the next 3 years, when it again gets moved 4 time in one week?

IMO, You could probably use 400.7(A)(6) to justify the cord, but note that 400.7(B) does require such an install to use an attachment plug.

Gotta love subjective terms but Jim and Augie are correct. If someone can sell that the welder is being moved "frequently" then as Augie stated.

 

[petersonra]

a lot of small machines get moved around for cleaning and maint but always get put back where they started.