N 400.7, Drill Press

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Mike Furlan

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Lemont Il
It is very common to see permanently mounted industrial equipment, drill presses for one, that are powered by flexible cords. This seems to be in violation of NEC 400.7, as such devices are not permitted.

Specific examples of such equipment:

Steel City Industrial Band Saw model number 50200, 50250, 50300.
Steel City Industrial Bench Grinder model number 15400, 15410.
Steel City Drill Press model number 20520.

All these items have the CSA logo (C and US) on the front page of their manuals, and detail permanent mounting and wiring with flexible cords.

Can you think of any way that these devices could be in compliance with the NEC when installed with flexible cords?
 
What if the equipment is deriving power from a bus duct. Would you have to hard wire that. I don't think so.
Plug and cord is very common and acceptable in most industrial applications. I think that is why someone invented the twist lock recepts and plugs.
 
Mike Furlan said:
All these items have the CSA logo (C and US) on the front page of their manuals, and detail permanent mounting and wiring with flexible cords.

Can you think of any way that these devices could be in compliance with the NEC when installed with flexible cords?
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Just my opinion, but I would say the instuctions in the manual and 400.7(7) would permit flexible cords with attachment plugs. Since this is industrial equipment (8) would not apply.

I would also have a question about this as the machines would probably sit there for years.
 
John Valdes said:
What if the equipment is deriving power from a bus duct. Would you have to hard wire that. I don't think so.
Plug and cord is very common and acceptable in most industrial applications. I think that is why someone invented the twist lock recepts and plugs.
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Yes I know that it is very common, and seems to be acceptable. I'm just trying to find where in the code that it is justified.
 
buck33k said:
Just my opinion, but I would say the instuctions in the manual and 400.7(7) would permit flexible cords with attachment plugs. Since this is industrial equipment (8) would not apply.

I would also have a question about this as the machines would probably sit there for years.
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Well, but there really isn't that much noise or vibration from a drill press. Hard to sell somebody on this point.

And I think, having just found out about it, that NFPA 79, rather than NFPA 70 applies.

From NFPA 79, 14.4.5.1:

"Where equipment is removable, connections to it through a polarized attachment plug and receptacle (plug/socket) combination shall be permitted."

Now I just have to find out the exact meaning of "removable" in this context.

There are no definitions in this book.
 
Did a quick check on Steel City tools. Just a quick check but the types of tools on their product pages appear to be "removeable". Of course my wife would disagree.

We would hard plumb the outlets down to the tools. The plug and cord would be acceptable.

I would mention however that with our aggressive safety department that I doubt most of them would pass the safety inspection for guarding et al.
 
pfalcon said:
Did a quick check on Steel City tools. Just a quick check but the types of tools on their product pages appear to be "removeable". Of course my wife would disagree.

We would hard plumb the outlets down to the tools. The plug and cord would be acceptable.

I would mention however that with our aggressive safety department that I doubt most of them would pass the safety inspection for guarding et al.
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The all appear to be removable to me too.

But I'm hoping for a clear, unambiguous definition of "removable."

All of the Steel City tools I mentions are made to be bolted down, to the bench or floor. But we agree that they are "removable."

What then do you say about a heated press, also powered by cord and plug, that weighs about half a ton, but is not bolted to the floor and is left sitting on blocks so that it can be easily moved with a pallet jack?

It will take me longer to remove a drill press bolted to the floor than the much bigger heated press.
 
At a machine shop where we do service work, we've converted, over the years, all of their equipment to cord and plug using correctly sized NEMA receptacles, plugs, and SO (or SOJ?). The largest machine is an 80 amp CNC beast that took a very expensive plug and recept! But we did it specifically because they move all of their machines around 4 or 5 times a year, re-tooling the shop areas for new projects. They have about four places now that they can plug in that 80a thing, and they love not having to call us out as much. We've got enough work so we don't mind them being happy about that either. Most of the plugs are the 30 and 50a variety (think welders). There are a few drill presses in the mix, steel lathes, presses, etc.

They do bolt things down, but they use the drop-in anchors (female threads below the slab surface) so when they abandon a spot there's just four small holes in the floor.

Does the absence or presence of floor bolts make a machine movable or unmovable? Not in my experience. [/opinion] The AHJ hasn't ever failed an inspection for us there. (but I realize that doesn't mean we've not broken some code somewhere...)

Jeremy
Tulsa, Ok
 
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jerm said:
Does the absence or presence of floor bolts make a machine movable or unmovable? Not in my experience. [/opinion] The
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I agree.

Neither does the size of the equipment, I worked in a plant where the in house maintenance guys would move machines weighing several tons around like we move our tool bags.
 
jerm said:
Does the absence or presence of floor bolts make a machine movable or unmovable? Not in my experience. [/opinion] The AHJ hasn't ever failed an inspection for us there. (but I realize that doesn't mean we've not broken some code somewhere...)

Jeremy
Tulsa, Ok
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Yes, I still need to find the citation in the code that says it is OK.
 
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