Flexible cable and equipment

[AntonLargiader]

Was in a wood shop the other day and there were at least two places where SOOW or SJOOW was coming out of a junction box, stapled to the rafters and posts, and ending in a twist-lock socket where a planer or whatever was plugged in. At first I thought it looked wrong, like a bad mix of temporary and permanent wiring, but then I saw that 368.56B seems to permit that sort of thing, if there is strain relief (which there was on one of them).

What I thought the biggest problem would be was that the cable on the posts was exposed to damage from ladders, forklifts, etc. Secondary to that was that it was stapled down and hard-wired to the J-boxes but maybe that's not a problem.

What's the legality of this sort of thing? Shop owner wants it to be safe. He does not plan to move any of the equipment and I think it's all 30A. One of the cables is 12 AWG and one is 10 AWG. In my place it's all conduit to receptacle boxes but I know woodworkers just love their cords and twist-locks. There must be a reason.

 

[matt_i]

I'm no code quoter but I can say the #12 carrying 30A is no-bueno.

 

[AntonLargiader]

It might have been the equipment cord that was 12; I'll have to check. And I'd want to verify the breakers and motor ratings before I worried about that. My curiosity (and his) is more about the use of the semi-attached S-cord.

EDIT: and there's other questionable stuff we saw. In one place a conduit comes down out of the box, turns to lie along the floor, and then ends with some SOOW coming out and continuing on the floor. This is all concealed behind the machinery that uses it (a panel saw being fed by an RPC).

 

[sberry]

Stapling up cord is a no no.

 

[alfredeneuman]

, but then I saw that 368.56B seems to permit that sort of thing, if there is strain relief (which there was on one of them).

Article 368 applies busways only.
368.2 gives the definition for busways. A junction box isn't a busway.

 

[theoldwizard1]

Stapling up cord is a no no.

TRUE ! A staple is not a "strain relief".

Not sure about termination. The make pendant boxes ($$$$ !!!) but I have also seen single twist lock receptacle with strain reliefs.

This is actually a GOOD option for a shop that has equipment that is moved around a lot.

 

[AntonLargiader]

The staples are not there for strain relief. Let me describe it a bit better.

S-cord from J-box in rafters, stapled loosely along rafter, down post to a regular "chinese finger puzzle" style strain relief, then a few more staples just to keep it from flopping around to about 2" above the floor, where there is a twist-lock socket. The saw/planer/whatever is plugged in there and there is a staple holding its cord to the post as well.

Times about three, plus some other similar stuff that runs along the floor.

The shop owner is happy to make it right. This is how it was at the previous location and how the "house electrician" installed it here. He probably does not want a fire or other dangerous situation any more than anyone else does.

So, based on the above comments is it safe to say there is no variation on the existing setup that is legal? Or is it close to some acceptable wiring method? Is there something he can do to make it safe other than installing conduit to a receptacle box, and changing plugs?

I'll take a better look at the motors he has. The band saw has a 1 HP (7A @ 240V) motor but he wants to bump it up to maybe 1.5 or 2. It's on a 30A breaker now.

 

[sberry]

I will let some others comment on motors, multiple motors on the same circuit. But if it has its own thermal and a 14 cord may be legal on a 30. It's been so long since I read thru all that can't remember all the rules.
Cord stapled up isn't legal. Cable may be under some circumstances. Cord to an outlet may be. How unsafe this may be speculative. There is good reason for the code. Some pendants with strain relief might not bother me if it kept stuff off the floor.

 

[AntonLargiader]

Some table showed 12 on a 30 being OK for a 3HP motor but I'm not sure if that applied to cord. There seemed to be some restrictions on cord.

How are most wood shops wired with respect to this? I have experience with two, and neither is probably a very good example.

 

[alfredeneuman]

Since you have a Code book, see Table 400.5(A)(1) for the ampacity of cord.

To sort out this mess, you'd have to run conduit with boxes directly above each machine's cord.
Use a cord connector (not a 2 screw Romex connector) to attach to the box.
(It's better to use "drawn" boxes, but if welded avoid the welded sides. The have a habit of the welded sides failing)
Drop the cord to a convenient height {EDIT: above the floor} and use a connector body (the female version of a plug), not a box. Special boxes designed for the purpose are $$$$.

You shouldn't have to use a ladder to access the plug.
If the plug isn't rated for the HP of the machine, a disconnect would be needed.