SO Cord Drops to Machines??

[electrowatt]

Hello all. We have all seen and installed SO cord drops to machines in the middle of a warehouse or plant. Strain relief on both ends of course. Cords may have a box on the end or plug or some kind.

One of our customers has many of these and OSHA made a visit. Mentioned that cord drops of this sort are a NEC code violation. Can anyone elaborate on this and why? Much thanks

 

[iwire]

Very little info to go on but one common violation when electricians make when installing pendent drops is placing standard boxes at the end of them.

 

[mgookin]

Can you give some pictures?
Was it the drops themselves or something about them?

 

[iwire]

314.23(H) requires a strain relief to be 'threaded into a box with a hub'.

Does that mean you can add a say a Myers hub to a stamped steel 4" box?

Maybe, but not an argument I would get in with OSHA.

 

[electrowatt]

Alright here's a little more. A few of us have been researching this and I don't have the code sections however it appears that a cord drop of the SO family is not allowed anymore unless it's considered temporary. No pics..

Picture this. Open warehouse, Bar Joist ceiling with concrete floor, 35' from floor to bar joist, new 30a 208v 3 phase machine in the middle of the warehouse. Machine has a built in control panel and main breaker/disconnect for connection. For years as contractors we have dropped cord down to the machine. In this case it would be a 10/4 with a kellum grip at the top and a kellum/connector at the bottom into the control cabinet.

Some coworkers are saying these type of drops need to be rigid conduit now as cord is no longer allowed per the NEC unless the machine is not bolted down and can be considered temporary. As if the power drop was for testing operation of different machines being shipped out etc....

 

[Fulthrotl]

Alright here's a little more. A few of us have been researching this and I don't have the code sections however it appears that a cord drop of the SO family is not allowed anymore unless it's considered temporary. No pics..

Picture this. Open warehouse, Bar Joist ceiling with concrete floor, 35' from floor to bar joist, new 30a 208v 3 phase machine in the middle of the warehouse. Machine has a built in control panel and main breaker/disconnect for connection. For years as contractors we have dropped cord down to the machine. In this case it would be a 10/4 with a kellum grip at the top and a kellum/connector at the bottom into the control cabinet.

Some coworkers are saying these type of drops need to be rigid conduit now as cord is no longer allowed per the NEC unless the machine is not bolted down and can be considered temporary. As if the power drop was for testing operation of different machines being shipped out etc....

.
drop the cord down to a twist lock appropriately sized cord cap not touching the floor.
put a corresponding cord cap on a short length of 10/4 SO entering the cabinet.
use appropriate strain reliefs top and bottom.

 

[iwire]

Alright here's a little more. A few of us have been researching this and I don't have the code sections however it appears that a cord drop of the SO family is not allowed anymore unless it's considered temporary. No pics.

This is not true under the NEC or Federal OSHA.

From NEC article 400

400.7 Uses Permitted.
(A) Uses. Flexible cords and cables shall be used only for
the following:

(1) Pendants

It lists nine other uses as well.

Picture this. Open warehouse, Bar Joist ceiling with concrete floor, 35' from floor to bar joist, new 30a 208v 3 phase machine in the middle of the warehouse. Machine has a built in control panel and main breaker/disconnect for connection. For years as contractors we have dropped cord down to the machine. In this case it would be a 10/4 with a kellum grip at the top and a kellum/connector at the bottom into the control cabinet.

Ahh, not really a pendant in that case. I was picturing say a 125 volt 20 amp receptacle on the end of the drop.

In my opinion that is not a pendant so which one of the following reasong would you say allows the use of cord for this?

(2) Wiring of luminaires

(3) Connection of portable luminaires, portable and mobile
signs, or appliances

(4) Elevator cables

(5) Wiring of cranes and hoists

(6) Connection of utilization equipment to facilitate frequent
interchange

(7) Prevention of the transmission of noise or vibration

(8) Appliances where the fastening means and mechanical
connections are specifically designed to permit ready removal
for maintenance and repair, and the appliance is
intended or identified for flexible cord connection

(9) Connection of moving parts

(10) Where specifically permitted elsewhere in this Code

If none of those reasons fit your installation you will have to use a chapter 3 wiring method.

 

[zbang]

Alright here's a little more. A few of us have been researching this and I don't have the code sections however it appears that a cord drop of the SO family is not allowed anymore unless it's considered temporary.

Not necessarily correct, see 400.7 Uses Permitted (A)(6), (7) or (10). AFAIK these haven't changed in years. A lot of it depends on circumstances- it's hard to argue that a 5 ton machine that's been sitting in the same place for 5 years fits any of those. OTOH a 500 bound machine on casters probably would, even if it's been there for 20 years. (FWIW, cord drops are very common for places like commercial kitchens.)

Some coworkers are saying these type of drops need to be rigid conduit now as cord is no longer allowed per the NEC unless the machine is not bolted down and can be considered temporary. As if the power drop was for testing operation of different machines being shipped out etc....

Why rigid specifically? I doubt they can cite any code for that unless it's specific to the location/environment (which would have ruled out SO drops long before now). In most cases, properly-supported anything else would be fine. (And I hardly ever see large machine tools, like a Bridgeport mill, bolted down. YMMV on that.)

 

[electrowatt]

Thanks everyone. Got exactly what I was looking for. Great forum.

 

[tkb]

I wouldn't use type SO cord. We have always used bus drop cable.

 

[iwire]

A lot of it depends on circumstances- it's hard to argue that a 5 ton machine that's been sitting in the same place for 5 years fits any of those. OTOH a 500 bound machine on casters probably would, even if it's been there for 20 years.

I agree 100%

(FWIW, cord drops are very common for places like commercial kitchens.)

Yes and we do some very large supermarkets that likely have over a 100 cord drops between the sales floor and kitchens.

Why rigid specifically? I doubt they can cite any code for that unless it's specific to the location/environment (which would have ruled out SO drops long before now). In most cases, properly-supported anything else would be fine. (And I hardly ever see large machine tools, like a Bridgeport mill, bolted down. YMMV on that.)]

The advantage with RMC is there is an exception allowing less supports on RMC used for vertical drops.