Using SOOJ cable. 6

[itsmoked]

I frequently have customers (cheapskates) that want to use SOxx in lue of conduit. I seem to recall you can't just run SO all over the place instead of a clean fixed installation, I'd end up looking like those trade-show power distribution boxes. Do you recall what is allowed?

I'm about to go over this with yet another customer and since the machine has an SO cord depending from it already I can easily hear him arguing "that's what the machine already has".

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

Hi Keith:
Here is an excerpt from the Canadian Code that may help you searching the NEC:

4-012 Uses of flexible cord (see Appendix B)
...........
(3) Flexible cord and cord sets shall not be used
(a) as a substitute for the fixed wiring of structures and shall not be
(i) permanently secured to any structural member;
(ii) run through holes in walls, ceilings, or floors; or
(iii) run through doorways, windows, or similar openings;
(b) at temperatures above the temperature rating of the cord or at

There are exceptions that allow it to be used on equipment, and equipment wiring falls under different rules from building wiring.
Start by searching the NEC for SO**

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[RedSnake]

It is the same in EU you can only use what we call RDEO flexible rubber cords for none permanent connections.
Like waross describes above.

NEC 400.7 Flexible Cords and Cables. Uses Permitted

https://www.electricallicenserenewa...ation-Courses/NEC-Content.php?sectionID=111.0

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Palletjack]

Are you looking for specific NEC articles? 400 would be the place to start.
Here’s a pretty good summary from EC&M

https://www.ecmweb.com/national-ele...888058/flexible-cords-cables-and-fixture-wire

SO cable use plainly says “pendant or portable”

Also.. SOOJ?
Or SJOO.
The j is for junior
It’s 300V cable

 

[TugboatEng]

TC-ER is meant to be run outside of conduit. TC-ER doesn't have good flexibility or abrasion resistance. For that, I believe TF is superior. It's sometimes called studio lighting cable. TF has poor oil resistance. Marine shipboard cable is all designed for exposed run as well. Shipboard cable is broadly applicable but again has poor flexibility that gets worse as it ages.

 

[itsmoked]

Thanks everyone for the guidance. I think I have it now. Thanks Pallet for the J reminder.

I see the zillion machines I've seen with cords even though you couldn't move half them with a forklift are using the "vibration isolation" angle.

The can't "permanently affix to the building" will make my particular case a very interesting argument.

TC-ER.. this is for a laser. "Lighting Cable".


Keith Cress
kcress -

http://www.flaminsystems.com

 

[jraef]

The NEC basically says the same thing that the CEC quote from Bill says, but adds a few more conditional uses. Article 400.7(A)




" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[FacEngrPE]

You can run type TC (or another type allowed in tray) along with either ladder tray or wire mesh tray. Note that Type SO is not approved for this use. For the last couple of feet you can do something like this to make this short cord not permanently connected to the building, and possibly provide an OSHA compliant disconnecting means.

 

[TugboatEng]

How often is that motor getting disconnected to justify adding a $1000 plug to it?!

 

[RedSnake]

Every time anyone is going to work on the motor or the conveyer. ;-)
In EU you need to have a visibel open connection or a lockable disconnect breaker by the motor.

/A


“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[waross]

That leads to the question, how much a minute is loss of production downtime calculated at.
With a permanent connection, the plant safety protocol may require both a millwright and an electrician to change a motor.
With a plug connected motor, an electrician is not required. If the conveyor is in a warehouse, they may not have an electrician on staff. $1000 to reduce the payroll by one tradesman? Any MBA will go for that.


--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[RedSnake]

And then I need to ask what makes that disconnect contact so expensive?

/A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[TugboatEng]

Those plugs have an internal contactor that breaks the connection as the plug removed. They save the need for a separate disconnect switch.

 

[waross]

Those plugs have an internal contactor that breaks the connection as the plug removed.

That is a requirement for the explosion proof receptacles.
In non-hazardous locations a normal pin type connector may be used.
That drops the price a lot.


--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[TugboatEng]

Surprisingly, the switch rated plugs cost about the same as the legacy type aluminum bodied pin and sleeve units.

https://meltric.com/all/switch-rated.html

 

[jraef]

That is a requirement for the explosion proof receptacles.
In non-hazardous locations a normal pin type connector may be used.
That drops the price a lot.

Even if you have a standard pin and sleeve connector, they cannot be disconnected under load so one would need a local disconnect too. The Meltric (and their subsequent clones) forego the need for the extra disconnect because they are listed as "load break" disconnect devices.

I have used the Meltric system extensively on portable machinery for mining and rock crushing, where the need to move machines and conveyors quickly as the work area changes is of primary importance.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[LionelHutz]

No they don't. Just press the stop button before disconnecting it. UL508A allows it and just requires the connector to be labelled "For disconnecting use only, not for current rupturing" when the connector is not horsepower rated.

Of course, it is safer to provide horsepower rated plugs, but it certainly is not necessary. Lots of mines I deal with don't use horsepower rated plugs.

 

[waross]

How would having a control transformer in the above situation affect the current rupturing status?

No affect on the motor leads or motor current. The control transformer will be upstream at the motor starter.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[TugboatEng]

I was thinking about disconnecting the controller as the disconnect switch is usually in the controller panel and also disconnects the control transformer. I realized later that you were talking after the starter.

 

[RedSnake]

You mean the main breaker?
It least for ordinary low volt applications they are load breakers at least here, mening I can turn it of with full load power on, if needed.
Normally you stopp the machine first, just to save on the breaker and you might have less problems starting it up again.

For plugs ours are rated for 16, 32 or 64 amps.
And you have to have one that can handle the motor load to begin with.
I would not hesitate to pull a plug with load on, if I needed to in an emergency situation.
They are made so that the arc will go out before you have pulled it full out.
Of course you might need to exchange it afterwards though.
But normal procedure is to turn the load power off first.

/A



“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein