Using Welding Receptacles

[CPS Elec.]

I have a welding rec with a 100A 3 phase 480V breaker, would it be acceptable to utilize this for portable heaters?
One example would be a 30KW with aproximately 50ft of 6/4 SOW, there is a 100A rated disconnect mounted on the heater with 40A or 45A fuses?

 

[don_resqcapt19]

You need to provide overcurrent protection of the cord at the welding receptacle. 240.5

 

[jap]

Without looking it up my answer would be no you can't.

What would protect the cord between the welding outlet and the Heater?
You couldnt apply any type of Tap rule either.

How do they have a 100 Amp Rated disconnect with 40 and 45 Amp Fuses? Fuse Reducers?

 

[augie47]

I have a welding rec with a 100A 3 phase 480V breaker, would it be acceptable to utilize this for portable heaters?
One example would be a 30KW with aproximately 50ft of 6/4 SOW, there is a 100A rated disconnect mounted on the heater with 40A or 45A fuses?

Right off hand I see a couple of problems. First, you would need to comfirm the wire size. Welders allow an "undersized" conductor on occasion that allowance is carried over to a receptacle installation.
Secondly, 6/4 does not have the ampacity for the 100 amp protection. (f it happens to be a factory cord, rules change )

 

[CPS Elec.]

Is this because the cord end is field installed? Im just thinking about other similar comparisons on a smaller scale, like plugging something that draws only 5A and is plugged into a 20A rec. It is likely that this equipment would have 16 awg or smaller wire and not rated for 20A?

 

[CPS Elec.]

The wire from the breaker to the welding rec. is #2 and approx. 300ft.

 

[CPS Elec.]

You mentioned that rules might change if its a factory cord, what about a factory recomended cord? Im being told these heaters did not come with cords, but I would think the manufacturer would give a minimum recomendation?

 

[jap]

If it were me, I'd probably put a junction on the line side of the Welding Recptacle and extend the 100a #2 wiring over to a 60a Fused Disconnect to feed the portable heater.

 

[david]

I have a welding rec with a 100A 3 phase 480V breaker, would it be acceptable to utilize this for portable heaters?
One example would be a 30KW with aproximately 50ft of 6/4 SOW, there is a 100A rated disconnect mounted on the heater with 40A or 45A fuses?

Is this a multi-outlet welding circuit in a plant? Is this circuit still being used for a welder (welders)?
Since you said portable heaters how many are you adding on this circuit?
What all is this circuit going to be used for?

 

[guschash]

If they'd are portable heater, you not planning on using them as permanent . I wound make the cord with a disconnect. Welding plug-disconnect - receptacle on disconnect - cord to heater.

 

[renosteinke]

Just a fine point ... What's the wire size?

The effect of the NEC for welding circuits is that you can often use a really huge breaker with tiny wire. It all comes down to the nameplate info of the welder.

Just because you have a 100-A breaker, don't assume you have 100-A wire.

 

[guschash]

We always used welding cable to disconnect .

 

[CPS Elec.]

Its just a single welding rec. on each circuit, and plugging in one heater.

 

[don_resqcapt19]

Its just a single welding rec. on each circuit, and plugging in one heater.

So what code section will permit you to run 50' of 6-4 cord with an 100 amp OCPD?

 

[CPS Elec.]

If it were me, I'd probably put a junction on the line side of the Welding Recptacle and extend the 100a #2 wiring over to a 60a Fused Disconnect to feed the portable heater.

I think I'm going to go this route. There are several of these welding rec. all through the plant, and opperations frequently uses them for portable heaters. Thanks

 

[kwired]

Make up a short 100 amp cord,provide your necessary reduced overcurrent protection somehow on the load end of that cord and then supply the smaller cord with proper protection.

 

[jap]

Make up a short 100 amp cord,provide your necessary reduced overcurrent protection somehow on the load end of that cord and then supply the smaller cord with proper protection.

The 100 Amp 480v Male cord cap,short piece of 100a rated cord and reduced overcurrent protection makes this scenario get very pricy very quick.

 

[weressl]

You need to provide overcurrent protection of the cord at the welding receptacle. 240.5

In practical terms it is almost never done.

 

[kwired]

The 100 Amp 480v Male cord cap,short piece of 100a rated cord and reduced overcurrent protection makes this scenario get very pricy very quick.

True.

How about tap the 100 amp circuit install proper disconnect (all with "hard" wiring methods)then a receptacle and cord sized for the need? Some price there also but probably not quite as bad as the other option.

Some will argue you can't tap a branch circuit only a feeder, If you are in that crowd then you will need a disconnect and overcurrent protection for the 100 amp receptacle also - more price.