50AMP 40AMP 30AMP plugs

[kwb210]

50AMP 40AMP 30AMP plugs
I plan on having a couple of plugs available for welders and whatever higher voltage tools may get used in my shop. My plan is to have an area right next to the service panel with these various plugs hard wired a few feet away. I'll label the plate surrounding each plug with the pertinent info, although I realize the plug design "should" prevent the wrong plug being used. My question is what types of plugs and what gauge of wires should I wire in and what AMP's for the breaker would be normal. I would like to be prepared for pretty much any kind of welder. I will have the opportunity of using my electrical guy to wire these in while he is finishing adding circuits for my lighting etc.
kurt

 

[Ign]

I run nothing but the 6-50R. I wire it on 50A breakers w #6. If something comes with a plug other than the 6-50P, I just replace the plug.

 

[bluesman2a]

I run nothing but the 6-50R. I wire it on 50A breakers w #6. If something comes with a plug other than the 6-50P, I just replace the plug.

I'll agree with this whole-heartedly. With the exception of my lift and compressor (both 30A load/breakers with #10), I wired the WHOLE shop with #6 on 50A ckts. Regardless of the rating of the breaker/wire, I still put 6-50R plugs on all the 240V outlets. This way I can have just ONE plug type and ONE set of extension cords.

A side note here: the best deal I found on #6 was at Home Depot. They carry a pre-packaged 125' spool of the stuff for around $130. Due to the number of welding/plasma locations I wanted I think I have about 3 of these into my shop total. On the same note, HD also carries the Pass & Seymore outlets/plugs which I like better than others I've seen.

 

[Notch1988]

My welder only needed a 30 amp circuit so I sort of planned for that. I have three 30 amp circuits but I used #8 so I can up it to 40 amp in the future if need be. And I agree with the 6-50R plugs, that's all I used on everything.

PS - does anyone know if they make 8/3 SOOW? Can't find anthing bigger than 10/3 at HomeDepot.

 

[bluesman2a]

PS - does anyone know if they make 8/3 SOOW? Can't find anthing bigger than 10/3 at HomeDepot.

Yes, they do. I think I got my last at Lowes. Before you buy the bulk stuff, check out their Yellow-Jacket pre-made, I THINK it's 8/3, and as I remember it was cheaper to buy the premade cord than it was to JUST buy the same amount of wire, and they were VERY nice cords.

 

[trovato]

I run nothing but the 6-50R. I wire it on 50A breakers w #6. If something comes with a plug other than the 6-50P, I just replace the plug.

Just so you know... when a device has a 30 Amp plug on it, it is depending on a 30 Amp breaker being there to protect it. What you are doing is bypassing this safety and hoping that in a worst case scenario it can handle 50 Amps before the breaker trips without burning the house down. The whole thing was counterintuitive to me as well. You would think that providing a bigger breaker with corresponding heavier wire would be no problem. And in fact, it will probably be fine, but it is not correct. I was recently educated on the finer points of this by an electrician friend. Just thought I'd pass it along.

 

[bluesman2a]

Just so you know... when a device has a 30 Amp plug on it, it is depending on a 30 Amp breaker being there to protect it. What you are doing is bypassing this safety and hoping that in a worst case scenario it can handle 50 Amps before the breaker trips without burning the house down. The whole thing was counterintuitive to me as well. You would think that providing a bigger breaker with corresponding heavier wire would be no problem. And in fact, it will probably be fine, but it is not correct. I was recently educated on the finer points of this by an electrician friend. Just thought I'd pass it along.

In this scenario, the issue is NOT the plug OR the wire, either of these can be over-size and not cause a problem with the end device. The issue is the BREAKER. If you know you're going to have a 30 amp load on something for an extended period of time, you can easily swap in a 30A breaker.

 

[trovato]

In this scenario, the issue is NOT the plug OR the wire, either of these can be over-size and not cause a problem with the end device. The issue is the BREAKER. If you know you're going to have a 30 amp load on something for an extended period of time, you can easily swap in a 30A breaker.

Right. Oversize wire is no problem. Using a 50 Amp plug and swapping the breaker every time you switch to a 30 Amp load is just as safe, but not to code. This is because they don't trust that you'll change the breaker every time to match the load. Look, I'm not the code police. Do what you want. I just think you should know the rules and then make informed decisions.

 

[bluesman2a]

Look, I'm not the code police. Do what you want. I just think you should know the rules and then make informed decisions.

Agreed, didn't mean to imply otherwise.

 

[kwb210]

Great comments, thanks. Is it overkill to wire in more than one plug? A 30, 40 & a 50 each on their own breaker? I'm trying to get in all my wiring before I drywall. That feeling as the last piece goes up that I forgot to run one more length of wire to a location...
kurt

 

[PAToyota]

I put in another vote for not over-sizing breakers. The manufacturer has installed that plug there for a reason - so that the equipment is properly protected by the appropriate sized circuit breaker.

As mentioned, over-sizing the wire is not a problem. I actually over-sized all wiring in my shop. Remember that the wire sizing that the NEC gives you is the minimum acceptable - also, running larger wire helps with voltage drops.

 

[PAToyota]

Is it overkill to wire in more than one plug? A 30, 40 & a 50 each on their own breaker?

In my book, versatility is never overkill...

I have dedicated outlets for my compressor and TIG welder because they aren't going to be moving around. But then I have outlets for the MIG and plasma scattered around the shop because I will be using them in different areas. You could always make up 220V heavy-duty extension cords, but I prefer to have accessible outlets so that I can limit trip hazards while working.

 

[kwb210]

In my book, versatility is never overkill...

I have dedicated outlets for my compressor and TIG welder because they aren't going to be moving around. But then I have outlets for the MIG and plasma scattered around the shop because I will be using them in different areas. You could always make up 220V heavy-duty extension cords, but I prefer to have accessible outlets so that I can limit trip hazards while working.

That's my feeling. I have more 110v outlets than usual, what's usual(?), but I prefer an accessible outlet over extension cords, I have a problem towards tripping hazards if one is nearby...
Thanks, I'll pre-wire in a couple of plugs. They will be just a few feet from the service panel so I can probably purchase a few short pieces of left over wire at the hardware store. I'm guessing that for $25 I can get a couple of plugs, breakers and wire.
kurt

 

[cj7jeep81]

That's my feeling. I have more 110v outlets than usual, what's usual(?), but I prefer an accessible outlet over extension cords, I have a problem towards tripping hazards if one is nearby...
Thanks, I'll pre-wire in a couple of plugs. They will be just a few feet from the service panel so I can probably purchase a few short pieces of left over wire at the hardware store. I'm guessing that for $25 I can get a couple of plugs, breakers and wire.
kurt

i'd raise your budget up a bit. you'll want to get good quality plugs/receptacles, and those alone will run more than $25. if you're wanting to do 3 outlets, i'd be expecting closer to $100 for all the stuff (if not more).

 

[kwb210]

i'd raise your budget up a bit. you'll want to get good quality plugs/receptacles, and those alone will run more than $25. if you're wanting to do 3 outlets, i'd be expecting closer to $100 for all the stuff (if not more).

Well, that's why I have written down my estimates/budget in pencil rather than pen. It just goes up. I agree on purchasing higher quality plugs/receptacles, done right its done once.

 

[goodfellow]

Match the breaker with the equipment. When/if you get new equipment, it's not a big deal to switch to a higher/lower breaker. I have several 50 amp runs for the plasma, MIG and small stick welder. My compressor is on a dedicated 30 amp run, while the 300 amp TIG is on a dedicated 100 amp circuit. All the runs were wired with 0 AWG (got a good deal locally) so I only have to switch breakers when my equipment inventory changes.

 

[MustangRick]

If you are planning on putting them close to the panel then I would definitely do it.

If you are looking at a good distance away from the panel, then look into conduit so that you can pull it in later. If it is a straight wall, I would think you could put 1" or so conduit in and pull what ever you need later. At the end of the conduit, put in a few quad boxes so that you can have a few different circuits in there. Make sure you spec out what size conduit you need since you are looking at some fairly large wire.

 

[turboimpala]

Just so you know... when a device has a 30 Amp plug on it, it is depending on a 30 Amp breaker being there to protect it. What you are doing is bypassing this safety and hoping that in a worst case scenario it can handle 50 Amps before the breaker trips without burning the house down. The whole thing was counterintuitive to me as well. You would think that providing a bigger breaker with corresponding heavier wire would be no problem. And in fact, it will probably be fine, but it is not correct. I was recently educated on the finer points of this by an electrician friend. Just thought I'd pass it along.

There is nothing wrong with connecting a device that uses 30 amps into a receptacle, wire and breaker all rated for 50 amps.
The danger is when the trip current of the breaker exceeds the current capacity of the receptacle and/or wire.
Then, if you connect a device that pulls more current than what the receptacle or wire is rated at, but does not exceed the trip current of the breaker, you can overheat the wire and start a fire.
To be safe, make sure the receptacle current capacity doesn't exceed the wire current capacity, and that the breaker trip current doesn't exceed the capacity of the wire or the receptacle.

 

[cj7jeep81]

are there limits to what wire guage you can run on a breaker? i would think it would be difficult/impossible to run the heavier guauge wires on the smaller breakers (due to the size of the connection). is there a pratical limit? i'd really like to be able to do this when i build my shop to allow for growth, but this is my only concern.

 

[Lyaec350]

There is nothing wrong with connecting a device that uses 30 amps into a receptacle, wire and breaker all rated for 50 amps.
The danger is when the trip current of the breaker exceeds the current capacity of the receptacle and/or wire.
Then, if you connect a device that pulls more current than what the receptacle or wire is rated at, but does not exceed the trip current of the breaker, you can overheat the wire and start a fire.
To be safe, make sure the receptacle current capacity doesn't exceed the wire current capacity, and that the breaker trip current doesn't exceed the capacity of the wire or the receptacle.

Agreed. Think about it in your house, you don't put your little clock radio that pulls 0.5A on a special 1 amp breaker, you plug it in to the standard 15A outlet on the wall with no problems.

The problems start to happen when you put a 50A breaker on a circuit w/ a 30A recept, wire, and plug a 50A load in to it... I mean granted, you don't want to grossly oversize your breakers, but using a 40A welder on a 50A circuit is not going to be a big deal. Breakers don't magically trip at their stated amperage anyway, its a function of amperage and time, usually requiring 2x the rated amperage for a couple seconds before tripping.

***I don't know code by heart, but this seems to be common sense.

 

[trovato]

Agreed. Think about it in your house, you don't put your little clock radio that pulls 0.5A on a special 1 amp breaker, you plug it in to the standard 15A outlet on the wall with no problems.

The problems start to happen when you put a 50A breaker on a circuit w/ a 30A recept, wire, and plug a 50A load in to it... I mean granted, you don't want to grossly oversize your breakers, but using a 40A welder on a 50A circuit is not going to be a big deal. Breakers don't magically trip at their stated amperage anyway, its a function of amperage and time, usually requiring 2x the rated amperage for a couple seconds before tripping.

***I don't know code by heart, but this seems to be common sense.

This is like deja vu for me. These are the exact same arguments I made. As far as the NEC goes, you and turboimpala are mistaken. Common sense just doesn't cut it for figuring out electrical code. Having a 50A load on 30A wiring in the wall is really bad. But the idea is that the device may have that 30A wiring inside it as well. If something goes wrong inside that 30A device, you are asking it to handle up to 50 Amps safely, while it was designed for 30 Amps. Now I know that the NEC does have some specific rules for welders that I really don't understand, but I am talking about the general case here. In my case I was interested in plugging a 30 Amp heater into my 50 Amp outlet. I'm not addressing what is a "big deal". I'm not telling you what to do. I'm just relaying what I was recently taught by a code following licensed electrician.

 

[turboimpala]

Actually, a TIG welder I'm looking to purchase only pulls 30 amps maximum and the instruction manual specifies the use of a 50 amp receptacle, 6 gauge wire and 50 amp breaker.

 

[trovato]

Actually, a TIG welder I'm looking to purchase only pulls 30 amps maximum and the instruction manual specifies the use of a 50 amp receptacle, 6 gauge wire and 50 amp breaker.

Right, there are reasons for that that the manufacturer has considered. And they have designed their device to safely handle a worst case 50 Amp load.

 

[turboimpala]

This is like deja vu for me. These are the exact same arguments I made. As far as the NEC goes, you and turboimpala are mistaken. Common sense just doesn't cut it for figuring out electrical code. Having a 50A load on 30A wiring in the wall is really bad. But the idea is that the device may have that 30A wiring inside it as well. If something goes wrong inside that 30A device, you are asking it to handle up to 50 Amps safely, while it was designed for 30 Amps. Now I know that the NEC does have some specific rules for welders that I really don't understand, but I am talking about the general case here. In my case I was interested in plugging a 30 Amp heater into my 50 Amp outlet. I'm not addressing what is a "big deal". I'm not telling you what to do. I'm just relaying what I was recently taught by a code following licensed electrician.

I just read the National Electric Code and I've determined that I am not mistaken. Section 210.23(A)(1) requires that the circuit rating be at least 25% greater than the equipment, and it does not specify a maximum circuit rating. Maximum circuit rating limits are only listed for special equipment, including welders. For arc welders, the circuit breaker must not be greater than 200% of the maximum rated current. This is the exact opposite of what you are saying.

 

[trovato]

How about 210-21(B)(1) where it says that a single receptacle installed on an individual branch circuit shall have an ampere rating of not less than that of the branch circuit. That means you can't put a 30 Amp receptacle on a 50 Amp circuit. The section you refer to is for 15 and 20 Ampere branch circuits, right? Are we having fun yet?

 

[turboimpala]

How about 210-21(B)(1) where it says that a single receptacle installed on an individual branch circuit shall have an ampere rating of not less than that of the branch circuit. That means you can't put a 30 Amp receptacle on a 50 Amp circuit. The section you refer to is for 15 and 20 Ampere branch circuits, right? Are we having fun yet?

No ****.
My first post stated that the circuit breaker should never exceed the rating of the wire OR the receptacle.
However, there's nothing wrong with connecting equipment that pulls 30 amps into a receptacle, wire and breaker rated at 50 amps.
I'm having lots of fun, you're just embarrassing yourself.

 

[trovato]

No ****.
My first post stated that the circuit breaker should never exceed the rating of the wire OR the receptacle.
However, there's nothing wrong with connecting equipment that pulls 30 amps into a receptacle, wire and breaker rated at 50 amps.
I'm having lots of fun, you're just embarrassing yourself.

Well, you're not going to get that 30 Amp plug to fit into that 50 Amp outlet, so you have to replace one or the other to do what you want. If you want any more information I suggest you ask an electrician. I was having fun too, right up until you decided to get nasty. Have a nice life.