Air Compressor Wiring Question

[mjperk]

I recently purchased a Quincy model 2V41C60VC air compressor. It has a 230V single phase motor with built-in thermal protection. The specs I can find on it say that it is 24A draw, but that Quincy recommends a 50A breaker. I would assume that's for inrush current, but 50A seems pretty high to me and I'm only guessing as to why they recommend that when the other manufacturers recommend 30A breakers for similar motors.

Last spring I ran a circuit for my Everlast 205SI multi-process welder/plasma cutter. The welder itself claims the maximum inrush current is 34A, and the maximum operating current is 27A. The circuit I ran for this was about 20ft - 25ft long from the panel and I used 6/3 wire. The breaker was 220V 50A and I used a NEMA 6-50 receptacle. Unfortunately for me, that circuit was the last free space in my box.

Now that I am getting the air compressor I will need to figure out how to wire it safely and easily. Since I am out of open slots in the panel and the welder outlet is in the exact same area I'd like to put an air compressor outlet, I'm wondering if it would be an okay idea to use the same branch for the air compressor and the welder. What I'm thinking is that I could put a junction box where the current welder box is and then install two more outlet boxes in that same area as well. I could then use split bolts or Polaris cable connectors to join the welder and air compressor outlet box cables to the junction box all using the same 6/3 wire I've already got in place. Doing this would prevent the need for me to install a sub-panel for a separate, new circuit or run another 25' of wire through a wall that already has a lot of plumbing and wire in it. The part I'm not sure about is if it meets Washington code (I can't find anything that talks about this sort of circuit), and if it is safe.

I won't be running the welder and the compressor at the same time a whole lot, but it could happen. The welder/multi-process tool has a plasma cutter which does require compressed air, so it is likely that the compressor would kick on at some point when I do that, but I don't use the plasma cutter very frequently. I also don't usually have the welder power turned up all the way to maximum, so the 27A maximum operating current is probably not something that it will see all the time. But I also would rather not do anything too risk.

So to highlight, my situation/proposal seems to be
-50A 220V breaker
-6 gauge wire (rated for 55A-65A?) in a 25' run
-Maximum operating current is 27A + 24A = 51A

It seems like for worst case I may be pushing it. And if the inrush amperage on the air compressor really is 50A then perhaps I would experience nuisance trips in the panel whenever the compressor kicks on.

So with all of that, is my junction box proposal a bad idea? Do need to go to the extra trouble and install a sub-panel with a dedicated circuit for the compressor?

 

[wyliesdiesels]

Thats a lot to read. However, your compressor can not be connected to an outlet based on the 24a FLA its at least 5HP. So it needs to be hardwired.

Breakers for hardwired motor circuits can be 250% max of NEC table FLC so the 50a breaker recommendation is not an issue.

Also welders are a way different beast than motors.

I would do dedicated circuits.

Can you post pics of your panel with the cover removed?

 

[sberry]

This is a 3 conductor + ground? Get a 6 space panel, hook it to the wire you have now, take the 50 put in it along with a 30 with a 10 for welder to an outlet. Put a 60 in the main. Just cause they both hooked doesn't mean they even got to be used at the same time. I have used buzz boxes on 60 with 30 to comps, doesn't mean I got to strike an arc while its running. I have never seen these 2 things, machines in these classes trip a 60, never even heard of it.
In another space would add 20 for a tool circuit, same panel. Get a ground bar kit and a big ole fat cable connector for the wire.
Just because the comp is hooked to a 50A breaker doesn't mean it draws that. I think they make a ready made equipment whip at the box stores be good for this air, all this depends on your ability with the hardware. Hook a flex with 10 to the panel if you could. The rule says its 8 for a cable. But use the same wire for the welder. This is so small if a guy had to buy a little wire by the foot it wouldn't be a deal breaker. 2 blacks and a green. A pipe or fitting like an offset to a 4x4 deep box with raised cover for the welder. They have to be a deep box for the welder recept.
As little as a foot of wire.

 

[sberry]

If that sounds confusing, yes, install a panel here. They make smaller stuff,,, don't mess with it. Get a 6 space (they do make 8 for this too) but 6 is cheap and 100A Lets a guy add 2 240V and a couple 120. So,,, is it worth it, yes and way better than something spliced in a junction box.

So with all of that, is my junction box proposal a bad idea? Do need to go to the extra trouble and install a sub-panel with a dedicated circuit for the compressor?