240V Sockets / Plugs & Uses

[TheJeepNut]

So I've got a "Member of the Shadetree Electricians Union" hat that I'm wearing this week.

Just got this awesome new compressor.  Much larger than my previous tire pump and needs 220-240.

 

I've got two 240 circuits shown in the box.

One is a pair of ganged 20amp breakers that goes to a socket in the diningroom as well as to a bedroom.

The shape of the wall socket is the 20 amp  -.- shape in both rooms.  I think the PO ran them for a tanning bed for the wifey.

 

The other is a pair of ganged 40amp breakers but I've never found that they power anything.  They may just be stuck in the box and not utilized.

 

But this compressor needs min 22amps.  So I was going to set it in the garage and run a 25ft extension cord to the dryer outlet in the adjacent utility room.  I'm a single guy now and I don't use a dryer much so, meh... should work fine right?  I know the dryer runs ganged 30amp breakers and the door out to the garage is always open because it's heated and cooled anyway.

So here's the problem:

 

1.   I'm looking at the plug ends at the local HW stores and not one of them has just a loose plug that fits this dryer socket.

2.  In the research I'm seeing that Dryer cords that are available off the shelf have the two slanted 120 lines but that return line has a L shape to it as does my dryer's wall socket.

3.  RANGE cords that are off the shelf items are also 30 amps and have the two slanted 120 lines but have a ROUNDish hole for the return.

4.  No matter if you buy a Dryer cord or a Range cord, they're not locally available longer than 6' and I need 25'.  At least for a while.

 

So this all tells me that I may be trying to do something ill advised. 

But I'm not convinced and I don't get WHY the hole for the return lug would be different for a dryer vs. a range if both operated at 30 amps.

I do understand that there are 3ph vs. single phase considerations but the compressor is a single phase unit.

Shouldn't a simple dryer motor also be a single phase?  I think they need the 30a 220 mostly for the heat.

 

I'm poking around online now to try and find just a plug but 25' of 10/3 rubber cable is $75 here locally.
I don't want to blow $100 to build a cord that's gonna jack up the new compressor OR burn down JeepNut's Garage...

 

Whose our electrician here?

 

 

 

[Dzimm]

You are very unlikely to find a pre-built cord that is 25' long.  It's just generally a bad idea to have that much exposed cord with that much power in it.  You can make your own but it won't be cheap as you said.  It doesn't necessarily create a fire hazard unless the cord gets damaged, but then I'd be more worried about getting electrocuted.

 

Another option is to plug your compressor in by the dryer and get a longer airline to run outside until you can get the circuit installed.

[Pete M]

nothing beats running a dedicated new breaker and a box in the garage right where you need it.   

[mjeff87]

Me and 'lectrical stuff do not get along, at all.  I have a healthy respect for voltage (and amperage).

 

I bribed an electrician buddy of mine to run spare outlets for me in my garage for just this purpose.  You'd be surprised what a case of beer and a couple pounds of lunchmeat will get ya, from the right person.  LOL.

 

 

[BeatCJ]

Easiest, cheapest, safest is to do like Pete M is saying. If your 40 amp circuit is not used, wire from that. How far from your panel to a good place to plug in the compressor?

Edit:

Trying to guess from your post, but I think this plug might work: https://www.weldingandcutting.com/Crowfoot-Style-Plug-50-Amp-p/KH529.htm?gclid=Cj0KCQjw8fr7BRDSARIsAK0Qqr7nYBzev9Ti1Mlm-BlsKscfHQpmaR1Hp1yF8veXVryz22pIcvzMWosaAl3FEALw_wcB

It has interchangeable blades for the Neutral/ Ground

Edited October 8, 2020 by BeatCJ
added info

[TheJeepNut]

Thanks all. Was hoping for something fast to get the new compressor compressing but as with everything it drags on and on it seems.

Having to get the new compressor has delayed work for 4 weeks now.  sigh.

 

On 10/8/2020 at 1:31 PM, BeatCJ said:

Trying to guess from your post, but I think this plug might work: https://www.weldingandcutting.com/Crowfoot-Style-Plug-50-Amp-p/KH529.htm?gclid=Cj0KCQjw8fr7BRDSARIsAK0Qqr7nYBzev9Ti1Mlm-BlsKscfHQpmaR1Hp1yF8veXVryz22pIcvzMWosaAl3FEALw_wcB

 

That WOULD work I suspect but at this point I've decided to run a dedicated 30amp line in conduit. 

I happened to have enough lengths of 3/4 to do the runs but needed some 90's.  

Found all but ONE 3/4 elbow by luck as neither Menards or Lowes has squat for the grey 3/4 Corlon conduit connectors/adapters.

LOTS of 1"+ or 1/2"  but not 3/4...  I pulled boxes and looked in the wrong ones, etc and not one single 3/4" 90 degree curve left in either store. 

 

I'm going to just get the cable through and hang what I've got and just leave one end unfinished for now.  

Won't be code but I don't live with a CE officer.  It'll do for me for now.

Thanks for all the feedback tho!

[BeatCJ]

Cable? If you are talking a multi wire conductor with a sheath like Romex it's not intended to be in conduit. I believe the extra layers of insulation can make it overheat. I could be wrong, and you should check with a real sparky, but that's what I remember.

 

If you are surface mounting, it should be in conduit, but you should have individual conductors.

[Dzimm]

14 hours ago, BeatCJ said:

Cable? If you are talking a multi wire conductor with a sheath like Romex it's not intended to be in conduit. I believe the extra layers of insulation can make it overheat. I could be wrong, and you should check with a real sparky, but that's what I remember.

 

If you are surface mounting, it should be in conduit, but you should have individual conductors.

I don't believe it's in the NEC code not to run romex trough conduit.  But you are correct it is due to the heat issue that people shy away from it.  If the conduit is properly sized you wouldn't have an issue and should absolutely be in conduit if it's in an unprotected area such as on the outside of a wall.  

 

As you mention, it is generally best to run individual conductors through conduit.