I want a LARGE compressor

[pharmer1]

Hi guys, my next tool purchase is going to be a large compressor. The existing wiring appears to be 10/3. I'm looking at purchasing a 60 to 80 gallon 2 stage compressor. I need to know:
1) Will 10/3 be adequate for a compressor that large?
2) The electritian put the outlet is in a bad spot, right in front of a cabinet door. What would be the best way to solve this issue. (see pics attached)
3)Why would the electrician run 10/3 rather than 10/2?

Thanks in advance, Curt

 

[FullRaceMerc]

1- That depends on the size of the motor for the compressor & the distance to the box. 10 gauge wire is typically rated for 30 amps, unless it goes over a certain distance. The gallons of the tank doesn't tell how much draw the motor uses.

2- Probably use that box as a junction with a blank cover over it, & run more wire to a better location nearby. Perhaps just higher in the same bay. And it looks like the wires enter from the top of the box, so you might be able to find them higher in the same bay.

3- Some equipment uses a neutral, so 10/3 makes sense just in case. If your receptacle is 3 wire, wire nut off the neutral in case it is needed later. The cost difference between 10/2 & 10/3 makes it silly to run 10/2 compared to the cost of labor to make a change later.

 

[CNGsaves]

Location, location, location !!

That 240v outlet is terrible location for 60 gal compressor. You will want compressor off in corner where it won't be in the way. Also, the distance will be benefit so your airline system can run up towards ceiling and around to where you will actually use the air. This distance allows air to cool and drop out moisture. Recommend black pipe steel or copper for airline system.

Recommend you plan on using that 240v outlet for welder or some other purpose. Run a new 240v circuit to where the compressor will actually go. Good luck.

 

[jmilch]

Just look at the amp draw of the motor, not the HP rating, as many manufacturers rate the motors differently.

For 10 guage, you are good up to 30 amps. Any decent 5 HP single phase motor will be rated for 20-22 FLA. A plug receptal is not recommeded and in some cases against code. So you will want your compressor hard wired if possible, which may require some work.

You will find a 80 gallon vertical tank takes up a bit more space than a 60 gallon. For space retrained applications I would look for a 60 gallon. Air capacity is just that, it does not increase CFM or performance, that all comes from the compressor pump.

 

[Mustang51js]

Did you tell him to put outlet in that area,I can see it being ok if the compressor goes where you have the cabinets,where do you plan on putting compressor in relation to the outlet box now

 

[pattenp]

Just look at the amp draw of the motor, not the HP rating,

When wiring per NEC you need to use the HP rating from the motor data plate and use the NEC 430.248 table to get the FLA. 28 FLA is to be used for motors listed as 5HP. So the circuit needs to be sized at (28X1.25) or 35Am

Edit: Plugs and outlets such as 6-30 and 6-50 are rated to 3HP. Over 3HP you should hardwire the compressor.

 

[Norcal]

Based on the Federal Pioneer panel, I would say the OP is in Canada, NEC not relevant.

 

[pattenp]

Based on the Federal Pioneer panel, I would say the OP is in Canada, NEC not relevant.

How true, I didn't think much about the panel. That's why it's so important to have even just the country location in your profile. Well maybe my reply has some relevance to jmitch, but I don't know his location either.

 

[tfi racing]

Based on the Federal Pioneer panel, I would say the OP is in Canada, NEC not relevant.

This is true,but the NEC and CEC are merging closer every edition,especially in the residential rules.That is a silly spot to put that box,no idea what they were thinking,they used 10/3 because every loomex jockey has it on the truck,10/2 NMD90 is just not popular and can be hard to find in some areas.

 

[pharmer1]

Great, I'm looking at a used 80 gallon with a 5hp motor with an amp draw of 25.5 amps. So the 10/3 will be adequate with a 30 amp breaker?

Now I just have to figure how to deal with the placement of the outlet.

 

[Mustang51js]

Put a 1900 box extension and run a pipe to where you want the outlet

 

[pharmer1]

Put a 1900 box extension and run a pipe to where you want the outlet

Good idea. Then all I would need to do is put a cover plate over the box extension and run 10/2 to the desired location. I'm only going approximately 5' around the corner, would it be better to use BX cable or metal conduit?

 

[wyliesdiesels]

While I realize the OP is in Canada, NEC code sizes wire for motors @ 125% of NEC table FLC. This means that #10 NM-b is good for upto 3-4HP motors. A 5HP motor is listed @ 28a which equals 35a wire...of course the CEC is probably different...

 

[Norcal]

While I realize the OP is in Canada, NEC code sizes wire for motors @ 125% of NEC table FLC. This means that #10 NM-b is good for upto 3-4HP motors. A 5HP motor is listed @ 28a which equals 35a wire...of course the CEC is probably different...

If it was THHN in conduit, providing provisions in NEC art 430 were met 10 AWG is rated for 35A. CEC regulations apply though.

 

[Mustang51js]

Good idea. Then all I would need to do is put a cover plate over the box extension and run 10/2 to the desired location. I'm only going approximately 5' around the corner, would it be better to use BX cable or metal conduit?

I would use pipe with an lb to get around the corner,and now that I look at the screw location,it looks like a 4-11/16 box not a 1900 box. So just get the appropriate extension,1/2 emt and your set

 

[wyliesdiesels]

If it was THHN in conduit, providing provisions in NEC art 430 were met 10 AWG is rated for 35A. CEC regulations apply though.

Yes Im aware of that. I was referring to NM-b wire NOT THHN, since the OP already has NM-b wire...

 

[7echo]

Depending on the wall you could possibly go out the other side of the wall. Put a cover on that box and run a ****** to the new box directly behind.

If that makes sense...