220/240v air compressor install

[egobuster1]

Alright i don't have pictures to explain but i have a sub panel in my detached garage that appears to have the incoming wires coming into a dual 60 amp breaker then after that there 4 empty spaces and next to that is a single 15 that has my light and outlet ran off of it.

so i'm wondering am i good to add in a dual 20 amp for my 220 and use Romex 10-2 to run it to a outlet behind my new compressor.

 

[Rock knocker]

Sight unseen, but given as you describe it, the answer should be yes. Just make sure the in infeed is properly sized for 60A.

 

[egobuster1]

i believe it is, it was installed by a licenses electrician and was approved with a county permit when don't and the wire feeding the 60 amp breaker is a big wire!

 

[wyliesdiesels]

The key missing info is the HP rating of the compressor.

 

[egobuster1]

It's 7.5 I believe. I just went with 20amp because the guy I got it from had a electrician wire it in and he use 20 amp and the guy said he never had a problem with it

 

[Rock knocker]

Now there might be a problem

 

[md21722]

You need to tell us the HP of the motor and the amps on the motor. If it is a true 7.5 HP then it will need to be wired for 50A, so #8 THHN (in conduit) or #6 NM-b (Romex). If he was running on a 20A before it is more like 3HP with some fake advertising.

 

[wyliesdiesels]

It's 7.5 I believe. I just went with 20amp because the guy I got it from had a electrician wire it in and he use 20 amp and the guy said he never had a problem with it

No way would a true 7.5HP motor run on a 20a breaker without tripping it. FLC is 40a.

 

[egobuster1]

It could be 5hp then. It says both on it and I didn't to close attention to it. I just checked the CFM to meet my needs and it did

 

[egobuster1]

Well I can't look at the tag right now but looked up the new version of my compressor that's offered and they rate it at 24 amps. Do I go 30 or do I need bigger

 

[egobuster1]

Is this bar acting as both the ground and the neutral bar?
Or in simple terms am I ok to wire my ground (green) into this bar

 

[Rock knocker]

Or in simple terms am I ok to wire my ground (green) into this bar

No, not on a sub panel. You will need a hold down kit for back-fed 60A feed, and a ground bar which will be bonded to the chassis.

The ground and the neutral are only connected at the service entrance of the house.

 

[egobuster1]

Are you able to link me to this hold down kit or something. I have no idea what that is. As for the ground bar where would I install that

 

[Rock knocker]

I guess I should back up a second. I am assuming that the neutral bus is not bonded to the chassis, that is how it appears. But with the wires disconnected from the bus, and the power off, you should check for continuity between the bus and the ground.

 

[Rock knocker]

Use this type of bus if there is in fact continuity between the existing bus and the chassis, and now land all your neutrals here

 

[Rock knocker]

If the existing bus is in fact isolated from the cans chassis, the leave the neutrals there and land the ground wires on a bus like this, installed solidly to the can by yourself in a convient location.

 

[Rock knocker]

A hold down will look something like this, and be made specific for you panel and breakers

 

[egobuster1]

Alright it looks as if the neutral bond screw has been removed. I looked up the model of my box and it talks about removing that binding screw and it's gone.
So now I found the part number for the ground bus but how do I ground it? Do I just move the ground coming from the house over to that bar?

 

[bobmulry]

Is this bar acting as both the ground and the neutral bar?
Or in simple terms am I ok to wire my ground (green) into this bar

Looking at your box it seems that they only pulled 2 hots and a neutral but no ground????????????????????????????????

I thought that you would need a dedicated equipment ground with a separate neutral & ground buss bar (not tied together)

Bob

 

[egobuster1]

There 4 wires coming in. Black and red going to the 60 amp breaker and a white going to that top right post and then the green wire going to the bus bar.
I think the green is the ground?

 

[wyliesdiesels]

It could be 5hp then. It says both on it and I didn't to close attention to it. I just checked the CFM to meet my needs and it did

Well I can't look at the tag right now but looked up the new version of my compressor that's offered and they rate it at 24 amps. Do I go 30 or do I need bigger

That would be a 5HP motor. 5HP FLC is 28a.

A 20a circuit is too small for that.

Need #10 THWN in pipe or #8/2 NM-b. Disconnect is required if not within sight of panel and further than 50'.

Is this bar acting as both the ground and the neutral bar?
Or in simple terms am I ok to wire my ground (green) into this bar

That panel is setup incorrectly. Whoever wired it didnt know what they were doing.

Heres a pic:

Its 4-wire fed and Neutral bar is isolated but the EGC/ground wire(green) is going to the same bar. This wire should be on a separate bar screwed directly into the panel. All ground wires should be on this new bar.

And as has been mentioned, that main breaker, needs to have a hold down screw/kit.

However, u will have 6 or less breaker handles so a main breaker isnt required. They are nice to have though.

Alright it looks as if the neutral bond screw has been removed. I looked up the model of my box and it talks about removing that binding screw and it's gone.
So now I found the part number for the ground bus but how do I ground it? Do I just move the ground coming from the house over to that bar?

Yes move the green wire over to this new bar.

There should be some prepunched holes in the can. U use the self taper screws that come with the bar to mount it.

U also need 2 ground rods.

There 4 wires coming in. Black and red going to the 60 amp breaker and a white going to that top right post and then the green wire going to the bus bar.
I think the green is the ground?

Correct. Read above

 

[egobuster1]

Yeah I'm getting the ground bar and the grounding rod and gonna move the grounds over and put in the new 30 amp breaker

 

[Rock knocker]

Wylie is a real electrician, and you should always do exactly what they say if their advice is even slightly contrary to a non electrician like myself.