Compressor hook up .

[sphelps]

Finally getting around to hooking up my new 80 gal compressor .. I have 3 big rubber vibration feet feet to mount to the slab . Getting the oil for it and need to get the wire to hook into a 60 amp service I have for it .. It says to use 14/10 AWG wire . 5 hp single phase motor 240 volt .
Just not sure what size breaker to get .. Not the sharpest on this stuff so any help would be appreciated ..
I want to get it up and running then figure how I want the supply set up ..

 

[bruceb58]

If it's a 60A outlet, you want a 60A breaker. The wiring from the breaker to the outlet is going to be way bigger than 14/10. Going to be likely 6 for the hots and something a little smaller for the ground. Depends on how far the outlet is to the breaker.

You already have the outlet wired? Not clear to me since you were asking about the size of the breaker.

 

[HT32BSX115]

new 80 gal compressor .. I have 3 big rubber vibration feet feet to mount to the slab .
Just not sure what size breaker to get .. Not the sharpest on this stuff so any help would be appreciated ..
I want to get it up and running then figure how I want the supply set up ..

I have a similar Compressor. Mine is 5hp, 80gal (Home depot) I used a 30A breaker and #10 wire (10-4)

Why do you want 60A service? Are you plugging a welder into that outlet too? (I used a 70A breaker for my Miller Synchrowave 180 using a different outlet)

 

[sphelps]

Yes it's a 60 amp service that powers a welder also .
The plate on the motor reads 22.5-22.0 amps
So feeding from panel 10 ga wire with a 25 amp breaker .
Does that sound right ?

 

[HT32BSX115]

Yes it's a 60 amp service that powers a welder also .
The plate on the motor reads 22.5-22.0 amps
So feeding from panel 10 ga wire with a 25 amp breaker .
Does that sound right ?

Mine says 22A also......I used a 30. A 25 might trip during startup

 

[dwco5051]

Mine says 22A also......I used a 30. A 25 might trip during startup

I say go with the 30 amp. That is the limit for #10 wire and will reduce start up trips. The NEC allows a breaker for a motor to be up to 250% of the running load providing the conductor is properly sized. I have been away from this stuff for many years now and at least that was what it used to be.

 

[MTboatguy]

I am running mine actually on a plug in cord that has the same plug set up as my welder and it is a 50A circuit and the cord I wired up is 4 gauge wire for welders. Been running this way for over 5 years now with no problems at all, cord never heats up and it puts all the air I need out of it.

 

[sphelps]

Got it running used the 25 amp breaker .. If I have trouble I will switch to the 30 ... Can't believe how quiet it runs ... The shroud has a small rattle to it so I will need to adjust that ... Now it's time to figure the air supply ... Was thinking on making a series of loops with drain valves at the bottom of the loops . I saw that somewhere and thought it might be a good idea along with a water filter .. Can't wait to get it ready for painting ...

 

[HT32BSX115]

Got it running used the 25 amp breaker

If it doesn't trip when it restarts after bleeding down, it probably never will....

 

[dwco5051]

If it doesn't trip when it restarts after bleeding down, it probably never will....

Yep. Don't know if your compressor has the unloader so it doesn't have to start against pressure or not but you probably will be OK. Circuit breakers are a little more complicated than they seem. They will shut off instantly if the current is more than 135% of rating. Less than that there is a delay as to how long they will stay on that is inversely proportional to the current to make up for the surge of current when a device is started. There are charts that give the "trip curve" of a given breaker but you have to be almost an electrical engineer to read them. Start painting!

 

[bigdee]

Breaker is should be sized large enough to handle start current. Compressor motor has built-in thermal protection which protects the motor from overloads. Since #10 AWG makes it a 30 amp branch circuit I would go with a 30 amp breaker.

 

[bruceb58]

I am curious what your outlet looks like. Have a picture?

 

[bigdee]

Yes it's a 60 amp service that powers a welder also .
The plate on the motor reads 22.5-22.0 amps
So feeding from panel 10 ga wire with a 25 amp breaker .
Does that sound right ?

Why not put a welder plug on the compressor and just plug it into the welding outlet? Use 10/3 SJ cord for the pigtail from the compressor. This is acceptable by NEC.

 

[bigdee]

I
You already have the outlet wired? Not clear to me since you were asking about the size of the breaker.

My thoughts too.....just use the 60 amp outlet!

 

[dwco5051]

My thoughts too.....just use the 60 amp outlet!

I took this that he had a 60 amp sub-panel in his shop or garage fed from the house.

 

[bruceb58]

My thoughts too.....just use the 60 amp outlet!

If he does have a 60A outlet, is it code to have a 30A breaker driving it or is it acceptable since the purpose of the breaker is to protect the size of the wire?

I installed 2 60A outlets in my garage and it was my understanding code required the breaker and wiring to be able to supply what the outlet was rated for. My welder and plasma cutter take no where near 60A but they use the 60A plug.

 

[bigdee]

If he does have a 60A outlet, is it code to have a 30A breaker driving it or is it acceptable since the purpose of the breaker is to protect the size of the wire?

No code says 60 amp breaker is fine as long as branch circuit to receptacle is sized for 60 amps. The compressor can have #10 wiring plugged into 60 amp welder outlet because the thermal overload built into the motor protects the #10 wire from overload. Read NEC article 430.

 

[bruceb58]

No code says 60 amp breaker is fine as long as branch circuit to receptacle is sized for 60 amps. The compressor can have #10 wiring plugged into 60 amp welder outlet because the thermal overload built into the motor protects the #10 wire from overload. Read NEC article 430.

Correct...I understand that part about 10 gauge up to the outlet from the compressor.

So now from the breaker side...So it's ok to have 10 gauge from a 30A breaker to a 60A outlet? Is the outlet required to have a label saying 30A max?

I haven't looked at the NEC code you just quoted...going to look at that now

 

[sphelps]

I am curious what your outlet looks like. Have a picture?

No outlet if your talking about the electrical hook up ... It's wired strait into a sub panel box ..

 

[sphelps]

If it doesn't trip when it restarts after bleeding down, it probably never will....

I cycled it several time with no tripping