circuit size for air compressor

[mr_future]

I'm running a 240V circuit to the garage for an air compressor (which I don't have). While a 30 amp circuit would probably be enough, I might upgrade in the future, or decide to run a welder from that circuit (not at the same time). Is there anything wrong with installing a circuit that is too big for a device? If not, I might go for something like 50 amps...

 

[Sycan]

Running bigger wire is fine, but use appropriate sized breaker for the intended use. Don't use a 50 amp breaker if the compressor only needs a 20

 

[pattenp]

Also a 50 circuit will require a 50A rated outlet. Even if the wire is rated for 50A and you use a 30A outlet, the breaker needs to be no more than 30A.

 

[mr_future]

Have been thinking and googling about it. A - I think I am overestimating the amount of power I will ever need. B - in the rare event that I get to buy some expensive device that requires a 50 amp circuit, it wouldn't be too hard to cut out some drywall to wire the new circuit/outlet.

 

[sberry]

No, there is nothing wrong with going for 50A (Except maybe cost.) The breaker protects the wire, not the device, so as long as you have 50A capable wire on a 50A breaker, you're good to go.

Not on this type of circuit.

 

[ByGeorge]

If it was me, I would bring your 50 amp 240 volt "four wire" circuit to a sub panel inside your garage/ shop. (sub panels are cheap) That way you can do whatever you want from there.
Install your 30 amp 220 for your compressor, along with some 20 amp. 120 volt receptacle circuits.
In theory the 50 amp ckt. will work on a 20 amp. rated tool, but have you ever tried to install a #6 wire on a device that will only accept a #12 wire?

 

[rburke65]

Run a 60 amp. circuit and set a sub panel the you will be covered.

 

[nadogail]

I put in an appropriately protected 50 Amp circuit for my stick welder, then later added a 5KW electric heater to the same circuit using what I call the "10' tap rule".

My 10 Gauge tap conductors are run from the welder receptacle to a 30 Amp fused disconnect , and from the disconnect to the heater.

This works for me because my welding is infrequent and my desire for added warmth in the garage/workshop is only occasionally.

Your individual results may vary and my advice is guaranteed to be worth exactly what you paid for it.

 

[wyliesdiesels]

I'm running a 240V circuit to the garage for an air compressor (which I don't have). While a 30 amp circuit would probably be enough, I might upgrade in the future, or decide to run a welder from that circuit (not at the same time). Is there anything wrong with installing a circuit that is too big for a device? If not, I might go for something like 50 amps...

The problem is motor circuits are a different animal.

wire size is based on HP.

yes u can put in a 50a circuit and hardwire the compressor.

If the compressor is over 3HP it would need to be hardwired anyways which makes using the circuit for welder difficult.

A subpanel as suggested above is a better idea.

Running bigger wire is fine, but use appropriate sized breaker for the intended use. Don't use a 50 amp breaker if the compressor only needs a 20

that all depends on the compressor as motor circuits are different and the breaker feeding them is NOT designed to protect motor or wire.