What size circuit breaker for grinder?

R

Ricky-O

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Oct 30, 2021
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I have a Leeson motor on my grinder running at 220v. Currently I have it plugged into a 30 amp outlet, but I'd like to have an electrician install an outlet closer to where I'd like to grind. So I'm wondering how many amps the circuit would need to be (I know I'd have to change the plug if it isn't 30 amp). My motor is:
Cat. No: 1110076.00, Model: C6T17FK140A, FLA: 5.8, HZ: 60
Not really knowing anything about electricity, I'm wondering if a 15 or 20 amp circuit would be sufficient? Or would it be better to stick with a 30 amp circuit?
 
Thanks. I'm going to keep the 30 amp outlet other side of the garage, which I could use for a welder or oven, and basically am wondering about an additional circuit. But since I already have a 30 amp plug on my grinder, it's probably easiest to make the circuit 30 amp also.
 
I can tell you from experience that you can't have too many 30 amp 220 outlets in a shop. They are very useful for knife shop type equipment.
 
Seedy Lot said:
Remember it is not only about the breaker but the size of wire running from the breaker. Many fires start because of insufficient wire size running from a larger breaker.
Click to expand...
Agreed
The breaker Just protects the wire.
 
You can put an extra fuse in line with the motor if you're worried about it, after the plug. it's a 1500w motor, so only draws ~7amp at 220v, although you need to worry about startup current so 15amp
 
Last edited:
People often confuse a circuit breaker with a protection fuse/breaker.
Circuit breakers are sized to the wiring going from them to the receptacle(s). Their job is to protect the wires in the case of a major short circuit. They are not sized to the tools or things attached to them. If that was trye you would need 1amp breakers for a lamp and such. Their job is to limit the TOTAL allowable current through that circuit.
Protection fuses and breakers are installed on the tool or appliance and are rated at the maximum current the device will draw. They may range from less than an amp on delicate electronics to more 30 amps on large tools. They are generally a red button or switch marked "RESET". Their job is to trip when the device draws too much current and thus protect the motor windings or electrical/electronic parts. They are there for protection from and internal short or other device failure, overcurrent due to a motor stalling, or overcurrent due to start-up current spike.
The size of the breaker that runs the plug has no effect on them unless the tool draws more normal current that the circuit breaker will deliver.

Receptacles need to be rated for the size of the breaker that runs that circuit, too. A NEMA chart will give you the correct size plugs and receptacles for any amperage circuit.
1726220629777.png

Wire size and breaker size charts can be complicated by distance and temperature, but a good rule of thumb is this:
1726221169420.png
 
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