New Jointer electrical question

[brian cammarata]

Howdy folks, I forgot to sleep at a Holiday Inn Express last night so my electrical knowledge is a bit lacking. I think this is simple issue but wanted to test waters with forum knowledge base first.

In my workshop / space, where I want this 8" jointer to go, I currently have it wired for my 5hp dual drum sander, with a a L6-30R on a 30 amp breaker in my box. My new grizzly jointer G0856 came with 6-20 plug. Can I just cut that plug off and put a new L6-30P plug on that?

Is there any detriments on powering the jointer on a bigger circuit / plug than recommended?

Thanks in advance, as I am probably over thinking this

-Brian

[Ron Selzer]

Go for it, will be fine

[Mike Cutler]

Nope, you’re good. The NEC stopped at the receptacle.
There are millions of electrical devices pulling less than the amperage the supply breaker is rated for.

[Bill Dufour]

make sure the motor is wired for. 240 volts. With that plug i assume it is.
Bill D

[Cameron Wood]

I would replace the receptacle with one that fits the jointer, and save the other one for use with the sander. Much cheaper.

[Phil Gaudio]

I would replace the receptacle with one that fits the jointer, and save the other one for use with the sander. Much cheaper.

Receptacle has to be rated for the wiring in the house, so putting a receptacle rated for 20 amps on a branch circuit rated for 30 amps would not be a good idea.

[Justin Rapp]

Receptacle has to be rated for the wiring in the house, so putting a receptacle rated for 20 amps on a branch circuit rated for 30 amps would not be a good idea.

yup I agree with this. But it's easy enough to replace the plug on the jointer to a L6-30R so either machine will work. The jointer, while only requiring a 20amp circuit will work fine on a 30 amp circuit. Same idea as running an 8 amp blender in the kitchen on a 20 amp GFI circuit.

[Greg Funk]

The breaker should be a maximum of 250% of the FLA of the motor on the circuit (NEC table 430.52). In your case if the FLA is 12 the max breaker size is 30A so you should be OK.
Change the plug on the jointer to match the receptacle.

[Cameron Wood]

yup I agree with this. But it's easy enough to replace the plug on the jointer to a L6-30R so either machine will work. The jointer, while only requiring a 20amp circuit will work fine on a 30 amp circuit. Same idea as running an 8 amp blender in the kitchen on a 20 amp GFI circuit.

Household outlets including GFCI are generally 15 amp rated devices on 20 amp circuits these days, and that blender probably has #16 or smaller power cord wires- same deal with the jointer.

[Justin Rapp]

Household outlets including GFCI are generally 15 amp rated devices on 20 amp circuits these days, and that blender probably has #16 or smaller power cord wires- same deal with the jointer.

yes correct - I worded it a bit off - 20 amp circuit with 15 amp gfci protection.

[Doug Colombo]

They sell an adapter that will cover your issue - I can post a picture of it when I get home.

[Cameron Wood]

yes correct - I worded it a bit off - 20 amp circuit with 15 amp gfci protection.

My point was that hooking up the jointer with a 20 amp receptacle on a 30 amp protected circuit is equivalent to common household 20 amp circuits using 15 amp rated receptacles.

[Bill Dufour]

A quality 240 volt machine will have onboard overloads to protect the motor.
Note that most home breakers will interrupt a maximum 10,000 amps. more then that and they can not disconnect it just arcs across the open terminals.
Saw the after effects when a 12 KV overhead line dropped onto a 120 supply line. Blew open the door of the fuse box in the attic. glass fuse and melted copper flew out some where into the junk in the attic, very lucky no fire.
Bill D

[Doug Colombo]

Here are some pics of the adapter. With this you should not have to cut off / replace any plugs.

image1.jpg image2.jpg image0.jpg

[glenn bradley]

It is easy enough to swap either plug or receptacle, your choice. I believe your question is directed at the circuit. Your circuit and device (read outlet) are spec'd for 30 amp service. As Mike mentioned, NEC stops at the 'device' (read outlet). The breaker protects the line and device (read outlet), not your machine. If you plug a lower capacity machine into a higher capacity outlet it simply means that the circuit protection is possibly beyond the capacity of your machine. Your machine probably has a breaker or fuse to protect the motor. In practice, and I am a careful spec follower, I would probably change the plug and use the circuit as is. I would remain conscious that I have a 20 amp machine plugged into a 30 amp circuit but unless I have a questionable power plant I would not be overly concerned. If you routinely blow breakers or suffer slow-downs or brownouts I would make things right. That is, the condition of your overall infrastructure comes into play. If it is solid my concern is minimal.