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All Replies on I have a 240v 40 amp oulet in my garage/shop

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View nik_nak's profile

I have a 240v 40 amp oulet in my garage/shop

by nik_nak
posted 10-29-2018 01:24 PM


11 replies so far

View HokieKen's profile

HokieKen

8600 posts in 1435 days


#1 posted 10-29-2018 01:27 PM

You can replace the 40A breaker with a 30A without replacing the wire if that’s your question. As far as multiple outlets on a single circuit, I believe it’s permitted by code but generally frowned on.

-- Kenny, SW VA, Go Hokies!!!

View MrRon's profile

MrRon

5364 posts in 3540 days


#2 posted 10-29-2018 01:42 PM

30 amp at 240v sounds like a lot of power for the typical home shop bandsaw. Thats equivalent to 60 amps at 120v. I would split it into 2- 20 amp circuits. One 20 amp circuit should be plenty to handle a 1-1/2hp bandsaw and a 2hp DC.

View bmerrill's profile

bmerrill

45 posts in 370 days


#3 posted 10-29-2018 03:47 PM

A breaker is sized to protect the wiring and does not reflect the AMP draw of the connected equipment.

It is not advisable to run (2) 30AMP tools on a 40 amp circuit at the same time. Please verify the actual power requirements of the equipment.

Typical 240v shop tools required a dedicated 240V/20amp circuit utilizing (6-20) NEMA connector. There is nothing saying you cannot have several convenient outlets on the same circuit but you should limit the circuit to only one tool at a time.

In my recent project of rewiring the attached 2 car garage for the newly acquired 240 volt table saw and bandaw, the duplex receptacles were split wired where the top outlet is on one circuit and the bottom on another with these receptacles spaced at locations where the tools maybe used. Since this is a shared use space the tools are all mobile.

Disclaimer: It is best to discuss electrical needs with a qualified electrician who can lay eyes on the project.

-- "Do. Or do not. There is no try". Yoda

View nik_nak's profile

nik_nak

3 posts in 143 days


#4 posted 10-31-2018 11:04 AM

Yes, I meant to say 20 amp, sorry. Thank you for the advice. I think we are going to sell in the next couple years and just trying to do what I can without wasting money.

View Jared_S's profile

Jared_S

133 posts in 256 days


#5 posted 10-31-2018 11:55 AM

I’m not suggesting this, but I have 6 240v outlets on 2 30a circuits. It works fine for me because I only ever run one machine at a time.

View TheFridge's profile

TheFridge

10844 posts in 1783 days


#6 posted 10-31-2018 12:20 PM

The receptacles should be rated with the same amperage as the breaker.

Multiples on one circuit? Technically? I think no? This can of worms had been opened so many times I’ve forgotten. I have 2 tables saws and a jointer on the same 20A ckt. May not be legal but it’ll work just fine.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View bmerrill's profile

bmerrill

45 posts in 370 days


#7 posted 10-31-2018 12:39 PM



Yes, I meant to say 20 amp, sorry. Thank you for the advice. I think we are going to sell in the next couple years and just trying to do what I can without wasting money.

- nik_nak

With the correction you can run 2 20amp 240 Volt circuits for the termination of the 40amp circuit.
Treat the 40amp circuit as a sub-feed; at its terminus, install a 4-8 space 240Volt sub panel. In the sub panel remove any bonding between the ground and neutral.
From there feed your 2 new circuits. 20amp 240 volt requires 12/2 with ground for each circuit.

-- "Do. Or do not. There is no try". Yoda

View Robert's profile

Robert

3315 posts in 1777 days


#8 posted 10-31-2018 01:19 PM

Its always best have your DC on a dedicated circuit.

But yes, you can run multiple 220V machines on one circuit. I’ve been doing that for 25 years with never an issue and on many occasions mulitple machines running at once. Doesn’t mean its right and it may not be code, but that’s my electrician told me it ok.

And that’s my point [cut and paste] CONSULT AN ELECTRICIAN, NOT A FORUM. Even if its not 100% “code” he can tell you what you can/cannot do.

-- Everything is a prototype thats why its one of a kind!!

View TheFridge's profile

TheFridge

10844 posts in 1783 days


#9 posted 10-31-2018 03:46 PM

Electrician here :)

Sticky subject between NEC and building codes.

Although a slightly different angle, if multiple 20A 250V receptacles weren’t allowed on a circuit, then there wouldn’t be a duplex 20A 250V device UL listed and available for purchase.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View jonah's profile

jonah

2035 posts in 3595 days


#10 posted 10-31-2018 03:54 PM

I believe you can have more than one 20A receptacle on a 240V circuit, but that higher draw receptacles are single per circuit only.

Most 240V machines aside from welders are fine on 20A outlets, so it can definitely work to put three or four of those on a single circuit.

View nik_nak's profile

nik_nak

3 posts in 143 days


#11 posted 11-02-2018 04:15 AM

Thanks for the help everyone. I might just run the DC off this circuit and wire the bandsaw to 110v.

I know (or think I know) you can run 15a 110v outlets on a 20a circuit.

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