220v woodworking equipment and EV charging on the same outlet?

[Aaron Heck]

I think the answer to this is no, but I just wanted to check.

We just moved into a new house and I need to have an electrician put in a 220v circuit for the table saw, etc. I think this is commonly probably a 30 amp circuit.

I am also getting a Hybrid vehicle and while I'm not sold on a level 2 charger yet, I'd like to keep that option open. But...I think many of these level 2 chargers can go up to 50 amps. However, the Wrangler I'm getting maxes out at 32amps but I'm thinking about future proofing.

I think either way you go would be bad - plugging in the saw into a 50amp outlet would be dangerous and plugging in an EV charger to a 30 amp circuit would flip the breaker. So is the only option to really have 2 separate curcuits? that's fine, I was just trying to keep the electrical costs to a minimum.

thanks!

[Mike Henderson]

I think the answer to this is no, but I just wanted to check.

We just moved into a new house and I need to have an electrician put in a 220v circuit for the table saw, etc. I think this is commonly probably a 30 amp circuit.

I am also getting a Hybrid vehicle and while I'm not sold on a level 2 charger yet, I'd like to keep that option open. But...I think many of these level 2 chargers can go up to 50 amps. However, the Wrangler I'm getting maxes out at 32amps but I'm thinking about future proofing.

I think either way you go would be bad - plugging in the saw into a 50amp outlet would be dangerous and plugging in an EV charger to a 30 amp circuit would flip the breaker. So is the only option to really have 2 separate curcuits? that's fine, I was just trying to keep the electrical costs to a minimum.

thanks!

It is not at all dangerous to plug the saw into a 50 amp outlet. You could plug it into a 1,000 amp circuit and it would be very safe. The breaker is there to protect the wire, not the tool.

Remember that an EV will only draw 80% of the circuit's rated current, so on a 50 amp circuit, the EV will only draw 40 amps.

If you plug the EV into a 30 amp circuit (and tell the EV it's a 30 amp circuit) it will only draw 24 amps.

Mike

[Aaron Heck]

ok, I think I can understand what you are saying about the breaker protecting the wire. But if this is the case, why not make all of the runs in the house have very high amp breakers? If there's no fear running smaller stuff on them? There must be a reason for using smaller amp breakers?

Taking the table saw as an example, I'm guessing the amps is set by the motor, so in theory, that motor will never draw more than (I'm guessing here) 20 amps which is why it'd be ok to have it on a 50 amp circuit?

But back to my question, just to make sure I understand, cause this electrical stuff is always a bit over my head. So there should be no problem, if I'm going to have 1 run put in to make it a 50 amp circuit. I think the one thing I'd need to change is probably the plug on the saw, but that shouldn't be an issue I don't think. And then I should be good with any plug in EV charger I find?

[Jared Sankovich]

ok, I think I can understand what you are saying about the breaker protecting the wire. But if this is the case, why not make all of the runs in the house have very high amp breakers? If there's no fear running smaller stuff on them? There must be a reason for using smaller amp breakers?

Taking the table saw as an example, I'm guessing the amps is set by the motor, so in theory, that motor will never draw more than (I'm guessing here) 20 amps which is why it'd be ok to have it on a 50 amp circuit?

But back to my question, just to make sure I understand, cause this electrical stuff is always a bit over my head. So there should be no problem, if I'm going to have 1 run put in to make it a 50 amp circuit. I think the one thing I'd need to change is probably the plug on the saw, but that shouldn't be an issue I don't think. And then I should be good with any plug in EV charger I find?

$$$ is the reason. Copper is expensive. The braker is sized to the wire. The motor starter/overloads protect the motor.

You could hard wire you table saw to a 100A branch circuit if you wanted.

[Aaron Heck]

ok, cool, I think I got it.

Quick google search tells me 10g wire for 30amp circuit and 6g for 40-50 amps so since this would be a pretty short run, maybe the difference is pretty negligible in cost. Multiple longer runs that would def be a factor, I suppose.

So last question (I hope). If I plug in my WW tools to a new 50amp breaker, does the gauge of the wire from the motor to the plug (to plug in the machine) have to match the gauge of the wire between the breaker and the receptacle? i.e. do I need to upgrade the wiring to my tools if I choose to put in a 50amp breaker?

[Zachary Hoyt]

No. Just like you can plug in a desk lamp to the same plug that you use for a vacuum cleaner. The wire has to be sufficiently large to carry the current from the outlet to the load, and beyond that it doesn't matter.

[roger wiegand]

Well designed EVs (can't speak to GM/Chrysler products) you or the car adjusts the charging rate to the circuit available. So if all you have is a 15 A plug you set the charging to draw 120V/12A and you're good. If you've got a 60A breaker on a wall charger you can charge at up to 48A/240V.

A reasonable bet for future-proofing is to pull #6 copper. You'll need to pull the neutral (4 wires total) if you install a plug, just the 240V hots (plus ground) for a hard wired wall charger due to recent changes in the code made to prevent homeowners from using the ground wire as the neutral when plugging a new electric range in in the garage, I guess.

With a 60A breaker and #6 copper you can charge a present day car at 44 miles of range per hour, plenty for a home charger for any car on the horizon. If you need to power a semi, then all bets are off!

The #6 wire needs to be rated for 90 deg C operation for that maximum draw. NM cable is usually only 60 deg so would need to be derated. THHN in conduit is fine-- and if you put in a big enough conduit you can easily pull bigger wire if needed in the future.

[Prashun Patel]

I am doing exactly what you want to do.
My ev has different plug adapters that go into the charger.

I got the one that supports 20 amps and fits my NEMA plug. It works great. It’s not super fast, but it will do about 50pct a charge on my model 3 overnight. Good enough for me especially since I use about 10pct charge a day.

[Jim Becker]

I see zero issue with you providing a circuit that is up-sized for the EV charging but also used to run a machine during the day as an alternative use.

Now, you might want to consider having said electrician put in a sub-panel instead of just one 240 circuit so you have more flexibility with adding other 240v tools. You may be able to get a tax benefit on at least some of the cost because of the EV incentives, depending on where you live.

[Greg Funk]

$$$ is the reason. Copper is expensive. The braker is sized to the wire. The motor starter/overloads protect the motor.

You could hard wire you table saw to a 100A branch circuit if you wanted.

Not without violating the electric code. The circuit breaker provides short circuit protection for the branch wiring and there are maximum breaker sizes defined in table 430.52 of the NEC. For normal, inverse-time, circuit breakers the max size is 2.5 x FLA of the motor. Max circuit breaker size for a 3HP (FLA 17A) motor is 42.5A which can be bumped up to 45A.

To the OP, if your car is a hybrid, 30A should be plenty for charging. I just use a 20A plug in my garage for my Tesla and it's fine for normal use; a 40 mile commute takes about 3:30 to recharge from a 20A, 240V outlet. If I was frequently driving longer distances I could wire in a larger outlet but haven't had the need so far.

[George Yetka]

May wanna check your breaker to, It may be a 2 pole 20.

[Adam Herman]

Well designed EVs (can't speak to GM/Chrysler products)

The charge adaptor on the wall will tell the car how much it can supply and the car will set its current limit to that number. this is one reason there are communication pins on the charge connecter. all cars will do it, its part of the spec.

anyway.
yes, you should install a nema 14/50 outlet. Its pretty much the standard now for 220 volt stuff. overall the cost will not be that much more than running a 30 amp circuit.

we have installed a 14/50 for our Chevy Volt in 3 houses now and I also use it for welding and the drill press. Volts draw a max of about 15 amps on 220. a device takes as many amps as it needs, and any dead short will blow the breaker even if its a 50 amp breaker and a 15 amp device.


yes, i would put in a nema 14/50

[Adam Herman]

Not without violating the electric code. The circuit breaker provides short circuit protection for the branch wiring and there are maximum breaker sizes defined in table 430.52 of the NEC. For normal, inverse-time, circuit breakers the max size is 2.5 x FLA of the motor. Max circuit breaker size for a 3HP (FLA 17A) motor is 42.5A which can be bumped up to 45A.

To the OP, if your car is a hybrid, 30A should be plenty for charging. I just use a 20A plug in my garage for my Tesla and it's fine for normal use; a 40 mile commute takes about 3:30 to recharge from a 20A, 240V outlet. If I was frequently driving longer distances I could wire in a larger outlet but haven't had the need so far.

just to make up the part left out, hard wired stuff follows a different standard than an outlet.

[Patrick Varley]

Agree with Jim. If they're already going to have to make a new run for the charger, I'd look hard at just having them put in a sub panel, then you can have individual breakers for the charger and saw (or whatever else) off the sub panel.

Going to pay more in materials, but the labor probably isn't much different and the flexibility for the future could be worth it (including an easy way to add a second EV charger).

[George Yetka]

That does make sense and you could always run oversized aluminum with the current prices of copper. Get yourself a 100 amp sub panel for the garage then it will be relatively cheep to run out everything from there. You will also get to reuse all the 10 gauge in the current run