LumberJocks

220V Power in the Shop

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by GrizzlyBagWorks posted 02-16-2018 08:52 PM 1047 views 0 times favorited 25 replies Add to Favorites Watch
View GrizzlyBagWorks's profile

GrizzlyBagWorks

91 posts in 1617 days


02-16-2018 08:52 PM

Thanks for the feedback guys. I decided to remove the original video from the thread for safety concerns. I did more research and spoke to a few people and have corrected my setup. I wouldn’t want anyone to emulate what I did.

I’ll just say that I modified my system to add in a sub panel with a pair of 15 amp breakers wired with 12g cord. I kept my contactor switch and wired it so that the 220v contactor is fed by the 15amp 220v breaker.


25 replies so far

View woodworm1962's profile

woodworm1962

145 posts in 126 days


#1 posted 02-16-2018 09:01 PM

WHen i wired my shop I thought what the heck I will never trip a breaker casue I will never have everything on at the same time. Like the drill press and table saw and dust collection…

Yes you will.

I did run some dedicated circuits to like my table saw, and another high amp tool BUT all of the outlets are on one circuit and I have to use electrical heat and small fans to blow the hot air around then if I am running my band-saw and the compressor kicks in LIGHTS OUT!

If i do it over each large machine will have its own circuit and the outlets will be a circuit one for each wall. I even have a separate line run for a small AC unit when the weather gets hot

I am getting ready to run a separate one for my compressor!

GESS its always something

-- No one likes the truth...

View ArtMann's profile

ArtMann

950 posts in 842 days


#2 posted 02-16-2018 09:50 PM

You are in violation of the National Electrical Code in many ways and you have more than one situation that can be fire hazard. The worst I can see is you have a 12 and 16 AWG wire being protected by a 30A breaker. If a load shorts, the wire could get hot enough to start a fire. You also have several loads fed by a single 240VAC 30A circuit at one time. It doesn’t matter if you only use them one at a time. It is a code violation. You will certainly have to remove all that stuff if you sell the house and it requires an inspection.

View Rick's profile

Rick

9728 posts in 3059 days


#3 posted 02-16-2018 10:02 PM



You are in violation of the National Electrical Code in many ways and you have more than one situation that can be fire hazard. The worst I can see is you have a 12 and 16 AWG wire being protected by a 30A breaker. If a load shorts, the wire could get hot enough to start a fire. You also have several loads fed by a single 240VAC 30A circuit at one time. It doesn t matter if you only use them one at a time. It is a code violation. You will certainly have to remove all that stuff if you sell the house and it requires an inspection.

- ArtMann

Exactly Art!

1-A Licensed Electrician should do the work. 2- An Inspection by the City to APPROVE the Installation 3- INSURANCE! If a fire does break out and it wasn’t an approved Installation, they will NOT pay out Anything! That’s BIG $$$$$’s!

Rick

-- LIFE is what happens when you're planning on doing Other Things!

View KeithMathewson's profile

KeithMathewson

4 posts in 1563 days


#4 posted 02-16-2018 10:07 PM

I would recommend removing what you have and installing a small sub panel. A breaker protects the wire, the breaker amp load is related to wire size, two pole breakers are for 220v loads. With the new panel you can install breakers for the various loads and avoid pulling a load off of one leg of a 220v circuit. You can install as many circuits as you wish on the new panel, if the combined load exceeds 30 amps the breaker off the main panel will trip protecting the feed to the sub panel

View Charlie H.'s profile

Charlie H.

222 posts in 676 days


#5 posted 02-16-2018 10:09 PM

Electrical problems burn the house down.
Gas problems blow the house up and then burn the rest.

-- Regards, Charlie in Rowlett, TX --------I talk to myself, because sometimes I need expert advice.---------

View GrizzlyBagWorks's profile

GrizzlyBagWorks

91 posts in 1617 days


#6 posted 02-16-2018 10:37 PM

Thanks guys.

I’m a little confused though. How is this setup any different than say a 110v 20amp circuit in my garage with multiple outlets? Let’s say I’m in my garage running a 14g extension cord with 3-outlets on the end. One is hooked up to a 15 amp table saw and the other to a 7 amp drill press. How is that different than what I’m doing here?

The 12g cord is running to a tool requiring 10amps. My understanding is the cord can handle 20 amps

The 16g cord is running to a tool requiring 7.5amps. My understanding is the cord can handle 13 amps.

So in each case the wiring is 2x the amperage rating of the tool.

I set it up this way to take the dust collector off my 20amp 110 breaker in the garage. I was able to run my 13amp table saw+ dust collector (15amps at 110v) without blowing the 20amp breaker. Isn’t that more of a risk?

Thank you for all your comments. I’ll add that this is a temporary solution, is never plugged in while I’m not in the shop.

View KeithMathewson's profile

KeithMathewson

4 posts in 1563 days


#7 posted 02-16-2018 11:18 PM



Thanks guys.

I m a little confused though. How is this setup any different than say a 110v 20amp circuit in my garage with multiple outlets? Let s say I m in my garage running a 14g extension cord with 3-outlets on the end. One is hooked up to a 15 amp table saw and the other to a 7 amp drill press. How is that different than what I m doing here?

It is very similar to what you describe, except you are pulling off of one leg of a two pole circuit. A 14 gauge extension is undersized for a 20 amp breaker. While what you describe will work, let’s not consider voltage drop right now, you will find that the extension cord gets warm because the wire size is too small. The same thing applies to your setup. If additional load is placed on the smaller gauge line for any reason the line can overheat and burn possibly resulting in a fire.

View GrizzlyBagWorks's profile

GrizzlyBagWorks

91 posts in 1617 days


#8 posted 02-17-2018 12:03 AM

So are you guys saying that the only extension cord that should ever should be used on 20 amp circuit is one that is matched to a 20 amp breaker? So a 12g extension? I thought the only critical part was matching the gauge to the amperage draw of the tool itself, not the amperage rating of the breaker.

Thank you!!

I have like 50’ of 10/3 cord. What if I were to change the 12g & 16g to 10 gauge wiring?

I’m not looking to pass an inspection, just to be as safe as possible. I’m not worried about this setup catching my house on fire while I’m asleep. It’s only plugged in while I woodwork and the circuit is broken anyway by the contactor switch.

View KeithMathewson's profile

KeithMathewson

4 posts in 1563 days


#9 posted 02-17-2018 12:22 AM

I’m not an electrician. What I know comes from working next to an electrical contractor for 15 years and listening to what they told me when they repaired or installed equipment for me. Upgrading the wire size will cover the circuit protection assuming your contractor is rated for it. What you are not supposed to do is pull a 110v circuit off one leg of a 240v line. I wish I could tell you why but I just remember early on when I had that in my shop they ran a new circuit to replace it.

View GrizzlyBagWorks's profile

GrizzlyBagWorks

91 posts in 1617 days


#10 posted 02-17-2018 12:27 AM

Thanks Keith. The contactor is rated to the breaker, 30amps. The cable from the wall to the contactor is 10g. I can replace everything with 10g if necessary.

Regarding the 120v and 240v. You can’t pull a 120v leg off a 3 wire 240v because there is no neutral, you have two hots and a ground. Some guys will ignore that and pull a a hot leg off and then use the ground as a neutral but you really shouldn’t.

View WhyMe's profile

WhyMe

1025 posts in 1587 days


#11 posted 02-17-2018 12:30 AM

NEC only covers the building circuit from panel to the dryer outlet, so you are not in violation of the NEC. NEC doesn’t cover creative stuff that is plugged in. That being said, the bad part is using the 240V outlet to supply 120V because you are using the ground as a neutral conductor which is not safe and can present a shock hazard from the ground.

View jonah's profile

jonah

1727 posts in 3324 days


#12 posted 02-17-2018 01:49 AM

Definitely not safe. You could easily pull 30amps down 14-gauge wire with your setup, which poses a very real risk of fire. You’re not going to blow anything up, but when it comes down to it, is there a real difference between blowing your house up and burning it down?

I usually tamp down the “INSURANCE WON’T PAY FOR IT” fear mongering, but in this kind of a case, an insurance inspector could very easily pinpoint your substandard electrical work as the cause of the fire. It’s different than a slight mistake in sizing an outlet or something like that. This is incredibly obvious as a source of problems – not to mention it just isn’t safe.

Replace all the wiring connected to that 30A circuit with 10AWG. Do not split 240V off for 120V receptacles. Run a single circuit to each 240V receptacle, since that is NEC. You used to be able to run more than one 240V receptacle off a single circuit if the circuit was < 20A, but you can’t do that anymore I don’t think.

View WhyMe's profile

WhyMe

1025 posts in 1587 days


#13 posted 02-17-2018 02:09 AM

NEC is silent on multiple outlets on a circuit based on amperage. The international residential building code does limit multiple outlets on a circuit to 20A be it 120V or 240V.

View GrizzlyBagWorks's profile

GrizzlyBagWorks

91 posts in 1617 days


#14 posted 02-17-2018 02:25 AM

Just to clarify, I’m not pulling 110V off anything. I’m using a 30amp 240v contactor switch that is actuated by a 110V remote switch. The 110v remote switch is powered by a 110v outlet. The contactor physically breaks the connection when the 110V remote outlet is de-energized. It’s impossible for power to be going to the dust collector when the remote is off.

I realize my house isn’t going to blow up, the comment was made in jest.

I’m not worry about passing code. This is a temporary setup. It’s never going to draw more than 20 amps. I just want it to be safe.

I really appreciate everyone’s input but I feel like there’s more misinformation regarding this stuff than there is with dust collection. I don’t know what’s legitimate and what’s parroted mis-information. I’m not talking about this thread or it’s comments in particular, rather that’s the general feeling I get after reading through multiple threads.

I think I have a better way to do this than what I original posted. 10a dryer plug straight to the 220V 30a contactor switch. Then a 10a wire out of the contactor to the 6-50R plug receptacle. From there I’ll have a 15’ 10g extension with one end plugging into the 6-50R receptacle and the other end will be an electrical box with two outlets. One for the dust collector, one for the jointer. The way the contactor breaks the connection to both tools whenever I turn the dust collector off and everything will have a 10g cable except for the cords coming out of the machines themselves (6’ of 12g from the jointer (10 amps running) and 6’ of 14g on the dust collector (7.5amps running))

View 49er's profile

49er

171 posts in 1630 days


#15 posted 02-17-2018 02:45 AM

My gosh I sure get tired of all the license for this and license for that. I agree a person should know what he is doing and be sure it is done right but I sure get sick of only this guy can do this work. For example I have never been a licensed electrician but I was an aviation electrician and I was an elevator mechanic and worked as electrician and instrumentation tech at Rohm and Haas chemical company. I can even put in my own hot water heater and I am not a licensed plumper. I do my own AC work auto and home that is a big No No. I installed a geothermal heat pump without a license and it still works after 10 years. Grizzly needs some assistance and maybe someone to check his work but come on enough with the licensed crap. Maybe someone should be licensed before they turn on a table saw or a router, yea you should have to pass a test, that would probably stop some accidents. How about a license before you can shoot a gun that might help. I’ll stop now, I feel better.

-- Correlation is not causation but I did loose my Doctor !!!

showing 1 through 15 of 25 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com