Electrical Question

[Brent Ring]

All,

I have a shop in the 3 part of a 3 car garage. I am looking to add a 3hp Sawstop in June, and need some more power in general - (tired of tripping breakers with heaters, etc.)

We currently have a hot tub that is shut off, emptied, and not in use, and I want to repurpose the hottub circuit. In my main panel in the house, it is has a 50A breaker. I believe it is #6 wire going from that 50A breaker to the disconnect outside, which is a SQUARE HOM2-4L70RB disconnect. It has a 50 AMP main as well with 2 - 20A side breakers installed. Here are my questions.

1. Can I simply move the disconnect from outside into my garage, and use it as the panel in the garage for the new circuits?

2. Can I use the 50A connection to run the 220 circuit that I need - I would like 4 outlets of 220 - and never more that 2 devices on at the same time. ( I can convert my PM 141 to 220, or my Jet 6" Jointer, not sure if it is worth it, though). Or do I need to break the amperage up in to different 220 circuits. I probably need to do that to assure that I dont send too much power to 10 or 12 guage wire, which will negate using the disconnect.

3. The 6 guage wire should be able to handle 70AMPS. Should I change out the main breaker in the basement and then just populate a new panel with the correct mixture of 220 and 110 circuits?

Any and all advice is welcome!
Any advice on making

3.

3.

[Pat Meeuwissen]

Brent, couple of things. First your #6 wire is only rated for 60 amps under the temperature ratings for the most common house wiring Romex.
Also is the wire a 2 conductor or a three wire, if its only 2 wire it will not be usable for the combination of 120 and 240 volt circuits, you need to have a third wire to have a neutral, and also make sure a ground is present. If this is not something you are familiar with leave it to a professional. By asking the question alone it would lead me to believe you could use the help of a Pro. Hope this is some help, Pat

[Lee Schierer]

I agree with Pat. I would also suggest that if the wire has the proper conductors and ground to use the 50 amp breaker and install a sub-panel in your garage with a new box with individual circuit breakers for the new circuits you want. If you get a professional t look at it, you might get a decent price for installing just the box and you can run your own circuits from the new box.

[Brent Ring]

I agree with Pat. I would also suggest that if the wire has the proper conductors and ground to use the 50 amp breaker and install a sub-panel in your garage with a new box with individual circuit breakers for the new circuits you want. If you get a professional t look at it, you might get a decent price for installing just the box and you can run your own circuits from the new box.


Are you talking 3 wires - plus ground? I will need to check - I can't remember from when I installed the hottub circuit.

Good advice on the pro, however, I did most of the work for the hottub, and it was fairly simple. The guidelines I have read said that the #6 could handle 70A without problems but thats ok. Assuming I have the right wire, is 60A enough for 5-6 circuits, including a 4 outlet 220?

[Lee Schierer]

Are you talking 3 wires - plus ground? I will need to check - I can't remember from when I installed the hottub circuit.

Good advice on the pro, however, I did most of the work for the hottub, and it was fairly simple. The guidelines I have read said that the #6 could handle 70A without problems but thats ok. Assuming I have the right wire, is 60A enough for 5-6 circuits, including a 4 outlet 220?

Yes three wire plus a ground. It depends on the amperage of the circuits you are adding. I'm not a professional and I've never slept in a Holiday Inn Express. ;)

[Pat Meeuwissen]

Brent, like Lee said it depends on what the draw is and how many you plan on using at once. If you have your dust collector and tablesaw running together you will be fine but if there are several people working in the shop at once and 4 large draw machines are running you might have a problem.

I am a pro and also didn't stay in a Holiday Inn, but please be careful. Pat

[Jeff Sudmeier]

I have a 60 amp sub in my garage and it is run with 6awg wire. I didn't have an electrician do the work but one did look at it when I was done and approved.

I have 2 20-amp 220 circuits, 1 30amp 220 and 1 20 amp 110. If I ran everything at once I would have a problem, but I have a dust collector on one of the 220 circuits that pulls 13 amps except at start up. The other circuit is used for my jointer, planer and table saw. I never run two of them at the same time. The 30 amp circuit is for a bandsaw, which never runs at the same time as the table saw, etc circuit.

The 110v circuit is dedicated to an air cleaner, which is on all the time.

Good luck! Jeff

[Brent Ring]

I have a 60 amp sub in my garage and it is run with 6awg wire. I didn't have an electrician do the work but one did look at it when I was done and approved.

I have 2 20-amp 220 circuits, 1 30amp 220 and 1 20 amp 110. If I ran everything at once I would have a problem, but I have a dust collector on one of the 220 circuits that pulls 13 amps except at start up. The other circuit is used for my jointer, planer and table saw. I never run two of them at the same time. The 30 amp circuit is for a bandsaw, which never runs at the same time as the table saw, etc circuit.

The 110v circuit is dedicated to an air cleaner, which is on all the time.

Good luck! Jeff


Jeff,

Thanks for the reply. Your arrangement sounds similar to what I want to do - I just dont know if I need a 30A circuit or not. The new table saw I am planning for would consume 1 220 Circuit, and I could probably share that with the jointer and the bandsaw.

Lee, FYI, the wire run was 6/3 wire, so I have what I need to pull 110 circuits off of the new sub-panel. Sounds like I need to pick up an new panel, breakers and some wire!

[Don Jarvie]

You might want to consider a full panel. I ran 6g from my main box to my garage with a 50a breaker in the main box and garage. This way I can kill the power in the main box and work on the garage without having to avoid the main breaker area.

The full panel has 20 slots so I have plently of space with room to grow. I have 2 30a breakers for the TS and heater and 2 20a 220 breakers for the DC and 2 plugs for the BS and Jointer. Everything else is 20a single breakers. Lights are 15a on separate breakers.

All wiring was 12g and 10 for the 30amp lines.

[Bryan Wellman]

If you have a Menards nearby, this is a great price on a Homeline panel with 100 A main installed. You can fuse it at 50 or 60 inside your main panel and use the 100A as a disconnect in the subpanel.

http://menards.inserts2online.com/MenardsMenardsConstructionSale/pdf/20100228-20100314-16.pdf

[Mark Ottenheimer]

If you have a 2 pole 50 Amp breaker in your main panel you will need a 60 Amp or higher rated main-Lug circuit breaker panel. By using the 50 amp breaker with 6/3 Romex you will ensure not heating up the wire and no matter what you hook into the sub panel the 50 amp breaker should trip if it is overdrawn. You do not need a sub panel with a main breaker on it as you are feeding it from the breaker in your main panel. You also need to remove the bonding(green) screw if it is there on your subpanel. You will need a separate groung bar for the incoming and circuit groundings in the sub panel and neutral bar. I am not a licensed Electrician, but I did work for one for years. Your best bet is to do some research on the NEC for sub panel requirements. Just because it works and does not cause a fire does not make it correct.

[Bryan Wellman]

If you have a 2 pole 50 Amp breaker in your main panel you will need a 60 Amp or higher rated main-Lug circuit breaker panel. By using the 50 amp breaker with 6/3 Romex you will ensure not heating up the wire and no matter what you hook into the sub panel the 50 amp breaker should trip if it is overdrawn. You do not need a sub panel with a main breaker on it as you are feeding it from the breaker in your main panel. You also need to remove the bonding(green) screw if it is there on your subpanel. You will need a separate groung bar for the incoming and circuit groundings in the sub panel and neutral bar. I am not a licensed Electrician, but I did work for one for years. Your best bet is to do some research on the NEC for sub panel requirements. Just because it works and does not cause a fire does not make it correct.


If the subpanel is not in the same room or within sight of the main panel you must have a master disconnect to kill it. That is why I suggested the panel that I did. It already had a 100A main built in. You would fuse it at 50A in the main panel and use the 100A as a disconnection means only.

[Chris Padilla]

It sounds like you are doing fine, Brent, but I just wanted to add...to make doubly sure: keep the neutral and ground separate in the sub-panel...they only bond together at the mains.

[Brent Ring]

Well,

I have purchased the panel and built a column in my shop for the power on one side - still need to do the cutins for the outlets. But here is my latest question:

I have 6-3 AWG coming to the sub panel so I can break out both 220 and 110 circuits. However, my electrician apprentice/neighbor told me that I would need to run 10-3 for the 220-30A circuit to the outlets, and 12-3 for the 220-20A circuit outlets. The new Sawstop I am getting does not need 3 conductors. The only reason I am running the 30A circuit is future planning.

All of my research says I only need 10-2 and 12-2 for my 220 circuits. In the panel, I should just need to take the black and white, mark the white red and simply connect connect both to a half of the 220 breaker, and take the ground to the ground bar in the panel. Also, my plan is for two 2 - 220-30A outlets on the circuit, and 3 each for the 2 - 220-20A. Any concerns with that, and with them sharing an outlet box with a 110-20A duplex outlet?

Thanks

[Rob Steffeck]

When I did my shop rewiring I used 10-3 for my 240v outlets even though my current equipment does not use the neutral. I simply capped both ends of the neutrals with a wire nut and folded them neatly out of the way in the outlet boxes and panel. This way, if I ever get a piece of equipment that needs both 240v/120v I don't have run new wire.

[Brent Ring]

When I did my shop rewiring I used 10-3 for my 240v outlets even though my current equipment does not use the neutral. I simply capped both ends of the neutrals with a wire nut and folded them neatly out of the way in the outlet boxes and panel. This way, if I ever get a piece of equipment that needs both 240v/120v I don't have run new wire.



But if you are not using, or planning to use any quipment that needs 110 as well then you would only need 10-2 or 12-2 right?

[Rob Russell]

But if you are not using, or planning to use any quipment that needs 110 as well then you would only need 10-2 or 12-2 right?

That's correct, although you could run 14-2 NM cable for a 240v/15A circuit. Remember that the box fill requirements are such that, if you have 10/2 going into a box to supply a receptacle and then heading out to feed another box/receptacle - you'll need at least an 18 cubic inch box. The same thing with 12/2 would require a 16 cubic inch box.

[Rob Steffeck]

But if you are not using, or planning to use any quipment that needs 110 as well then you would only need 10-2 or 12-2 right?

Thats correct. I don't have any equipment that currently needs 240v/120v, nor do I have any planned purchases that need 240v/120v. But, I hate doing drywall enough to put the extra neutral there just in case. The cost wasn't that big of a deal for me since the runs were short. Additionally, I liked the fact that I have red / black wires running to my 240v machine. Using the neutral as a hot conductor requires marking the end of it (tape / permanent marker). In my over-engineer-everything opinion, it can always come off or wear away over time.