Anyone install an subpanel in their workshop?

[Tim Dorcas]

I have 1 15 amp circuit that powers the entire garage. Yes. I have tripped the circuit. Too many times in fact. It will cost me $800 to $1200 to get someone to run a line for the subpanel and a couple of circuits. OR I could do it myself. It looks like a fairly straight shot to the garage without digging up anything or destroying multiple walls.

Is it doable? Is it reasonable to think a "Handy" man can do it?

Tim

[Don Baer]

I have 1 15 amp circuit that powers the entire garage. Yes. I have tripped the circuit. Too many times in fact. It will cost me $800 to $1200 to get someone to run a line for the subpanel and a couple of circuits. OR I could do it myself. It looks like a fairly straight shot to the garage without digging up anything or destroying multiple walls.

Is it doable? Is it reasonable to think a "Handy" man can do it?

Tim

yes you can do it. Not that hard as long as you plan it our or maybe all you need to do is install a few more circuits from you main panel. In order to advise you we need more information. What panel space is avaible in your existing main. What laods/tools are you planning to connect? You might be fine with running a couple of 220V runs and a couple of 11V circuit or you might neeeed a sub panel or you might need to upgrade your service. To quote an older movie we need "Input"

[Alex Shanku]

I was in the same boat. I pulled the existing wire, ran 4 pieces of 8ga to a subpanel, and then wired a 220v outlet and a bunch of 110v

[Cecil Arnold]

Another thing you might consider, if you are not comfortable doing wiring. You might rough in all the circuits, stick the sub panel in, and do everything you feel okay with, then find an electrician who might be interested in making a couple of extra $$ to cut it all in for you.

[Tim Dorcas]

To answer some earlier questions....

I have a 125 Amp panel with 6 slots available.

The biggest thing I have at the moment is my table saw. While it's running at 110 now, I want to switch to 220. I need to be able to run my dust control unit at the same time. Then I have the normal assortment of power tools.

The run to the garage is about 25 feet.

I don't necessarily think I absolutely need a subpanel. Just trying to think ahead.

Any and all advice is welcome.

Tim

[Don Baer]

OK time,
Thinking ahead. You are a one mane shop so you will only be running one machine at a time (Except for the DC) right? Not knowing the size of the DC I'd look at two alternative, keeping in mind with a 125 AMP service you still need to supply the house.
Option one
2 - 220 Volt circuits (20 amp)for DC and any other bog loads + 2 110 Volts circuits for recepticles (15 amps each)
Or Option two
1 new 60 amp sub panel and repeat step one for your loads. I opt for option 1

There are some benefits for option 1 but since your gonna be maxed out the only benefit I can see is more space in the main for additonal circuit should you plan on adding them later.

[Andy Hoyt]

Whatever you do - include a subpanel in the shop.

Makes life really easy down the road when you want to change something.

[Brad Olson]

I did it myself, pretty easy, just make sure you read up and get a permit.

Note that copper wire prices are wicked expensive. I don't know if prices will come down or not, but you feeder wire will probably set you back a lot of $$ depending on how long the run is. Probably $3 per foot if you use copper.

["Gary Brewer"]

Hello Tim: Fine Homebuilding No. 154 ( April, 2003 ) has an excellent article on wiring subpanels. The article starts on page 96. Take a look at it. It will help prevent mistakes.
Gary

[Norman Hitt]

IMHO any space used for a shop should have it's OWN subpanel, then you can wire anything in there anywhere anytime the need arises and with very little hassle. Another advantage is that you can leave your current ceiling light on it's present circuit with it's breaker in the house panel, and then wire any other lights off the subpanel, then should for some reason you trip the subpanel breaker with a tool running, the one ceiling light that is on the house panel will still be on and not leave you in the dark with a tool/blade running. It will also leave more spaces free in the house panel. The last advantage is that you only have to pull the three subpanel cables + bare ground wire from the house panel to the sub panel instead of all those wires for the different circuits from the house panel to the shop. It just seems like a much better setup IMHO.

Note: The bare ground wire between the house panel and the sub panel may or may not be required where you are, but the local folks here require it to eliminate something I think they call a looped ground, (or something like that).

[Alan DuBoff]

IMHO any space used for a shop should have it's OWN subpanel, then you can wire anything in there anywhere anytime the need arises and with very little hassle.

I don't get this. Tim stated that he has 6 slots available. He didn't state how much amps total on the breakers in the panel already. With 6 slots, and especially if the panel is in the garage, what is the advantage of running a seperate panel, it will go to the same 125A panel he has. Since he has 6 slots, he can do quite a bit in that panel.

I would think better would be to install a new breaker, run wire to spec, and add a disconnect with slo-blo fuses so that the circuit is protected. That's what I did in my shop, and I only have 1 slot left, which actually has a breaker and outlet on it, I just don't use it that I know of.

I do have another panel running off of it, for my office in my backyard, and it has 3 breakers in it. I can't do anything much more, other than the 1 circuit that isn't used (was for the washer/dryer, and it is 240v), so that will turn into a new circuit in the garage. I could remove that breaker and add to the other panel, but my 125A is pretty much max'd out per amount of amps on it. I'll need to pull another 125A if I ever want to have more power.

Best advice is to get someone that knows what they're doing as far as electrical. If that is a friend that you trust, that works, or if that is a contractor, that works also. Just make sure it's wired correctly.

If 6 slots won't take care of his shop, well, sure get another panel...but I'm not sure I see the advantage other than spending more $$$s, when there's 6 slots available. Tim must have more amps he can use if there's 6 slots available. Unless he has some mammoth panel to begin with.

[Rob Russell]

Alan,

The advantage to a subpanel is that you have the ability to add circuits in that remote location without taking up slots in the main panel or running conductors all the way back to the main panel.

FYI, the number of open slots in a panelboard has nothing to do with the total load that panelboard is servicing. Likewise, you don't just add up the value of all the breakers or fuses in a panelboard and call that your load either, because all those circuits are not likely to be running at their respective limits.

Norman,

The reason that 240v subpanels have 4 conductors (2 hots, neutral, grounding) is because of the NEC bonding rules. There is a whole section of the NEC dedicated to Grounding - Article 250. One rule is that the neutrals and equipment grounding conductors are connected at one and only one point, and that point is the "service equipment". That's also where the grounding electrode system is tied in (connections to water pipes, ground rods and rebar in foundations).

For most of us, the service equipment is our main panel. After the service equipment, the neutral and equipment grounding conductors are separate and the neutral is "isolated", meaning it is not connected to the metal case of panel and is completely insulated from the panel. The neutral and grounding conductors have separate buss bars they connect to, where in the service equipment all the conductors can land on the same buss bars. It is possible to have your main panel wired as a subpanel. If your meter and service disconnect is a ways away from your main panel, it's quite likely that your bonding point is at the disconnect and your main breaker panel is run as a subpanel with separate and isolated neutral and equipment grounding conductors.

Rob

[Russ Filtz]

One other tip, use at least 1" conduit for the subpanel run, no matter what the code or anyone says! I tried 3/4" on mine, but due to some bends between pull points it wouldn't go through (even with plenty of lube). Pulled so hard I worried about damage to the wires.

Had to scrap everything and start over with new copper and 1"! Went much easier that time. The 4-wires is correct. You have to break off a tab inside the subpanel connecting the ground & neutral bus bars.

[Rob Russell]

One other tip, use at least 1" conduit for the subpanel run, no matter what the code or anyone says! I tried 3/4" on mine, but due to some bends between pull points it wouldn't go through (even with plenty of lube). Pulled so hard I worried about damage to the wires.

Had to scrap everything and start over with new copper and 1"! Went much easier that time. The 4-wires is correct. You have to break off a tab inside the subpanel connecting the ground & neutral bus bars.

Russ,

What size subpanel did you run and what did you use for conduit?

Rob

[Wes Billups]

Alan,

The reason that 240v subpanels have 4 conductors (2 hots, neutral, grounding) is because of the NEC bonding rules. There is a whole section of the NEC dedicated to Grounding - Article 250. One rule is that the neutrals and equipment grounding conductors are connected at one and only one point, and that point is the "service equipment". That's also where the grounding electrode system is tied in (connections to water pipes, ground rods and rebar in foundations).

For most of us, the service equipment is our main panel. After the service equipment, the neutral and equipment grounding conductors are separate and the neutral is "isolated", meaning it is not connected to the metal case of panel and is completely insulated from the panel. The neutral and grounding conductors have separate buss bars they connect to, where in the service equipment all the conductors can land on the same buss bars. It is possible to have your main panel wired as a subpanel. If your meter and service disconnect is a ways away from your main panel, it's quite likely that your bonding point is at the disconnect and your main breaker panel is run as a subpanel with separate and isolated neutral and equipment grounding conductors.

Rob

Rob, I am a couple days away from installing a sub panel in my basement shop. I purchased a 100 amp 12 slot panel from HD. If I understand you correctly I should pull a four conductor wire back to my main panel and terminate the neutral and ground on the appropriate buss bars. I was planning on running another bare copper to the water line just as the main panel but it sounds like that is not required.

Two questions;
I was thinking about only running a 60 amp breaker to the sub panel but am wondering if I should just go with the 100 amp while I'm at it?
Does the supply line to the sub panel need to be in conduit if the entire run will be covered with drywall?

I have 200 amp service to the house so I think either size is acceptable.

Thanks,
Wes billups