Rewiring garage Subpanel for 220volts, need advice.

The previous owner had installed one 220 volt outlet in the garage. However, I need another two 220 volt outlets. I will be using only two 220 volts outlets at any one time, including lighting. That is; I will be running a 2 HP dust collector (about 10 amps) and a 1-1/2 HP (10 amps) table saw, jointer or planer (both 220volts max 15 amps).

I am thinking of installing a 60 amps subpanel myself for three or four 220 volts 20 amps and a few 110 volts outlets for small hand tools and lighting.

The distance from the main electrical panel to the garage is about 50 feets. To save cost, should I run the wire (what gauge?) from the main panel to the subpanel in the garage and then let a cerfied electictian to hoke it up gfor me test and certify it? I am by no mean an expert in electrical, know a bit but not much.

Thanks, I als appreciate other suggestions.

Reply to
William
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Is the garage attached or detached from the the house?

Based on your apparent knowledge level, the best thing you could do is provide a path for the electrician (either dig the trench to his specs or create a path through the house [drill joists, poke through blocks ]), then let the electrician do it. Odds are a 100 amp panel will be the best buy, the electrician can feed it at 100 amps just about as cheap as a 60 amp.

He's not gonna garantee either your conduit or your wire in the conduit, let him provide both (a nick that goes short is easy to do). You can save by providing the path and managing the inspections. (You call and be there when the trench, rough-in and final are done, the electrician will still correct any faults).

Tim S.

Reply to
TimS

Are you sure your DC is 10a? That is an awful lot for a 1.5hp motor.

How many amps is your existing outlet?. If your DC is only 8 or 9 amps, then you can just add an outlet to the circuit if you have a 20a circuit. You might want to try that first anyhow to avoid the expense of a subpanel; they generally don't pull their full load for very long, if ever.

Reply to
Toller

I'm only estimating it at 10amps. If I remember correctly it should be around 7 amps.

The house have a 200amps main panel. The garage have only one 220volts 20 amps circuit outlet, connect from the main panel and five 110volts outlets from another circuit.

??? what do you mean? I already have an 220/20amps circuit in the garage and think of adding another two 220/20amps circuits.

I am debating whether to pull one 60 or 100 amps subpanel to the garage or pull two 220volts/20 amps circuits to the garage. Which is cheaper and simpler?

I have already bought one coil 250 ft, 12/2 gauge wire, two 20 amps panel switches, I could just keep it or sell in a garage sale later if I decided to install a subpanel, no big deal.

Reply to
William

You now have a single 240v/20a circuit. Is there anything on it at present? If not, and your DC is only 7a, then there is no problem putting the DC and table saw on it. A table saw only draws full current when it is straining. Hopefully that is rare and for very short durations. So, if your TS is 10a, and your DC is 7a, you have a good margin on 20a circuit.

You say the jointer and planer are both 240v also. Presumably they are less than 10a, and you will not be using 2 tools simultaneously, so you are in good shape. All you have to do is install a few more outlets on the 240v circuit. I expect you could actually have two tools running, as long as they were not actually cutting/planing/jointing material at the same time (even then, you can likely get away with a few seconds overlap.)

Your bigger problem might be the 120v. You say you have one circuit. Is there anything on it at the moment, such as lighting? What size is it? If you have lighting on it, and it is only 15a, then you will have problems with a large router; for instance. If it is 20a, or you have a separate circuit for lighting, you might be okay; though a clean 20a would certainly be nice to have.

Running a single circuit, 240v or 120v, is pretty easy. Installing a subpanel is a lot tougher. The components are much more expensive and the cable is much more difficult to run. But I can't see you needing a subpanel; at most a single 20a 120v circuit, if I understand the situation properly.

Reply to
Toller

I believe the NEC only allows for a single circuit out to the outbuilding, if you want more, you need to put in a sub panel in that outbuilding.

60 amp (#6 wire) circuits can be run in 3/4" conduit, which reduces the cost, most bang for the buck so to speak.

To provide a 220 service out to the garage, you'll need 3 wires, two hobs plus neutral (and ground).

Reply to
John Hines

Why would he need a neutral? 240v/20a outlets don't even have neutrals on them.

Reply to
Toller

If your only 120v circuit is connected to both your garage lighting and your bedroom then you have to do something.

Putting in a 60a subpanel will certainly solve all your needs and provide for any conceivable future plans. The hard part is running the cable; it is thick and doesn't want to bend. I don't know if any electrician would be willing to simply make connections on your wiring, but if he is, it couldn't take more than an hour or two. Properly speaking, you probably should get it, and any branch circuits, inspected, but I don't know how many electrians would bother with it.

But I think that is overkill. Your existing 240v circuit will power your DC, TS (when changed to 240v), planer, jointer, and compressor; as long as you don't use more than 2 at a time. If the existing outlet is at the far side of the garage, then cut the cable and run it to a new outlet or four where you want it, and then run a cable from the new outlet to the existing outlet. Unless you have a finished garage, that should be pretty simple. Your observation that the breaker only blew when you were cutting a big piece is because the motor only take a fraction of its maximum unless it is straining. That is why I say you can probably run 3 tool at once if you wanted, as long as they were not all straining at the same time.

240v suffers less from voltage drop than 120v, so a long run isn't as bad as it would be on 120v; plus, two tools aren't likely to surge at the same time, so surge voltage drop is less of a problem. I have my 2hp TS and my 1.5hp DC on a 20a circuit and they purr like kittens.

Leave the lighting on the old 120v circuit. Run a new 20a 120v circuit to a few new outlets for small tools. If you think you need more than that, then run a 120v multiwire circuit. It is not much more work or expense, but gives you twice the power. One thing you will have to think about is GFCI protections. That is required for all 120v outlets in a garage except for outlets used for things that cannot be readily moved such as a table saw, or for outlets that are out of easy reach, such as those for garage door openers.

If you really want a subpanel, then go for it; but unless I am seriously misunderstanding something, it is not necessary.

Reply to
Toller

Thank you for continuing....

My present TS is 1 HP, 110/220volts, 14/7 amps, wired to 110volts. Each time I turn on the TS, all the fluorescent lights blinks. When I rip a thick lumber the breaker trip in the main panel. So I will have to replace the 1HP with 1-1/2hp and rewired it to 220volts.

My present only 220/20 amps circuit in the guage mare not in use, except for the planer/jointer/compressor, in the far side of the garage. I don't want to extend the TS's wire to that 220/20amps outlet.

I believe I could wired the single 220volts 20 amps to two outlets, with only one being use at anyone time. The dust collectors (1 or 1-1/2HP) had to be on a

220/20amps circuit together with lighting(?), as it draw 9 amps. connecting to the TS will be at stretching my luck, and I may have problems again on thicker lumber.

This is probably my main concern, it is connected to my bedroom light and 4 outlets, I will definitely need an electrician to rewired it as a separate circuit. All the garage's fluorescent lights will have to draw from the garage sub-panel, maybe from the dust collectors curcuit?

As you can see I really need a subpanel or at least draw two 20/2 gauge wire from the main panel to the garage. The question how to do it with min. cost and would do all the dirty work and let the electrician connecting it together and sign it off. How would you suggest I come about doing it? Like where to get the City/County code and etc.? How much do you think it cost, like max and min?

The last time I ask a plumber to check and replace the thermostat on my water heater, he charge me $80 for 10 minutes work. After that I do all my own plumber, lighting and replacing the 40 gallons gas water heater all by myself. However, I am a bit afraid when doing electrical, wanna careful especially when I have never install new wiring to main panel.

Thanks, please do advice more....

Reply to
William

The garage is just below the bedrooms, it is not outbuilding.

How about 100 amps subpanel what size wire and conduits?

The sale associate in HD told me 12/2 will be just alright for 220/20 amps wires. Now, I could return them for the size I need.

How much do you think I will have to spend to get an electrician to do the work I posted earlier and plus the work to rewire the bedroom away from the garage lighting circuit?

Thank again....

PS: The questions may be stupid, I'm learning and change as I get more responds.

>
Reply to
William

I'm making an assumption that there is a need for 110v, for lighting if nothing else.

Reply to
John Hines

Then you have a few more options.

Probably, #2 and inch and quarter conduit (or 1.5). Not sure, depends in part on the distance and such.

For 220 only yes, if you want to run a sub-panel, and provide 110 then you need the neutral.

IMHO, a neutral is a good idea, because then you can change back to 110 vac with a simple outlet change.

Depends mostly on how much construction he has to do to run the wires. If everything is nice and open, I'd guess 2-3 hrs, at what ever his rate is.

The only stupid question, is one asked when one already knows the answer.

Reply to
John Hines

I have been wanting to get an electrician to fixed that damn circuit. I guess the previous owner merged the bedroom and garage circuits together. I must be honest, I'm not confident in troubleshooting or fixing that problem.

Getting an electrician to do what i wanted is the problem. I have called at least two electricians and they never show up to give me a quote. That's why I'm here to squeeze as much information before starting. I am getting the Band saw, dust collector and drum sander early spring... getting desperate.

Ah another woodworker! I have a finished garage. I really doubt I can run 2 machines at any one time on the 220/20 amps circuit. I can try next week if weather permit (I still need to finish my WIP snow thrower's carburetor). Even if I could I will still wanna have at least two or more(prefer) 220/20amps circuits in the garage, bearing in mind the dusts collector will be on all the time.

Thanks for telling me of the GFCI and will incorporates into the panel/wiring.

Let say I insist on it, will it be much easier than pulling two or more wires into one or more 3/4" conduits for 50 plus feet in a finished garage? I don't think the cost will be any much more than an additional 60/100amps subpanel. By the way I still have space for two 220/20amps breakers in the 200amps main panel.

Anymore ideas, suggestion or another routes appreciated. Thanks.

Reply to
William

After listening to all of this, I would install two new 12-2 cables from your main panel to the garage. One would be 120V, 20A with a GFCI receptacle as the first one. Put as many receptacles on this as is convenient for all your 120V tools. The other 12-2 would be for another 240V 20A circuit. These can also have multiple receptacles so you can place them where you want them and keep daisy chaining the 12-2 until you're done. You can add more receptacles to your existing 240V 20A circuit if that would make things more convenient. You just have to limit things on each circuit so you're not tripping the breaker (one big and one small item would be ideal).

If you put in a subpanel, you still have to buy everything above, but you'll use somewhat less 12-2 and a fair amount of 6-3 (for a 60A panel). A subpanel will also require the cost of the panel and the 60A double pole that protects the feeder. If you really think you're not going to have enough power, you can install a 3'rd cable along with the other two 12-2's. The three cables should fit in13/16 holes in your studs/joists (6-3 NM would fill the 13/16 hole itself), and you're still within the temperature derating limits with even a 4th cable.

-- Mark Kent, WA

Reply to
Mark or Sue

You don't need a neutral to change back to 120v. One of the hots becomes the grounding conductor. You only need a neutral if you want to run 120v and 240 at the same time; probably not a good idea.

Reply to
Toller

The cheapest and easiest solution is to add a couple of additional 220V outlets to the 220V/20A circuit *that you already have*, and rewire your table saw motor for 220V. You just need a roll of 12/2wg wire and a few switch boxes (or handy boxes and wire clamps) and 220V grounding outlets: - - or - |- o o

The dust collector and jointer probably do not draw anywhere near their rated amperage. The table saw probably does, but only when it is starting up or when you are cutting something thick.

If you have your heart set on a new subpanel, you can buy a 100A main lug panel with 6 spaces for about $15. You will have to install a ground bar kit (just a couple of dollars) and remove the green bonding screw to isolate the neutral from the metal box. Run 6/3wg cable from a 60A 2-pole breaker in your service panel to the lugs in the subpanel. Or if you are cheap, and you never plan to put a welder in your garage, use 10/3wg cable and a 30A 2-pole breaker.

Best regards, Bob

Reply to
zxcvbob

A finished garage will be more difficult, but no difference between rerouting the exising circuit or bringing in a new one. Why do you doubt you can run 2 machines on a single circuit?

Why do you want conduit? Some local codes might require it, or you might have a protection problem, but otherwise 6/3 cable will likely be easier and cheaper. (Aluminum 4/3 is cheaper still, but I am not about to recommend aluminum.) If you have a straight run with no obstacles, then it really doesn't matter what you use. If there are holes to drill (maybe dozens of holes to drill) and bends to make, then a pair of 12/2 will be a heck of a lot easier than the panel requirements. I just ran a 12/2 from one end of my basement to the other. It took about 3 hours. (it would have taken maybe an hour if I had ignored code) 6/3 would have taken all day, and I don't think I could have done conduit; I thought about running a gas pipe along the same route to my laundry room and decided it was impractical.

Reply to
Toller

Vital question. Is the garage attached or detached. If the garage is a separate structure then the sub panel would be the only way to proceed that would comply with the US National Electric Code (NEC). Each building must be supplied by a single branch circuit or feeder. The exceptions to that rule rarely apply to residential properties.

-- Tom H

Reply to
Tom Horne

OK, so far I'm with you. I already have the 12/2wg. What do you mean by 220V grounding?

My jointer is a 2 hp and planer is 3hp. However, I used them once a while when I need to plane a batch of rough saw lumber for a project. The table saw really draw every ounce of juice from the present circuit.

I do have a 180a, AC welder, it's set up to run on 220/20a. I'm confuse on the

6/3wg?

Thanks, getting nearer there.

Reply to
William

Now, I'm narrowing down to either two new 12-2 cables or one 60A subpanel as you describe below. I will have to limit a 220/20A to one big and one small 220volts machine at any one time (still doubtful), while the other 220/20A to just one machine and the 3rd ones for 120V/20A and lighting.

main panel to the

many receptacles on

another 240V 20A circuit.

them and keep daisy

existing 240V 20A circuit

each circuit so you're

use somewhat less 12-2

cost of the panel and

============

going to have enough

cables should fit

and you're still

I'm a bit confuse here, I have a finished garage. The studs are encased with dry wall. I am planning to run two new 12-2's (one 120V/20A and the other 220/20A) from the main panel, taking the same path studs/joists. .. What do you mean by "within the temperature derating limits with even a 4th cable.?"

Thanks for you help

Reply to
William

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