Best options for adding electrical?

[Bruce Walters]

I'm a beginner that is building out a work space in a garage (the space is shared with vehicles). After putting together my HF dust collector, I quickly realized that both available circuits in the garage are 15 amps and the DC pulls 20.

I obviously need to get more power into the garage. I'm far from an expert on electricity and I'm looking at a few different options:
1) Verify that all the wiring is 12 gauge and swap the circuit breakers to 20 amp
2) Run one (or more?) 20 amp circuits into the garage from main panel (or should that be 30 amps?)
3) Have a sub-panel installed in the garage (100 amp?)

The sub-panel would be best, but also the most expensive. I'd plan on having an electrician do any of the above.

Any recommendations or different suggestions?

Additional details in case they are relevant:
I currently have a 240V/50amp line going to the garage for charging an electric car
Current tools:
15amp table saw
15amp miter
15amp benchtop planar
10amp benchtop jointer
20amp HF DC

Because the space also functions as a garage, mobility is important. I don't see the ability to move to "real" jointer/planars in this space. I may eventually upgrade to a 220V table saw, but I'd be able to use the existing car outlet for that.

Thanks in advance for thoughts.

[Frank Pratt]

Put in a subpanel. It won't be much more, & maybe less, that running a bunch of individual circuits. You don't need a 100 panel though, unless you're going to do electric heat. 50A should be plenty.

[Andrew Seemann]

Agree on not needing a full 100A. On my current and last shop, I ran 100A wire to them but only put in a 60A breaker in the main box (100A breakers are typically expensive). I have never popped the 60A breaker, and I have a 3HP table saw, 3HP dust collector, 3HP planer, etc. At my parents, we only had 100A service for the whole house and had 50A going out to the shop from that. We never blew either the 100A fuses or the 50A fuses, and the old man had a welder, compressor, 2HP table saw, etc. 100A is a remarkable amount of power and difficult for one person to use in a shop without electric heat or seriously huge equipment.

[Doug Garson]

I agree at least partially with Frank. Option 1 is highly unlikely and option 2 might be more expensive than 3. I'd have my electrician quote both 50 amp and 100 amp panels, depending on how long the run is, the larger panel and heavier gauge wire might not be much and estimating both would be easy, if the difference is not great gives you lot's of room for future expansion like electric heat, air compressor, lights, fans etc. . I'd also ask the electrician if you can tap off the car charging circuit assuming you can limit shop time to when you aren't charging or vice versa.

[Dave Cav]

50 or 100 amp sub panel off your main, then you can hook up the branch circuits yourself. Depending on where your main panel is located it shouldn't be too expensive to pull one circuit off it and connect to a sub, depending on how the wire has to be routed. Where's your main located?

[Thomas Crawford]

The cheapest option is to turn the 50amp car charger into a subpanel and branch off of that (including the car charging socket). Downside is you couldn't charge the car and do anything else at the same time.

[Bruce Walters]

My main is in the basement on the opposite side of the the house -- I'm estimating it's a 30-40 foot run, but no major obstacles in running new line.

I'm giving serious thought to using the existing car line to feed the sub-panel. It's 6 gauge, so will support 60amp service. I don't have the vehicle in the garage when running any power tools, so dual charging & shop-work isn't an issue.

On the flip side, I've got a 2 year old and another one on the way. It's somewhat attractive to be able to shutoff and lockout power to the shop tools when I'm not in there.

[Andrew Seemann]

I have my electric in the shop set up with a subpanel for the machines controlled by a breaker in the main shop subpanel, so I can drop the power to the machines when I leave the shop or whenever I have little visitors, without killing power to the lights and fridge and heat and AC. I very much like that configuration; it gives a lot of peace of mind. You probably don't need to go to that extent, but having the subpanel set up so you can drop the breakers to the machines/circuits you want to keep little ones away from is nice. You can also have the subpanel put in with a main breaker, and drop out power to the whole thing as well.

[ray grundhoefer]

if the cable going to your car charger only has 3 wires, 2 hots 1 ground it cant be used for 120 volt receptacle. the labor difference between 60 amps or 100 amps will be minimal. If you find the need to upsize later you will end up paying twice

[Lyndon Klassen]

I have my shop currently running on a 30amp breaker. 2hpnsaw. I think a "1.5" hp dust collector. Lots of lights AND an electric construction heater. 30 amps. Can you believe that.

[David L Morse]

Have you tried to run your HFDC on a 15A circuit? It should work.

In it's stock configuration that DC will draw about 12.5A with the inlets wide open. Add some hose and a tool and the current will be close to 10A.

Note that the 16GA power cord has a 15A plug, not 20A.

[Robert Engel]

My advice as a non-electrician:

A subpanel is the best way to go. I'm sure the electrician will suggest this. ;-) If he doesn't, get a second opinion. LOL

40A is adequate unless you will have some 5HP machines, 60A better, 100A overkill.

Put your DC on a dedicated circuit.

Have at least 1 220v circuit for your future cabinet saw & planer ;-) ;-).

Run circuits in exposed wall mounted conduit. You or your mate may object, but you can always paint it. But is gives you flexibility to add, change circuits. The electrician will like you, too.

If I had to do over, I split the outlets and make the top and bottom different circuits. You do this by running 2 hots and splitting off to top and bottom of the outlet. Or you can put in a 2 gang outlet box and alternate outlets. Either way, then you can plug a shop vac into the same outlet as, say, a miter saw not worry about overload.

Upgrade your lighting if you haven't already done that.

Lastly, hire an electrician............oh you already did that.

[Rod Sheridan]

As has been indicated, your car charger probably doesn't have a neutral so you cannot use it for a sub panel feed.

A 60 ampere feed would be more than adequate, my shop has a 30 ampere feeder for 4HP machines and a 1.5 HP cyclone. Lighting is not on the shop feeder, I have a 15A feed for that from the main panel.

As all my shop receptacles are on a multi-wire branch circuit, I have a single locking disconnect switch that feeds all the machines except the cyclone which is on a separate circuit.

Of course now that my kids are in their thirties the switch hasn't been opened in more than a decade.....Rod.

[Bruce Walters]

Have you tried to run your HFDC on a 15A circuit? It should work.

In it's stock configuration that DC will draw about 12.5A with the inlets wide open. Add some hose and a tool and the current will be close to 10A.



I tried running it off both 15A circuits I currently have available in the garage. Both tripped within 2-3 seconds. Very little else (if anything) was currently drawing current at the time.

[Jim Becker]

Those two garage circuits may have other things on them if it's a typical home build. I agree with the sub-panel route as the best possible solution. One run back to the main panel and then flexibility for your woodworking needs away from already installed house circuits which can be "wonky", depending on how they were designed. A sub-panel and then simple surface mount with PVC conduit makes for a very easy install that's also easy to adapt to changes.

[Tim Bridge]

Is the garage attached to the house?
It makes a difference code wise as to what you can do.

As a master electrician, I would install a panel in the garage and transfer whatever garage circuits into the new panel.

FYI, it is a code violation to run multiple circuits to a detached garage.

[Wade Lippman]

1) A couple years ago HF DCs were 120v 13a. Probably still are.

2) I had a 3hp cyclone, 3hp planer, 3hp TS, a 3hp jointer, and assorted 120v tools on a 30a subpanel. Obviously I didn't use them all at the same time.

[Brian W Evans]

I put a subpanel in my garage last year and am very pleased with it. I had an electrician put in the panel, but adding circuits for outlets, lights, heater, etc. is easy so I do it myself. I use EMT (metal conduit) to get the wiring from the panel to its end point. This is also pretty easy once you watch a few videos about conduit bending. Doing it this way means I can add a circuit in no time using off-the-shelf parts - very convenient.

For my 120v outlets, I always use 20 amp breakers. The price difference in wire, breakers, outlets, etc. is negligible and you are more likely to be able to run multiple tools off of one circuit.

You never know what you're going to end up running in the garage - maybe you'll end up welding, or running a couple of fans, some lights, and an HVLP sprayer for a paint booth or, if you're really lucky, you'll get some monster machine that requires its own 40 amp circuit plus dust collection.

[Karl Loeblein]

Is the garage attached to the house?
It makes a difference code wise as to what you can do.

As a master electrician, I would install a panel in the garage and transfer whatever garage circuits into the new panel.

FYI, it is a code violation to run multiple circuits to a detached garage.

Tim, Is it a code violation if each circuit gets run to separate sub-panels (assuming each circuit comes from it's own 220V breaker on the main panel)? If so then any idea why?

[Steve Eure]

I'll weigh in on this one since I just added a sub panel to my shop. After much time at the computer planning and pricing, I went with a 100 amp panel simply because it offered more spaces for breakers. I also got a deal on the panel with several breakers in a package deal and it ended up only being around
$20 dollars more over the 50 amp.
I also have a space heater in my shop that requires 30 amp 220 and if I'm running my TS and DC at the same time it pulls quit a load.
Personally, if you are going to add more tools later, why scrimp to save a few bucks.

[Bruce Walters]

Is the garage attached to the house?
It makes a difference code wise as to what you can do.

As a master electrician, I would install a panel in the garage and transfer whatever garage circuits into the new panel.

FYI, it is a code violation to run multiple circuits to a detached garage.

Yes, garage is attached to house.

At this point, I think I'm going to run 100A to the new sub-panel in the garage with a lockout switch. After sharing the safety benefits of the subpanel with the boss (wife), she's on-board with spending the money.

I'll hire out the panel & switch install, but feel comfortable running my own circuits off the panel.

I really appreciate everyone's insights.

[Frank Pratt]

Just a note about the panel market around here. The only resi panels that are rated below 125A are little 2 - 8 circuits. The price for 125A panels probably only varies about $30 from a little 16 circuit to a big 40 circuit, so if you have the few extra inches, go for the bigger one. And there's the marketing quirk that has the price of a panel with a 100A main breaker significantly less that the same size panel with no main. It is nice having the main breaker there to shut everything down if desired.

[sean meltvedt]

398702Bruce, if you follow Roberts good idea about splitting the plugs, be sure to bring another identifiable neutral wire as well. Or if doing a multiwire branch, be sure to glance at 210.4 in the NEC. It is a small section that is surprisingly easy to read:)
cheers
Sean

[Bill Dufour]

Sean nice to see the electrician installed all those sideways outlets correctly. I see them backwards from time to time.
Bill D.

[sean meltvedt]

Bill - perhaps sometime I’ll learn how to take and post photos :)

[Roger Feeley]

I've gone the sub-panel route twice. I suggest that you put in a big indoor cutoff switch (https://www.homedepot.com/p/GE-30-Amp-240-Volt-Non-Fuse-Indoor-Safety-Switch-TGN3321CP/100674081?cm_mmc=Shopping%7CG%7CVF%7CD27E%7C27-8_CIRCUIT_PROTECT._DEVICES%7CNA%7CPLA%7c7170000003 3149223%7c58700003867184469%7c92700031085874873&gclid=EAIaIQobChMI19f1-paq3wIVAUSGCh1CQwxWEAQYBCABEgK98fD_BwE&gclsrc=aw.ds) between the main panel and your sub-panel for two reasons. I suggest at least 70 amps which is what I have and seems to be plenty.

1. That switch is your line of demarcation between the professional and the amateur. Have the electrician put in the switch and you can wire everything 'downstream'.
2. You have the peace of mind that once you throw that switch, your entire sub-panel is dead and you can do anything you want.
3. That fuse is your 'get out of jail free' card. If you do short something out, the fuse protects your house.
4. Safety. Mount the switch low and teach any children that, "If Daddy gets in trouble, pull the big red lever".

I have done this twice and the pros like it. I leave all the house wiring to them and I own the sub-panel and any wires coming out.

Additionally, to help separate the amateur from the pro. No wiring in my shop travels behind walls. It's either surface mounted Romex or in conduit. That makes it all very easy to tear out if need be. Again, I have the peace of mind in being able to say that all my wiring is clearly visible.

Leave the existing circuits and lights in place for when you work on your electrical. My current shop is in my basement in a house we had built. I had the builder put in a few outlets and lights so I would have something when I shut my electrical down.

[Roger Feeley]

Regarding the amperage. I have a 100A sub-panel but a 70A cutoff fuse. I've never had a problem. But I work on my own with one machine at a time + the dust collector. My lights are all LED and draw about 7 amps. DC is 1.5HP. Table saw is 3HP.

So unless you have a welder in your future, 70 is gobs.

Consider going to Habitat ReStore for the Sub-Panel. When I moved, I gave mine away to ReStore. You might have to haunt the place a few times. Or maybe there are electricians around that might have something.

[Frank Pratt]

I've gone the sub-panel route twice. I suggest that you put in a big indoor cutoff switch (https://www.homedepot.com/p/GE-30-Amp-240-Volt-Non-Fuse-Indoor-Safety-Switch-TGN3321CP/100674081?cm_mmc=Shopping%7CG%7CVF%7CD27E%7C27-8_CIRCUIT_PROTECT._DEVICES%7CNA%7CPLA%7c7170000003 3149223%7c58700003867184469%7c92700031085874873&gclid=EAIaIQobChMI19f1-paq3wIVAUSGCh1CQwxWEAQYBCABEgK98fD_BwE&gclsrc=aw.ds) between the main panel and your sub-panel

That really is just a waste of time, money & space. The sub-panel will be fed by a circuit breaker in the main panel which will serve as a shutoff & overcurrent protection. If you want a master shut off in your shop, just use a panel that has a main breaker in it. Around here, they're cheaper than the panels without one.

As far as isolating the DIY wiring from the rest of the house, it's totally unnecessary unless the DIY stuff is done incorrectly. If you are not absolutely sure your doing it right, then find someone who does. And get a permit & have it inspected.

I agree that 70A is lots for a straight up hobby wood shop.

[Tim M Tuttle]

I was in a similar situation to you last year and I decided to put a 100 amp sub panel in my garage. An electrical outfit here in town offers engineering services where they walk you through everything you need to buy and install and also pull the permit. I did all the work myself and the electrician was around to answer any questions I had and also came by a couple times to check on my work. The physical part of electrical work is pretty easy. It's all the codes and dos and donts that get tricky. I probably saved myself $1500 doing it this way and learned a ton. I really enjoy doing electrical work so this was a really fun project.

[Bill Dufour]

C-list and Ebay can be a source for a used panel loaded with breakers and wire. Depending on inspectors allowing used or not. For my shop I bought a used 100 amp panel with about 12 breakers for less then the cost of a empty panel from the box store. If all your panels are the same make you can swap breakers around for testing and as needs change.
Bil lD.

[Roger Feeley]

Frank,

I did the cutoff for a number of reasons. One of the biggest was to make an emergency switch accessible to my 8 year old daughter (and now to my grandsons). I put the switch beneath the sub-panel and it's easy to teach the young one to go pull the red lever.

I've had very positive feedback from electricians about the cutoff. It wouldn't surprise me at all to find out that I'm violating some code someplace. I'm not the least bit concerned about the safety of my wiring. But I still like the peace of mind that total isolation gives when I'm messing around in the sub-panel.

[Frank Pratt]

Hey Roger, I understand your reasoning there. It never hurts to go the extra mile if you feel it's worth it.

[Roger Feeley]

Frank,

I freely admit that what I have is a bit of overkill. I'm retired and this will probably be my last shop so I wanted to do it up right and I could afford it. We old people want things tidy. But I've had this feature before. This is my third basement shop. Two shops ago, I had a neighborhood friend who set up the same thing for me. He was chief electrician at a power plant but needed some extra money (4 kids in college at once!). He suggested the cutoff and got me a deal. He was the one that wanted that dividing line between licensed electrician and weekend warrior. I've had other electricians over and they have always made very positive comments.

When I moved to shop #2, I had my friend remove the cutoff and sub-panel and re-install it at the new house. When I moved to shop #3, I had another electrician friend remove it all and I brought it with me. I wanted more amperage than it could handle so I gave it away and put in a bigger rig.

I only use the cutoff when I'm messing around in the sub-panel. I should be fine just killing the breaker in the main panel but...belt and suspenders. The big thing is the emergency switch.
When I work downstream of the sub-panel, I kill breakers.