Hello everyone.  I just signed up and would appreciate any help, advise, and suggestions.

I have never rewired a room before.  I have done simple things like dimmer switches, hang ceiling fans, and relocate outlets.

The scenario:  My three car garage is open studs and detached from my house.  I am converting the farthest bay into my workshop.  The are no reachable plug outlets, and very poor lighting.  The garage has two outlets on the ceiling for the garage door openers.  There is one outlet by the door that leads to the house (on the opposite side of my workshop), and two standard light/light bulbs on the ceiling.

The previous homeowner had an outdoor hot tub on the slab/back porch.  They ran underground wires (it looks professional, but I don't know) from the breaker to the slab.  These are TWO dedicated 50 amp breakers.  I'm pretty sure that is more power than I will ever need.

I want to add two florescent tube hanging lights above my workbenches (I built two 6' workbenches that run the length of the last bay).  I am considering using a 3 way switch for the lights so I don't know if I can run them off my current wiring.  I want to add at least 4 plug outlets.  I will also have one additional non GFCI outlet dedicated to a fridge.  I have a portable Ryobi table saw.  I use cordless tools, but I have a corded drill and miter saw.  I plan on buying a router, compressor, etc.....someday.  I will probably use a mix of 15 and 20 amp outlets.  I only want to do this once, so more is better.  I will mainly be doing wood work/carpentry.

My thought is to tap into the wires from the hot tub and extend the underground conduit to the garage, about another 15' of cable, and connect them to a sub panel that I will run all my new wiring from.  The wires from the breaker to the tub is probably 75'.  My estimates are conservative, but I will measure them this weekend to make sure.

I thought I would find a website that will show me the correct way to wire the garage and then probably have an electrician look at everything and do to the final hook-up.  From the little research I have started, it seems i cannot run wire through the studs on an open wall.  Therefore my wiring requires a lot more wire.

I'm sure I have left plenty of details out.

Please ask as many questions as you would like.

Thank you all for your assistance.

Jonathan

first thing is to get a good electrican to check out what you now have there, then he should be able to tell you what you can and can't do this will cost you a little bit of money but it may just save your life, there is NO way to tell if what is there is safe and up to code, take the time and find out

How far is the garage from the house? Have you considered putting in an entirely seperate service for the garage / workshop? If you plan on adding a lot of stand alone equipment, compressor, tablesaw, jointer, planer, drillpress, dust collection, heat and / or AC etc in the future, that would be my suggestion. My shop is about 40 ft from the house and that's what I did, although I had underground cable ran for fishponds within a few feet of the shop door. Just something to ponder.

Jonathan,

You have a good plan, a real common sense approach.  Know what you are getting into ahead of time and then hire a good electrician to do the work.  That's what I'd do and I am an electrical engineer.  Being an engineer in the electrical field doesn't qualify a person to be an electrician.  I have the greatest respect for good electricians and I learn a lot from them.

Who the heck told you that you can't run wiring through the open studs?  That is how almost all the wiring in you house is run. 

You've gotten good advice so far.  In most cases like this a sub-panel in the garage is the way to go, but it is really a case-by-case issue.  Extending vs running new is another case-by-case issue.  So much depends on length and cost issues.  If the cost is close, I'd run new.  Talk to an electrician who is actually there about alternatives.  Consider talking to more than one.

Given that you already have a lighting circuit out there, strongly consider leaving that in service even if you have a new sub-panel out there.  Could be an advantage when work on the new panel circuits is needed.  (but talk to an inspector if they will allow other circuits unrelated to the sub-panel)  If you ever run into a 'crunch' for house circuits, it sounds like you have a couple you could steal. 

 

Jonathan,

This is a hard question to answer. There are a lot of things that are going to be specific to your local code, as well as lots of codes to know already to do this project correctly. It sounds like you have plenty juice out there, so assuming it is done legally, safely, and to code, it would definitely be easiest to splice in there and continue to a sub-panel in your workshop.

But this is definitely something you should not do yourself. If you don't have the knowledge and experience, stay away from that part of the project. I can't stress enough that if you don't know what you're doing, you could get yourself or someone else killed.

As for the wiring, that's also a tough one to answer in a specific way. I don't want to say anything too detailed and go against your local code. I'd say first step is talk to the local inspector and see what will and will not pass with him.

Thanks everyone. I really appreciate the great responses.

It looks like it is time to talk with an electrician. There is a local one that my parents used on their house, and then my sister used too, that I think i can trust.

Unfortunately, my garage will not be a complete workshop so I won't have toys like joiners or planers, but i would love to get a drill press one day.

Thanks again,

Jonathan

I hope this copy/paste of this web site works.
It's got some good information that may be useful even though your hiring a Pro.

www.familyhandyman.com/DIY-Projects...unfinished

Jonathan - when you do talk to the electrician...ask if he'd install a sub-panel.  Something you can route new wiring from. 

Jonathan, these guys are absolutely correct about you being able to do a good bit yourself.

When you've got a plan set up with your electrician as to where your sub panel will go and what size panel will be installed, at that point give your inspector another call, ask if he will meet you at your shop and explain how he would like to see it done. Most inspectors appreciate being in the loop fromeven before you start until to finish, and would be happy to see your project and explain what they would like to see.

From that point you can carry on with what you want, putting in device boxes and if applicable, lighting boxes. As far as the size of the circuits, I personally don't run anything smaller than 12 gauge, which is good for 20 amp circuits. I don't like using 15 amp circuits because with 20 amps you can usually tap in and add a receptacle or light whereever you may want in the future. There is a decent price difference between 14 gauge and 12 gauge though, so that of course is your call. The inspector can also tell you how he wants it done, i.e. Romex, MC cable, conduit, etc., and you can pull the appropriate wire to each box. Definitely have your electrician around to tell him your plan and guide you through it with advice or give him a hand doing it.

If you know what kind of power tools or equipment you plan to get, you can research the amperage and run the appropriate circuit for that too. But if you have open walls, it's better to wait on that until you're sure what you're getting and where you want to put it.

If I missed anything you are curious about just ask more questions, we're happy to help where we can.

Posted By gsacks on 07-06-2012 01:39 PM
Hello everyone.  I just signed up and would appreciate any help, advise, and suggestions.

I have never rewired a room before.  I have done simple things like dimmer switches, hang ceiling fans, and relocate outlets.

The scenario:  My three car garage is open studs and detached from my house.  I am converting the farthest bay into my workshop.  The are no reachable plug outlets, and very poor lighting.  The garage has two outlets on the ceiling for the garage door openers.  There is one outlet by the door that leads to the house (on the opposite side of my workshop), and two standard light/light bulbs on the ceiling.

The previous homeowner had an outdoor hot tub on the slab/back porch.  They ran underground wires (it looks professional, but I don't know) from the breaker to the slab.  These are TWO dedicated 50 amp breakers.  I'm pretty sure that is more power than I will ever need.

I want to add two florescent tube hanging lights above my workbenches (I built two 6' workbenches that run the length of the last bay).  I am considering using a 3 way switch for the lights so I don't know if I can run them off my current wiring.  I want to add at least 4 plug outlets.  I will also have one additional non GFCI outlet dedicated to a fridge.  I have a portable Ryobi table saw.  I use cordless tools, but I have a corded drill and miter saw.  I plan on buying a router, compressor, etc.....someday.  I will probably use a mix of 15 and 20 amp outlets.  I only want to do this once, so more is better.  I will mainly be doing wood work/carpentry.

My thought is to tap into the wires from the hot tub and extend the underground conduit to the garage, about another 15' of cable, and connect them to a sub panel that I will run all my new wiring from.  The wires from the breaker to the tub is probably 75'.  My estimates are conservative, but I will measure them this weekend to make sure.

I thought I would find a website that will show me the correct way to wire the garage and then probably have an electrician look at everything and do to the final hook-up.  From the little research I have started, it seems i cannot run wire through the studs on an open wall.  Therefore my wiring requires a lot more wire.

I'm sure I have left plenty of details out.

Please ask as many questions as you would like.

Thank you all for your assistance.

Jonathan

Hi Jonathan,

I think "all" missed on this...   Your "tub" seemed to be about 15' from your garage. You mentioned extending the underground conduit to the garage.

Let me clarify something here; you do not want to have that cable spliced in the middle or anywhere if you intend to have it buried. All splices must be accessible. Logic to this is if something goes wrong any and all points of splices or taps can be accessed for inspection or maintenance.

In you case, you would need to turn that hot tub electrical termination point into a junction box and extend the line from there to the garage.  You could NOT have both the hot tub and the garage on that line. But to me it sounds like you already removed the hot tub.

If there are two 50 amp breakers and two 50 amp feeds from the house, you may be able to pull one out and use the wire to continue on through to the garage.

Is 50 amps enough? In my opinion, and unless you are considering electric heat, it should be enough for a one-man wood shop.  If you plan on having a general shop, one that may include a welder, well that 50 amps ain't gonna cut it.

I'm not sure, but it may be that the hot tub is using 220v 50A, at which point you couldn't pull one of the wires if the tub was still being used. Anyway, if he is pulling and reusing the feed to a hot tub that is no longer there, why not re-route the whole feed to the garage and feed a subpanel via what I suspect is a 220v 50A feed?

As far as a welder, that depends on how powerful it is and what you're running at the same time also. What I mean is that it's unlikely one person would be running their wood tools and a welder at the same time, and also unlikely he would be welding structural I beams or something like that.

I am not an electrician, just interested. Please have someone else check my advice, don't just use it.

Just my opinion...
I would get the electrician to run a new panel to the garage. I thought I had enough electric until we purchased the camper, you never know so be prepared and do it now while the walls are open ( cheaper that way).

Sounds like you have a good plan and good advice. Although am still unsure why you couldn't run wiring through the studs. If you do, buy those metal protector plates and put them in front of the wiring. In case you decide to enclose the walls, you won't screw or nail into the wires. Vertical runs of the wiring should lay near the middle of the stud too (front to back). same nail/screw concern if you replace siding or attach something to the outside and miss the stud.

The work of running wires and installing boxes is doable for most fairly adept people. It's the knowledge/game plan that is the difficult part.

Awesome, I really appreciate all the great replies.

Having access to the splice is a good piece of advice. Thanks.

I was under the impression that if I am not going to enclose the walls I cannot run the wires through the studs without the metal conduit. I don't plan on using the metal conduits.

I have bookmarked the link to the DIY unfinished garage.

Correct, the hot tub has been removed.

I also agree that one 50A is plenty, but as stated, just in case I need more juice for an extra addition/installation, I will run both.

I was hoping the electrician would know all the code requirements, but it seems an inspector is needed too.

Thanks again everyone. I truly appreciate your input/advise.

I knew Gerry (and Bompa?) would be along to help you solve this one.

On a project like this it is worth it to have an inspector (as long as they are truly qualified), as they can help you avoid future problems be getting it right the first time.

As far as how much power is needed, you need to figure the requirements for what you will be using.

Your tools and light fixtures should have labels stating the required supply. (i.e. 120v 20amp). Then figure what will be running at the same time.

If you have a compressor running, plus a dust collector along with a table saw, then add in your lighting you will need more power.

The last shop I had, had 100a service and could have used 200a.

I agree with woodchuck. If you have any 220V motors on your equipment and they start at the same time, you may be popping breakers. I had 50 amps going to the barn from the house with overhead service. I happened to start my table saw and had the compressor come on when my son struck and arc with the welder. It popped the breaker in house that feed the barn. I talked to the electrician that installed our new 200 amp service into the house a year ago. I asked if I could install an100 amp breaker for the barn. He came out to our place and said that the wire going to the barn would support 200 amps so he had a breaker with him and installed it into the new panel. I have not had any problems with the breakers since then.

Always plan for expansion. Larger panel, larger main line, and larger main breaker. Times change and so do the tools you have. What is adequate now, might not be in a few years. Do you have kids or expect to have kids in the future? If so are you going to want them to be with you in the shop learning and helping you? More people in the shop, more power is needed.