Garage wiring estimate

[K8096]

I have two estimates from experienced electricians to set up a 20 space 100 amp box out to a new constructed 25 X 50 ft attached garage. The problem is the main box in the house is almost 100 feet away, so it's a lot of wire, and I want it run in conduit. The first estimate was $1000 and that was without running it in conduit. The 2nd estimate was $1300 and that was with conduit. This is just running the main wire out, setting up the box, and installing a few outlets to get me started. It's not wiring the whole garage. Both electricians are independent and not part of a large company. I'm smart enough not to try to do it myself becauce I don't want to burn the garage down. What do you think of these estimates? I was hoping for cheaper, like $600 - $700, but maybe I'm behind the times.

[Bhigdog]

Doing what you describe is stone boat simple and can be easily and safely done with the help of available DIY books. If you buy the materials from an electrical supply house rather than a big box store you may pay a bit more but I've found the counter men to be a font of knowledge and only too glad to help with material selection and helpful hints and advice...........Bob.

Edited August 9, 2010 by Bhigdog (see edit history)

[1937hd45]

I hate the smell of electrical smoke, after I play with wire.

[Bhigdog]

The immutable law of electrical components is that once you let the smoke out you cannot put it back in..............Bob

[51dyno]

Have you looked at a seperate meter - service for the garage???? that way you can get a lot of juice and not worry about power drain for the long run.

[Guest fordv840]

I have two estimates from experienced electricians to set up a 20 space 100 amp box out to a new constructed 25 X 50 ft attached garage. The problem is the main box in the house is almost 100 feet away, so it's a lot of wire, and I want it run in conduit. The first estimate was $1000 and that was without running it in conduit. The 2nd estimate was $1300 and that was with conduit. This is just running the main wire out, setting up the box, and installing a few outlets to get me started. It's not wiring the whole garage. Both electricians are independent and not part of a large company. I'm smart enough not to try to do it myself becauce I don't want to burn the garage down. What do you think of these estimates? I was hoping for cheaper, like $600 - $700, but maybe I'm behind the times.

As an electrician I can tell you that is a fairly decent price. Two things I will comment on,

1. Go with a 200amp service on a garage that big if it is also a shop. If it is just for storage and all you will have is lights then 100A would be adequate but not ideal.

2. Definately go with the conduit.

Good luck, sounds like a nice size garage.

[Alfa]

Here in the UK it is actually illegal to do an installation like that yourself. It must be, at the very least, checked by a certified electrician. Which is a real nuisance.

[Bhigdog]

Here in the UK it is actually illegal to do an installation like that yourself. It must be, at the very least, checked by a certified electrician. Which is a real nuisance.

It's getting that way here. In many districts the work may be done by the owner but it must pass an inspection. Some places there is little regulation............bob

[DavidAU]

In Australia and New Zealand where the power is all 240 volt, all electrical work must be carried out by a registered electrician. It is illegal to do it yourself. 240V kills.

If the power supply to your shed is going to be underground you could install the conduit yourself with a draw wire through it so the electrician can pull the cable through and that would lower the price quite a bit. Feed the draw wire into each length of conduit as you are installing it.

David

[Barry Wolk]

I too, am an electrician and that's not a bad price. However, the main feed between house and garage is pretty basic DIY stuff. You should be able to get a "Homeowner's permit" which will allow you to do the bull work yourself.

If you don't plan on future trenching in the area of the cable use direct burial conductors.

Just so you know, the system in the garage will be considered a sub-panel and will require a separate neutral and ground, so you'd be burying 4 wires.

[K8096]

Barry,

When we poured the floor we pounded a metal rod into the ground that you buy at Lowe's for the ground for the subpanel. The concrete floor was poured around it. It's about a 4 foot rod and we got it about 2 1/2 - 3 feet pounded into the ground. Correct me if I'm wrong, but I'd be running three wires. Hot, neutral, and ground. The box will be grounded to the rod. We're running the main feed wire on the basement (of the house) ceiling, and through the attic of the existing two car garage to reach the new garage addition. We're not running it outside.

Question. I see you can buy main feed line that has the three wires in it at the big box stores for about $1.50 foot. However it seems the electricians I've talked to want to buy each wire seperate. Any reason for this?

[JZRIV]

Are you digging the trench or are they? If they are doing the digging thats a "really" good price.

If you are not comfortable doing electrical work don't even consider it. If you have a qualified friend or neighbor to guide you then thats OK. You do the labor but they check in and make sure its being done right and the correct materials are purchased.

If your soil is primarily rock free like say clay or sandy soil you do not need conduit assuming the area is not being driven over by vehicles such as a driveway. Even if you have a few rocks just insure they are cleared away from the wire when backfilling. Direct burial wire is made for direct burial and can withstand cuts in the insulation from normal pressure from settling, freezing/thawing etc, but you always want extra precaution such as conduit any time the soil will be compressed by a vehicle or whatever.

On the single conductor vs grouped wire question. When running in conduit, typically its less expensive and easier to pull individual conductors. If individual conductors are used for direct burial they should be of the type that are a group of 3-4 wires twisted together so it lays like a single cable just without an extra outer protective sheath.

Edited August 11, 2010 by JZRIV (see edit history)

[Barry Wolk]

Barry,

When we poured the floor we pounded a metal rod into the ground that you buy at Lowe's for the ground for the subpanel. The concrete floor was poured around it. It's about a 4 foot rod and we got it about 2 1/2 - 3 feet pounded into the ground. Correct me if I'm wrong, but I'd be running three wires. Hot, neutral, and ground. The box will be grounded to the rod. We're running the main feed wire on the basement (of the house) ceiling, and through the attic of the existing two car garage to reach the new garage addition. We're not running it outside.

Question. I see you can buy main feed line that has the three wires in it at the big box stores for about $1.50 foot. However it seems the electricians I've talked to want to buy each wire seperate. Any reason for this?

They wouldn't be running individual conductor in your house unless they were an approved cable enclosing the conductors.

You had better check with your local authority, but I believe sub=feed cable (4 conductors) will be required. You need to find that out before you do anything.

If they were running pipe through your house, that's an especially good price.

[Ron Green]

Per the National Electrical Code: For 240-volt used as a sub-panel you will need 4 wires. 2 - hots / 1-neutral / 1-ground with the correct rated cable, be it direct buried, overhead, or in conduit. The reason you carry the additional ground wire is that your neutral (white wires) and bare ground wires need to be separated at the subpanel via separate / different terminal blocks. On the main panel they use the same block. The neutral bonding screw that comes with the panel is not used on a subpanel installation. Only at the main panel or 1st disconnect switch is the neutral allowed to be bonded.

You can not use the gray covered cable (SE / SER) in a underground conduit as it is not rated for water. Your ground rod sounds like it may be to short? I would take a resistance reading just to verify. The separate ground rod is required on electric services that are in out buildings, etc. Not attached to the structure your main service is serving. Also some municipalities require an electrical inspection. If you decided to do your own wiring have an electrician check it out. Not only can you be killed you can burn it down including loss of all the contents.

The price they quoted sounds reasonable however 100' away is a long distance and will more than likely require a larger wire (voltage drop needs to be calculated verses load). 100 amps isn't much for a garage. A 100 amp breaker trips at 80 amps.

Edited August 11, 2010 by Ron Green (see edit history)

[Layden B]

DAVIDAU

120 volts here in the USA kills more people than any other voltage. Yes it is less lethal but it is sooooo common.

[K8096]

Why would 100 amps not be enough? The one electician I spoke with put it this way: how many things are you going to run at the same time? I might have 20 power tools, but you can only use one at a time. Lets take a worse case scenario: In the garage there will be a large two stage compressor that draws 25 amps, a glass bead machine with a small electic fan motor on it, a bunch of florescent ceiling lights, a garage door opener, a small fridge, and then a wide assortment of power tools. If I ran the compressor, the glass bead machine, all the lights, the fridge, and opened the garage door while using a drill press, is that going to be 80 amps?

[joe_padavano]

Here in VA, a homeowner is allowed to do wiring on his/her own property without being a certified electrician. This really is dirt simple wiring, and I recently did exactly this wiring in my garage - which is nearly 500 ft from the house. I did the voltage drop calculations and ended up using 4/0 USE cable (direct burial cable) to minimize the voltage drop.

If you are not comfortable doing this wiring, you can string the wires and install the boxes yourself and just have the electrician make the connections. That should save a few dollars.

[Ron Green]

Why would 100 amps not be enough? The one electician I spoke with put it this way: how many things are you going to run at the same time? I might have 20 power tools, but you can only use one at a time. Lets take a worse case scenario: In the garage there will be a large two stage compressor that draws 25 amps, a glass bead machine with a small electic fan motor on it, a bunch of florescent ceiling lights, a garage door opener, a small fridge, and then a wide assortment of power tools. If I ran the compressor, the glass bead machine, all the lights, the fridge, and opened the garage door while using a drill press, is that going to be 80 amps?

I did not say 100 amps may not be enough (80 amps actually). Add an electric welder, a lot of lighting, air compressor, AC or electric heat for a separate room possibly, etc, etc you could be pushing it. I don't have a crystal ball to know what you are visualizing.

[JZRIV]

Why would 100 amps not be enough? ?

100 A will be more than adequate. You are exactly right, it all comes down to actual demand of the equipment that will be used. With 100A you will still have excess capacity for future loads not yet envisioned.

[bhclark]

The only other thing to consider is that it's much cheaper to run 200A now than to upgrade the 100A to 200A later.

I'd get a quote on both, then make the decision.

[Guest dokks6t9]

This is why you have to have friends. I have plumber friends, lawyer friends, and electrician friends.I recently asked my electrician friend to put power into my small barn. 2 four foot fluorescent fixtures, 2 outlets with GFI, underground conduit, wiring, and knocking the hole in my house foundation. My cost, including materials and installation, was $20 bucks, plus lunch.

[Guest Xprefix28truck]

Maybe I am missing something here. If he is running this sub box off of his existing house circuit, then you won't want to pull anymore than 100 amps for a sub box. Am I right in thinking you wouldn't want to try a 200 amp sub? Seems this would be to taxing on the existing house circuit. My garage is a 100 amp sub off of my house circuit. Am I thinking wrong?

[Barry Wolk]

What I was suggesting is to feed the garage with a new 200-amp service drop and sub-feed the house from the new location.

Edited August 15, 2010 by Barry Wolk (see edit history)

[Guest Xprefix28truck]

Ok... that sounds reasonable. It was suggested by someone else also to put in 200 verses 100.........

[K8096]

I just thought of something. Down the road, I may want to install a ceiling mounted commercial type electric heater. Garage is 1250 sq feet , but i might install a thick plastic "curtain" in order to heat just 1/2 of it. Anyone have one of those currently installed? How many amps do they draw? I know one thing I don't want is a natural gas heater with a flame. A friend has wall mounted ones where you can see the flame just standing in front of it. I don't think having an open flame in a garage with chemical vapors (gasoline, laquer thinner, carb cleaner, ect) is a good idea.

I may have to do more research here and hold off until spring on doing this wiring project. I want to do it once and do it right.

I appreciate everones comments and suggestions.

[Barry Wolk]

If you're thinking of ceiling radiant heat panels, they will do a great job since they warm the objects in the room, not the air. Grainger's sells a 2 x 4-foot radiant panel that consumes 750-watts. You could put two on a 20-amp circuit. You'd probably need 10 of them.

Had I had it to do over again I'd run PEX tubing in the concrete and heat the floor. It's cheap and efficient. All you need is a hot water source, thermostat, zone valve and tiny pump.

The rest of my house is heated hydronically and I love it.

[Guest fordv840]

I have a Dayton g73 heater from Grainger in my garage, 24x24 with 12ft ceilings in southern PA and it will make it like Jamaica in there if you want it. My garage is insulated all around including the door. The current draw of the heater should be listed in the specs.

Someone else commented on weather you can run a 200A sub from a 100A panel. No you cannot. Your subpanel cannot be rated higher than your main panel. However I still recommend 200A service to a garage/shop. If it is strictly a garage to park cars in you will have no issues with 100A but I always seem to have too few outlets and 2 phase power in every garage I have ever had.

[Guest fordv840]

If you're thinking of ceiling radiant heat panels, they will do a great job since they warm the objects in the room, not the air. Grainger's sells a 2 x 4-foot radiant panel that consumes 750-watts. You could put two on a 20-amp circuit. You'd probably need 10 of them.

Had I had it to do over again I'd run PEX tubing in the concrete and heat the floor. It's cheap and efficient. All you need is a hot water source, thermostat, zone valve and tiny pump.

The rest of my house is heated hydronically and I love it.

I agree 100% I had radiant floor heat in my last shop in NH and it was great, nice and warm and the floor was comfortable to lay on. It did take a while to heat up however so you have to maintain a certain temp all the time but it didn't seem to cost an arm and a leg to do that. I ran mine off an oil fired furnace that heated the rest of the house as well. Radiant heat is also the most comfortable I think, you don't get the "breeze" as with the electric heater I have and the temp is more stable. I just wanted cheap easy heat in my new garage so I went with the G73.

[K8096]

I did 2 inch thick high density foam insullation sheets under my conctere floor and I do have the fully insulated garage doors too. Eventually I'll insulate the whole garage as well, including the ceiling (after wiring done) and I'll use the 5/8 inch thick fireproof drywall. I work full time and have 2 little kids so it will take a few years to finish.

My house was updated to 200 amps a couple years ago, so I'm definately running a wire from the house to the attached garage.

I looked up the Dayton G73 heater. It takes a dedicated 220 line and needs a 30 amp curcuit. Looks like actual amp draw is 21 amps. It heats up to 500 sq feet, so if I got one of those, I would for sure have to "curtain" off 1/2 the 25 X 50 garage. Cost is about $400 plus $18 for a ceiling mount kit. Not bad. I'd probably just have to make sure I didn't run the large compressor at the same time as the heater.

A friend of mine worked at a Ford dealer and they had just got in a brand new ceiling mounted commercial grade electric heater. The dealership went out of business before it could be installed so he got it for a song and installed it in his 1500 sq ft garage and loved it. This was back in the early 1980's.

[Guest 1hooligan]

You should be able to rent a trencher, much like you use to install a new sprinkler system.

acquire the necessary wiring, and the correct conduit (your local building department maybe able to assist you in which type to use. If your electrician is will to work with you, you install the boxes, and pull the wiring in the garage, and he does the connections. Thats what I did and I was able to cut the cost down by about a third.

[Guest dorramider7]

In Australia and New Zealand where the power is all 240 volt, all electrical work must be carried out by a registered electrician. It is illegal to do it yourself. 240V kills.

If the power supply to your shed is going to be underground you could install the conduit yourself with a draw wire through it so the electrician can pull the cable through and that would lower the price quite a bit. Feed the draw wire into each length of conduit as you are installing it.

David

I too, am an electrician and that's not a bad price. However, the main feed between house and garage is pretty basic DIY stuff. You should be able to get a "Homeowner's permit" which will allow you to do the bull work yourself.

If you don't plan on future trenching in the area of the cable use direct burial conductors.

Just so you know, the system in the garage will be considered a sub-panel and will require a separate neutral and ground, so you'd be burying 4 wires.

[Guest Jim_Edwards]

I would gather from the original post date of this thread the project may be well beyond the planning stages and perhaps even the construction stage but for persons who might be also entertaining a similar project a few planning hints that may save a lot of money and perhaps frustration in the long run.

Before planning any such project it will be wise to check local requirements for necessary permits, even if you live in an unincorporated area outside of an incorporated area, but within 1 to 5 miles. Extra territorial jurisdictions may extend their permitting authority to your location depending upon the state where one is located.

Secondly, check with your insurance agent. Your new building will not necessarily be covered by present home owners insurance. Additionally, provisions of the policy could be voided if any alterations have been done without appropriate permits or electrical work not having been done in accordance applicable local codes and/or the National Electric Code.

Third, previous comments on help from the counter guy at a distributor or retail store should be taken with a grain of salt. There is every likelihood that person is not and expert on building codes in your particular area and it is very unlikely they are licensed in any trade, otherwise they wouldn't be doing what they are doing. Probably knowledgeable about the quality of different products they sell, but not necessarily competent on application.

Things to think about!

Climate always plays a roll to the extent of any anticipated heating and A/C desires or requirements in the long run. Then there is the issue of what shop equipment will or maybe added in the future, i.e.; compressor, TIG or MIG welder, lift(s). A typical shop for hobby restoration work will need at least three maybe four 230/240 dedicated runs in place initially to be on the safe side even if the equipment isn't to be purchased and installed immediately. There is never such a thing as too many 110/120 wall outlets particularly along walls where work benches may be placed and in my mind no more than two to four outlets in a shop should be placed on the same breaker to avoid those unwanted breaker trips. The amp draw of many bench mounted tools will often be greater than you might think. Two electrical devices simultaneously on and each drawing more than 10 amps will indeed trip a 20 amp breaker!

Ceiling light circuits should not be placed on the same breaker with wall outlets in my mind unless one doesn't mind looking for a flashlight in the dark because you can't see the breaker box after a breaker trips. (you will eventually by accident overload circuits and trip breakers if a short in some device doesn't do it for you). Wire of the correct gauge for a run and boxes are cheap in comparison to having to correct oversights in the future; and beside who wants to find out the hard way they should have spent a few more bucks in the beginning to be able to use that suddenly desired or needed electrical tool.

Most of all don't let doing something for less override common sense and good practice. The "5 P" theory of "Proper Planning Prevents Poor Performance" should always be foremost in the mind.

Just sayin'

Jim

[Barry Wolk]

Also, consider an emergency light or two. When the lights go out it's nice to be able to find your way out.

[Guest dokks6t9]

I would gather from the original post date of this thread the project may be well beyond the planning stages and perhaps even the construction stage but for persons who might be also entertaining a similar project a few planning hints that may save a lot of money and perhaps frustration in the long run.

Before planning any such project it will be wise to check local requirements for necessary permits, even if you live in an unincorporated area outside of an incorporated area, but within 1 to 5 miles. Extra territorial jurisdictions may extend their permitting authority to your location depending upon the state where one is located.

Secondly, check with your insurance agent. Your new building will not necessarily be covered by present home owners insurance. Additionally, provisions of the policy could be voided if any alterations have been done without appropriate permits or electrical work not having been done in accordance applicable local codes and/or the National Electric Code.

Third, previous comments on help from the counter guy at a distributor or retail store should be taken with a grain of salt. There is every likelihood that person is not and expert on building codes in your particular area and it is very unlikely they are licensed in any trade, otherwise they wouldn't be doing what they are doing. Probably knowledgeable about the quality of different products they sell, but not necessarily competent on application.

Things to think about!

Climate always plays a roll to the extent of any anticipated heating and A/C desires or requirements in the long run. Then there is the issue of what shop equipment will or maybe added in the future, i.e.; compressor, TIG or MIG welder, lift(s). A typical shop for hobby restoration work will need at least three maybe four 230/240 dedicated runs in place initially to be on the safe side even if the equipment isn't to be purchased and installed immediately. There is never such a thing as too many 110/120 wall outlets particularly along walls where work benches may be placed and in my mind no more than two to four outlets in a shop should be placed on the same breaker to avoid those unwanted breaker trips. The amp draw of many bench mounted tools will often be greater than you might think. Two electrical devices simultaneously on and each drawing more than 10 amps will indeed trip a 20 amp breaker!

Ceiling light circuits should not be placed on the same breaker with wall outlets in my mind unless one doesn't mind looking for a flashlight in the dark because you can't see the breaker box after a breaker trips. (you will eventually by accident overload circuits and trip breakers if a short in some device doesn't do it for you). Wire of the correct gauge for a run and boxes are cheap in comparison to having to correct oversights in the future; and beside who wants to find out the hard way they should have spent a few more bucks in the beginning to be able to use that suddenly desired or needed electrical tool.

Most of all don't let doing something for less override common sense and good practice. The "5 P" theory of "Proper Planning Prevents Poor Performance" should always be foremost in the mind.

Just sayin'

Jim

GREAT advice!!!

[Scotts_DG8]

When I had my house upped to a 200 Amp service and a separate 100 Amp service put in my garage there was already a single 12/2 run out to the garage that ran two 4 ft florescent lights and two outlets on its own 20 amp breaker in the house that I chose to leave in place for the alternative/backup power to the garage. It’s come in handy a couple times when I’ve shut the subpanel breaker off in the house while doing other garage wiring. But then again, it wasn’t a planned action just taking advantage of what was already there.

Oh, I did dig my own trench and bury my own conduit (about 80 ft distance) but had the electrician run the wires through the conduit. And another thing that I decided to do was to bury a separate conduit for a run of internet and cable to the garage at the same time (you can't run these with the power run), something that some others may want to consider. I had used my wireless link on my PC a couple time in the garage with so so results, having a direct link really makes a big difference. Just some other things to consider if you’re going to run your own conduit, a second/separate conduit could come in handy. Scott...

[oldIHtruck]

With the cost of copper wire and the cost of material, the $1300 bid is a bargain.

When you figure the cost of three legs of wire, ( two hots and a neutral), plus a ground wire running back to the main panel, that is a cheap price. There should be a ground run back to the main as part of the N.E.C.