240v Garage Circuit Installation Cost?

[LarryG]

Ah. Well, I guess you'd have to chalk that up to the writers of those other manuals not being as thorough as the guy who wrote the table saw manual. There's nothing magic or different about the 15 amps the table saw draws versus the 15 amps something else draws.

If the table saw manual says, or implies, "One breaker, one wire, one receptacle! No exceptions!" -- that's an example of the manufacturer's lawyers being in Full CYA Mode. Having only one outlet would eliminate any possibility of their being anything else running at the same time as the saw, but, again, additional outlets won't hurt a thing as long as there is no load on them when the table saw is running.

[Hellrazor]

This question isn't too hard to deal with.

Whats the distance to the garage?
How many AMP Service do you want run out?
Do you want to pull slightly larger wire in case you want to bump the panel up at a later date?
Are you going to use THWN and conduit or UF buried cable?
Are you going to buy a full size 100A panel or a 40-60A mini panel?
How many breakers do you need in the panel?
Do you have a suitable breaker for your current panel or do you need to buy one?

You want to ground the garage with its own ground rod plus the ground back to the house. Do not bond the neutral and ground bars in the garage panel.

I ran #6 red,black,white #8 green in 2" conduit 120' to my workshop. Right now its fed with a 30A 220 until i upgrade the main box to 200A. Then i am going to switch it to 50A.

Outright guessing a cost is impossible since it really depends on the wire size, panel size and length of the run. Conduit vs no conduit also changes the cost. Larger buried cable is more expensive then THWN conduit together. Time to complete the job depends on your experience, skill and knowledge. For what i did to my workshop so far, its been around $500 doing the work myself.

BT3100 should have its own dedicated circuit. You can share this circuit with other tools not in use while the saw is running. Basicly that means a dust collector or shop vac has to be on another circuit. Remember to stagger the loads of the 110 circuits to which leg they fall on.

Also remember a garage/workshop falls under the GFCI protection requirements. So you will need to install either GFCI breakers or outlets.

[maxparot]

quote:Originally posted by realeyz

I understand what you are saying Maxparot but my question is why does my Table Saw require its own circuit but my circular saw and miter saws don't? They all draw the same 15 amps.

I'd say Larry has probably got it correct just some technical writers and their lawyers covering their butts better than others.

Another explanation may be:
a circular saw with a 15 amp motor only has a 7 1/4" blade it may never need to draw it's full rated power due to more mechanical leverage.

Similarly even thought a 10" miter saw used the same blade as the tablesaw it is only used to chop through the workpiece quickly. It is only under load for a short duration.

In comparison a tablesaw with a 10" blade may be used to rip lumber. it is therefore required to be under full load for a longer duration and could heat up it's supplying breaker and cause it to trip if used with another device on the circuit.

If anyone is wondering how I have come to this conclusion.
I've worked in some sort of electrical technology since I was in high school many years ago.
I was originally in college for electrical engineering but ended up changing my field of study.
My wife is an electrical engineer and we often discuss things that go on in our workplaces.

[stewchi]

Price out all the parts at home depot, assume $85 to $100 per hour is reasonable for an electrician (that is the going rate in Chicagoland). With these to figures the only variable it how long it will take. You can probably make a swag on that or we could help given more info on the situation. That should tell you what a fair price should be. Almost any quote you will get will be negotiable. I would recommend no less than 3 bids for the job, you may see big difference between the prices. You could easily save a few $100 by shopping around. If you are going to get a permit for the job (which more reputable contractors will require) make sure you add to the contract that they are responsible for all working being up to code rework due to failed inspection will be done at no additional charge.

[coach]

Go to the library and get a good book on electrical basics. It should at least help you get the wires run and connected to the outlets. If you are still unsure, you can hire an electrician to make the connections to the panel. I would suggest learning to do it, and learning to do it right. It will be a valuable skill that you will be able to use for the rest of you life. It is kind of like changing oil or filling up with gas; why pay someone else to do a job that you can learn to do for yourself.

[Kristofor]

quote:Originally posted by maxparot

quote:Originally posted by realeyz

I understand what you are saying Maxparot but my question is why does my Table Saw require its own circuit but my circular saw and miter saws don't? They all draw the same 15 amps.

I'd say Larry has probably got it correct just some technical writers and their lawyers covering their butts better than others.

Another explanation may be...

I'd be more pragmatic about the rationale... It may be reasonable to expect a user to run a dedicated circuit for a large (mostly) stationary powertool like a table saw. However portable tools are much less portable if you need to pay an electrician whenever you want to use them in a different room...

For instance if Hoover claimed you needed to run a dedicated vacuum circuit to every room in your house because they pull 14.5A on some of their models, this would not seem very practical and may well reduce their number of sales (and in general my vacuum runs longer than my saws).

However, if I was going to only ever use my vacuum in one place, I probably would wire a dedicated circuit so I didn't have to worry about having enough juice or popping a breaker.

Kristofor.

[gjat]

maxparot is correct. I'm not a licensed electrician, but I've run electrical projects for twenty years. (LOL) Actually, I do industrial stuff, not residential, but principles are teh same. If you have to read a book, don't do it. Ask around for an electrician friend if you want to go cheap, but don't cheap out. You are wiring the same building you and your children sleep in. It's not worth saving $500 if you aren't 100% sure what to do. If you are asking what to do to make sure the electrician does all he's supposed to do, that's fine.
My recommondation to do it right, is to tap off your Main Lugs and provide a sub-panel for your shop area. Make sure your sub panel has a Main Circuit Breaker, not Lugs. From there you can provide seperate circuits for what you want. I would definitely hire an electrician, because it would be best to yank the meter to shut the power off and the Power Co. might want an inspection to replace the tamper tag.

110 vs 120 is just what the voltage the power company is providing on 1 leg (phase to ground). It's actually somewhere between 103 and 128 volts. 220 is just two hot legs (phase to phase), so it may be 206 to 256. Any good motor will run fine.

The reason why a table saw should be on a dedicated circuit, is to avoid voltage drop with other things running and having the motor stall then kick back on when the Fridge compressor cycles while you are cutting. Much more dangerous than your circular saw.

If you do it yourself, oversize the wire, don't oversize the breaker. Avoid splices like the plague. Use the screw terminals on switches and receptacles, not the quick push grips. Make sure all your grounds and neutrals are well connected, pretend they are even more important than the hot leg.

[stewchi]

I agree with the above with the possible assumption of running of the main lugs, I am not sure if that is code in all areas, to branch of the main lugs or to branch from the meter. It depends on your AHJ (Authority having jurisdiction).
It is more typical to put in a breaker in the main panel and run the subpanel from that breaker. Remember for subpanels the neutral and the ground must remain isolated which often requires the purchase of a ground bus to add to the panel, and that little green screw on the neutral bus must be removed to insure the neutral bus stays isolated from the panel and ground. Ground and Neutral are only supposed to be tied together at the main panel or service entrance.

[Tom.Trout]

This is the panel feeding my shop. I'm realy not sure what to do???

quote:Originally posted by realeyz

For those who hired an electrician to install a shop 240v circuit. What did it cost and were you satisfied with the work? How many circuits did you get installed? What would you do differently if you had to do it over again?

Thanx
- todd

[gjat]

Tom,
I would not sleep at night with that in my garage. First thing I would do would be to shut it off from where it's fed. According to the size and condition of the feed conductors, I would but in a load center with a main CB sized accordingly. I would also make sure you had a CB disconnect for that feed at the main panel that feeds that sub-panel.
To clarify my earlier comment about coming off the lugs, never have unprotected circuits (without a fuse or breaker) running through your house. If you want a sub panel, tap off the lugs to another protected disconnect before you run your feed to your sub panel. If you tap into the load side of your main CB, you can easily over-load the main to your house. My quasi-professional advice is if you are adding more than 1 circuit, either have a local electrician do it for you, or have one inspect what you did (will do.) If you feel you can afford $500 in wood working tools, you can afford $500 for an electrician to do or inspect and serious modifications. I have seen way too many 'little things' short out electrical systems, destroy electrical equipment, melt, spark, flame, etc. Even low voltage stuff can do this. In a situation where you have saw dust, old dust, wood, locations in basements and attached garages, proximity to flamables such as stains, mineral spirits, etc., you guys are scaring the **** out of me.

[Tom Slick]

In my facility, each sub panel has a breaker in the main panel it branches from that is rated for the sub panel. each sub panel doesn't have it's own main at the sub panel.
as gjat was eluding to, if your current main panel is 200 amp service and you currently have 180 amps worth of breakers in it you can't simply add a 60 amp sub panel and be ligit. if you have 200a service and only 100a worth of breakers you can add 60a more then it will be ligit. all of your breakers must in the system must add up to less then the main service to your house.

[maxparot]

Actually you can have breakers totaling far in excess of the services main breaker legitimately.
I had a significant amount of electrical work done at my home this past summer. I was all done by licensed electricians and was inspected by a town building inspector.
After all was done I have ended up with 200 amp mains with the normal amount of household curcuits for HVAC, electric range, refrigerator, lighting, outlets,
100 amp subpanel for my shop,
50 amp subpanel for my pool and
50 amp subpanel for my hot tub

The point is that the individual breakers rarely see more than 75% of their rated loads. Some don't even see 10% and your mains seldom see 50%.
If you used 90% of each breakers capacity (with even 100 amp service) on a regular basis your electric bill would be astronomical.

[gjat]

max,
I would be surprised if he did 'sub-panels' that were 50 amp, one would just use breakers for the circuit and then you would have a means of disconnect out by your pool or hot-tub. There are more than 1 way to skin a cat. Like I said, I'm not a residential electrician, my reference would be how it would be done in an industrial/commercial set up. Safety is very important and electrical demand is anticipated to be a little higher than in residential. Please, have a residential electrician check out what you did or what you are going to do. Don't just go by the advice of a Borg salesman that worked in electrical for 20 years. That's different from being experience AND a license holder, up to snuff of current code. I've seen wire nut connections melt, over-striped terminal connections short, switches fail and melt, connections come out and short, and thermo-breakers (what you call circuit breakers) fail to trip. Breakers you trip alot can fail in the on or off position when they wear out.
In a commercial application, a sub-panel would come off a main distribution panel. The dedicated feed would have overload protection at the distribution panel and feed the sub-panel. The sub-panel would be in the room with the equipment (your shop) sort of like what Tom has. From there, you would feed your different circuits since your sub-panel would be a distribution panel. For safety and convenience, I would have a main CB at the sub-panel for the times you want to work on the panel. In your sub-panel, I would then have my seperate 220 or 110 circuits to my devices. Make sure everything is installed properly, all wires are connected neatly and correctly, etc. You want ot keep dust of it. The danger of electricity is heat and spark. Breakers trip on heat caused by load AND / OR inability to dissapate heat. That's why there are 'fill' rules for the number of conductors or devices in an enclosure.

Don't do it if you aren't sure it isn't safe for you or anybody else who sleeps under the same roof.

[maxparot]

Seems the Hot Tub is a special case it required that a subpanel be mounted within view of the tub yet not less than 6' away. It also requires a GFI breaker and you are not allowed to use multi conductor cable so it must be run entirely in conduit. This was all a code requirement that was inspected by a town building inspector.
The pool also required a GFI breaker but could be done from the main panel if I had the space for breakers but since I did not a sub panel was added for expansion.

[stewchi]

From the looks of it, you have two disconnects and 4 circuits on that old fuse box and a service wire coming in, the big gray one.
Like GJAT said what does the main house panel look like, is there a circuit breaker or fuse labled for this sub-fusebox, what size is it?
Can you tell us if the big gray wire has 4 conductors or 3? You will have to take the cover off the fuse box (With Extreme Caution) to get a good look. You can do this at the main panel (if this the were the wire is going) or at the sub-fusebox (the one in the picture) While your in there see if you can see any markings on the wire that would tell you the size AWG of the wire. If your lucky you can just replace the fuse box with a new subpanel (provided you have 4 conductors of the appropriate size wire feeding it). If your unlucky you will have to run a new wire from you main service to a new subpanel. There is a wealth on information available from people on this forum as well as electrical forums on the web. What ever you decide I highly recommend getting a permit from the local authority to do the work. That way it will be inspected and you can feel good about it. Installing a subpanel is not hard provided you follow the rules of the code. Not all areas will allow a DIY for this type of work, but most jurisdictions allow for the owner who is also the resident to pull permits and do the work themselves