# Electrical Help Needed



## Bigred15 (Dec 22, 2008)

My workshop can be divided into 3 sections. First you have the garage, which is where my woodshop resides. Then there is the storage room which is right next to the garage. Last you have my rec room which is upstairs and runs the entire length of the building. I have power run throughout the entire building, and the upstairs is heated. This summer I was planning to put an addition on the back of the building so I could relocate all the woodworking stuff back there and reclaim the garage portion. I preperation for that I decided to check the electrical, what I found was not good. First, to supply power, there is a underground cable run from the breaker box in the house to the one in the shop. The house unit is a 200 Amp box, with a 60 amp breaker for the shop. I'm not sure how many amps the box for the shop is. The 60 amp breaker made me wonder, but I have never had any problems. The shop is where its starts to get messy. Three of the breakers make sense, but the other don't. I have one 50 amp for the AC/Gas Furnace, two 20 amps tied together for a 220 outlet ran upstairs, and one 20 amp for the wall sockets upstairs. Thats pretty standard stuff. The other two breakers are not. First is a 30 amp breaker that is run into the storage room for lights AND wall sockets. This breaker also powers two of the wall sockets in the garage. Then I have another 30 amp breaker that runs lights AND wall sockets in the garage PLUS the lights that are upstairs!!! Knowing this, I am amazed that I have never blown a breaker in the woodshop. Especially when I run the jointer, shop vac and 6 florescent light fixtures all at the same time. Heck, just the jointer and shop vac combine for 26 amps. This can't be good for my tools. I don't know what to do. For sure I'm going to run some extension cords to use the sockets in the storage room to run some of my stuff. But aside from that I don't know what else can be done besides a total rewire. Help!!!


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## BHOFM (Oct 14, 2008)

You need to get an electrician to look at what you have.
Do not listen to anything anyone here tells you!


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## GeorgeC (Jul 30, 2008)

I agree that you need an electrician to review your status.

I doubt that it is as bad as you think. I would doubt that your shop vac and jointer combined draw 26 amps. Maybe if both STARTED simultaneously but not steady state running.

G


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## BORKBOB (Feb 9, 2009)

Hi Red,

Since you won't listen to me, I'll just ramble anyway:laughing:.

Some terms:

120 volt: one pole (of two) of typical residential electric service.
240 volt: both poles of typical residential service
Neutral: third wire provided by power company. Necessary for 120v. Not necessary for 240v.
Single pole: one side of service equipment, fed by one of the hots from power company.
Double pole: both sides of service equipment, fed by both hots from power company.
Grounding: system of wires (bare or green) throughout building that allow connection to appliance or equipment frames or enclosures. Normally does not carry current. Current carrying only when a fault exists. Entire network is attached to one or more grounding electrodes (rod or pipe) and/or metallic water pipes or rebar in concrete slabs. May not be found in services that predate early 1060's. 

You aren't blowing breakers because the breakers are too big. Breakers (or fuses) are sized to protect the cable in that circuit. First, the 50 amp for the air/furnace sounds too big. The A/C compressor (outside) will have a label on it that says something like "Max. fuse size" and I'll bet it's 25 or 30. Also, the 120 volt for the furnace should be a separate circuit, usually a 15 amp with 14-2 cable. 

Single pole (120v) circuits are fed by breakers that connect with only one side of the service panel and have only one wire attached to them to feed the circuit. 

Single pole 30 amp breakers are very rare in residential panels. Some smaller RV's and travel trailers use 30 amp single pole but I can't think of anything else. 

Double pole 30 amp breakers are common: dryer, water heater, A/C, built in range or oven.

There, I got that off my chest.

Now, LISTEN TO ME. You need to get this checked by a qualified electrician as soon as possible. Breakers that are too large for the cable in the circuit are a FIRE HAZARD. Drawing too much current thru a certain size wire can cause it to overheat. If this happens and the breaker is the right size, the breaker will trip. If the breaker is too big, it may allow the excess current to heat the wire to the point of ignition. You then read about it in tomorrow's paper. "Chief suspects faulty wiring". 

It sounds like changing the breakers to the correct size will be fairly simple. BUT, because this is such a basic error, I think the electrician should check the outlets and switches and any junction boxes. It looks like a "know it all" did this work, and they don't always limit their "expertise" to one place. 

Let us know what happens.


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## WDChew (Aug 31, 2007)

To just restate what was said above, a 30a breaker requires a minimum of 10ga wire.
12ga will handle 20a and 14ga will handle 15a.

Unless your whole garage is wired with 10ga (not likely) you have an electric heater running in your walls any time you pull more than 20 amps and you will burn the place down.


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## BHOFM (Oct 14, 2008)

To give you some idea, these guys are telling you right.

We have two 50 amp outlets in the study for the
computers, they have 8 gauge wire to them. That 
is like small water hose size.

The shop is all 10 gauge. with a 60 amp service to
the shop. It has 8 gauge to the panel in the shop.
It is all in conduit and is on the out side of the
walls. Several of the outlets are switched as well.

I can shut the shop off and not bother any thing in the
house.

You are dealing with the most dangerous thing in
your shop, make sure you get it right.

Buy a cheap table saw, but not cheap wiring.

BTW. my brother in law is a licensed electrician and likes
to spend my money. He did the study and shop for me.


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## Bigred15 (Dec 22, 2008)

Just got done talking to the electrician and we figured out what needs to be done. The 50 amp leading to the AC/heater only requires 30 amps max with a 17.2 constant. So that breaker will be switched out with a 30 amp. This will allow me to keep the same cable currently being run to the workshop eventhough we are switching out the box in the shop and the breaker that feeds the shop. The breaker will be upgraded to a 90 amp and the box will be a 100 amp. The two 30 amp breakers currently in the shop will be switched out for 20 amp units for the lights. Then additional 20 amp breakers will be installed for the wall sockets. Some additional wiring will also have to be run to keep the wall sockets and lights on seperate circuits. While they are at it, I am also having them disconnect the current 220 outlet and have a new one installed in the shop.


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## AZ Termite (Dec 20, 2008)

BigRed, To add to what has already been said, you stated you are going to use extension cords to run some of your stuff. You don't want to run any of your bigger tools with extension cords. If the cord is too small there will be power loss which will put more strain on your tool motors. The best thing to do is get an electrician to look at what you have and fix what needs fixing. You may be toying with disaster.


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## Bigred15 (Dec 22, 2008)

AZ Termite said:


> BigRed, To add to what has already been said, you stated you are going to use extension cords to run some of your stuff. You don't want to run any of your bigger tools with extension cords. If the cord is too small there will be power loss which will put more strain on your tool motors. The best thing to do is get an electrician to look at what you have and fix what needs fixing. You may be toying with disaster.


I'm was going to run extension cords to run the shop vac and my smaller tools. But that will not be needed in a few weeks because the electrician is going to fix all the stuff that I mentioned above.


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## BHOFM (Oct 14, 2008)

Make sure you get "good" cords, 12 gauge even
for the shop vac and such. 
14 gauge is fine for sanders and drills and small
tools as long as they are no too long.
I have a bunch of 12/3 ten footers that were thrown
out at school because they had brittle plastic ends
and they have to be soft plastic in the schools.

They replaced about 100 of them on the TV carts.

If you have to use a cord on your table saw, planer or
any larger shop equipment it needs to be 10 gauge.


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## AZ Termite (Dec 20, 2008)

Its good to hear you already got with the electrician. I just built a new shop last year and had an electrician come and wire everything. He gave me a hard time about how many boxes and outlets that I wanted and the size of the service, but I wanted to be able to run anything I wanted without using extension cord or having to worry about whether I had enough power. I have a 100A service that comes right from the meter box, I have 33 boxes, half of them are single gang and the other half are double gang. There are 9 of the singles that are 220v the rest are 110v. There are a total of 45 110v outlets. Just the materials cost me $1600, got the labor for free, my neighbor owed me a favor. In hind sight I may have gone a little overboard but I can tell you this, I haven't used an extension cord for anything to this point.


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## GeorgeC (Jul 30, 2008)

BHOFM said:


> Make sure you get "good" cords, 12 gauge even
> for the shop vac and such.
> 14 gauge is fine for sanders and drills and small
> tools as long as they are no too long.
> ...


Why? If you look at the electric codes for installed wiring you do not need that gauge for that current application.

G


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## AZ Termite (Dec 20, 2008)

George, The smaller the cord is and the longer it is the more power it loses. The wiring in your house/shop is a solid wire. The wire in an extension cord is braided, that is were the power loss comes from. The bigger the wire in the extension cord the less loss there is. The ideal all around cord is 12g 10'-15'. If you have a 14g or 16g cord 100' long I would not try to do very much with it. You may not see it right away but in time that small cord will eat your tools.


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## GeorgeC (Jul 30, 2008)

AZ Termite said:


> George, The smaller the cord is and the longer it is the more power it loses. The wiring in your house/shop is a solid wire. The wire in an extension cord is braided, that is were the power loss comes from. The bigger the wire in the extension cord the less loss there is. The ideal all around cord is 12g 10'-15'. If you have a 14g or 16g cord 100' long I would not try to do very much with it. You may not see it right away but in time that small cord will eat your tools.


I certainly agree that smaller gauge and longer equal power loss. However, there is a point of diminishing returns. For a 10' extension for most power hand tools 14 gauge is perfectly adequate. I want my 100 ft. long cords to be 12 gauge.

The amps running in the cord do not care if the wire is solid or braided. Extension cords have to flex, that is why braided wire is used. Fixed wire installations can use solid core as it does not move.

Have a good day.

George


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## AZ Termite (Dec 20, 2008)

George, I agree with you. Many people have no idea what a 14g cord 100' long will do to bigger tools. I work for an equipment rental company, I can't tell you the number of burnt wires and brushes I have replaced in hammer drills and electric jackhammers because the person that rented it used a small 100' cord to run it. I have 3 extension cords here at the house, two are 15' and one is 50' all are 12g and the only thing they are used for is small hand power tools ie.. drill, palm sander and the like.


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## BHOFM (Oct 14, 2008)

George;

My shop is all 10g. 

I think 12 should be minimum for shop wiring!

If you have a 14g service you don't need to plug any
kind of extension in it for any purpose.


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## Bigred15 (Dec 22, 2008)

Update:
I got a second opinion on the shop like I always do when getting stuff looked at. The second electrician said that there was now way that I could use the same wire that is leading from the house to the workshop for a 100 AMP breaker. It is a 6 AWG wire and he said that I need at least a #4, but at the distance I have to go (150 to 200 feet) it would be better to use a #2. The cost to replace this wire plus the $800 in work that I wanted accomplished is not feasible right now. So the electrician suggested an alternate solution to buy me time until I can afford to get all the work done at once. He suggested that I replace the two 30 amps with 20s, the 50 amp with a 30, and do away with the double pole 20 amp 220 circuit that is not being used. The will free up 2 slots in the breaker box. Then one 20 amp circuit would be installed and a second set of wall sockets will be run using 10 AWG wire. This second set of wall sockets would be for the big power tools like the table saw and such. This would allow me to run the shop vac and lights on a different circuit and not run the risk of over loading any of the wire. FYI the current wire in the shop is 12/2 AWG. Thoughts???


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## AZ Termite (Dec 20, 2008)

When I ran my wire from the meter to the shop the run was 147' I used 2- #2's and 1-#4. Just those three wires were the majority of the $1600 I spent on electrical, and I had no labor costs other than a case of beer for the neighbor. I used 12/2 for all my 110v runs. I used 10/2 for all my 220v runs. I used a 100amp box with 20 spaces and I only have two spaces left free.


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## WDChew (Aug 31, 2007)

He is right on the recommendation for the feed.
You don't have to have 10g for the shop internal wiring, since you will use 20a breakers (=12ga), but it certainly will give you some insurance using 10ga on 20a circuits. (you can always use larger wire on smaller breakers, just not the other way around.)


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## jraksdhs (Oct 19, 2008)

*I dont understand.....*

why in the world would you wire a whole shop in 10g?



BHOFM said:


> George;
> 
> My shop is all 10g.
> 
> ...


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## dollis (Dec 28, 2008)

6AWG under 100' is good for a MAX of 60Amps! He is VERY right not to use a 100 A breaker. The shop can have a panel with 150 Amps capacity though(7 breakers of 20Amps) just like a house breaker box is 3-4 times the 200Amp if all totaled. I would split the lights on its own breaker. The AC unit has a 50 "probably" for what is called FLA Full load Amps + 30% for start up current rounded up to next larger standard breaker size. If you don't have a use for the 240V circuit the scrap it and use the spaces. Lights + outlets on the same circuit is an accident waiting to happen. Would you want to use a skew in the dark? or have some one turn the lights off when your router is running? Lights go out instantly motors DONT stop instantly. I would RUN from the one that wants to install the 100A breaker. Get another electrician to look at your shop. Inform him that it is for a temporary ONLY if you are sure about the addition.


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