Who knows electrical?
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From: Rockford, Illinois
Who knows garage wiring? Im wiring my garage and I have a few questions. First off I have 100amp service to the house. My garage is about 75 foot away from the panel in the house. Im pulling a 60 amp breaker in the house for the garage. Then im running (3) 4ga wires to the garage for 220 in an underground conduit.
1) Do I run a ground wire off the garage panel to a ground rod outside? If so what size should that wire be?
2)How many outlets can I safely put on a 20 amp breaker without tripping it all the time?
3)Do I make the first outlet in every circuit a GFI or does every outlet have to be a GFI
Thanks in advance,
Bryan
1) Do I run a ground wire off the garage panel to a ground rod outside? If so what size should that wire be?
2)How many outlets can I safely put on a 20 amp breaker without tripping it all the time?
3)Do I make the first outlet in every circuit a GFI or does every outlet have to be a GFI
Thanks in advance,
Bryan
Last edited by UA-Plumber; Oct 31, 2006 at 05:58 PM.
Originally Posted by UA-Plumber
Im wiring my garage and I have a few questions. First off I have 100amp service to the house. My garage is about 75 foot away from the panel in the house. Im pulling a 60 amp breaker in the house for the garage. Then im running (3) 4ga wires to the garage for 220 in an underground conduit.
1) Do I run a ground wire off the garage panel to a ground rod outside? If so what size should that wire be? Not sure, but run to a ground rod at the garage. Rule of thumb is, whatever ga. wire you bring in, run the same for a ground.
2)How many outlets can I safely put on a 20 amp breaker without tripping it all the time? Between 4 and 6 safely.
3)Do I make the first outlet in every circuit a GFI or does every outlet have to be a GFI The first one should sufice, but I like to do every other.
Thanks in advance,
Bryan
1) Do I run a ground wire off the garage panel to a ground rod outside? If so what size should that wire be? Not sure, but run to a ground rod at the garage. Rule of thumb is, whatever ga. wire you bring in, run the same for a ground.
2)How many outlets can I safely put on a 20 amp breaker without tripping it all the time? Between 4 and 6 safely.
3)Do I make the first outlet in every circuit a GFI or does every outlet have to be a GFI The first one should sufice, but I like to do every other.
Thanks in advance,
Bryan
Hope that helps.
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From: Not in Koonerville MD anymore
ok i have a few questions for you. you say you have a 100amp service for your house. and you are going to put 60amps on the garage. my question is how big of a house do you have? is the pannel/wiring new or old? are your appliaces gas or electric? what kind of heat do you have? the reason i ask this is because a normal house will require more than 40 amps to operate. not to say that you would ever pull 50amps in the garage but what if you did. then your going to be blowing breakers and mabey even a fire.
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From: Rockford, Illinois
Originally Posted by mwalls54
ok i have a few questions for you. you say you have a 100amp service for your house. and you are going to put 60amps on the garage. my question is how big of a house do you have? is the pannel/wiring new or old? are your appliaces gas or electric? what kind of heat do you have? the reason i ask this is because a normal house will require more than 40 amps to operate. not to say that you would ever pull 50amps in the garage but what if you did. then your going to be blowing breakers and mabey even a fire.
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I'm wiring my garage and I have a few questions. First off I have 100amp service to the house. My garage is about 75 foot away from the panel in the house. I'm pulling a 60 amp breaker in the house for the garage. Then I'm running (3) 4ga wires to the garage for 220 in an underground conduit. Be sure to use 1 white (or white tape to indicate the neutral) and 2 colored wires. Use 1 size heavier if using aluminum conductors. You might also want to pull a couple of #12 wires in the conduit for a 3 way light switch to turn on the lights from the house or garage.
1) Do I run a ground wire off the garage panel to a ground rod outside? If so what size should that wire be? Run a green or bare ground wire from a ground rod to the sub panel. Use a #4 copper wire for 100 amps.
2)How many outlets can I safely put on a 20 amp breaker without tripping it all the time? Only one outlet per breaker if you have something like an air compressor or heater that draws 15 amps or more. Plan ahead and have a separate circuit on each side of your workbench as well. I suggest no more than 6 outlets per breaker if they will only be used for lights, radio etc. Running more circuits with fewer outlets on each is always better than not enough circuits. You are not limited to only 3-20 amp breakers on your 60 amp main panel as you might think. Buy a sub panel with plenty of spaces and don't forget to allow for at least 4 spaces for a couple of 240 volt breakers (mig welder, air compressor, powder paint oven etc).
3)Do I make the first outlet in every circuit a GFI or does every outlet have to be a GFI? Just the first outlet on each circuit as long as you wire it for pass through protection to the other receptacles on that same circuit (use all 4 GFI terminals plus ground).
1) Do I run a ground wire off the garage panel to a ground rod outside? If so what size should that wire be? Run a green or bare ground wire from a ground rod to the sub panel. Use a #4 copper wire for 100 amps.
2)How many outlets can I safely put on a 20 amp breaker without tripping it all the time? Only one outlet per breaker if you have something like an air compressor or heater that draws 15 amps or more. Plan ahead and have a separate circuit on each side of your workbench as well. I suggest no more than 6 outlets per breaker if they will only be used for lights, radio etc. Running more circuits with fewer outlets on each is always better than not enough circuits. You are not limited to only 3-20 amp breakers on your 60 amp main panel as you might think. Buy a sub panel with plenty of spaces and don't forget to allow for at least 4 spaces for a couple of 240 volt breakers (mig welder, air compressor, powder paint oven etc).
3)Do I make the first outlet in every circuit a GFI or does every outlet have to be a GFI? Just the first outlet on each circuit as long as you wire it for pass through protection to the other receptacles on that same circuit (use all 4 GFI terminals plus ground).
Last edited by gto69judge; Dec 29, 2006 at 12:40 PM.
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if the garage is 75 feet you should pull a 10-3 home run (red for lights and black for tyhe plugs) and u can wire the rest of the garage with 12 gauge and not have to worry about any voltage drop.
you should (really really) run at least a 8 gauge ground to the panel.
code in the n.e.c. book is 10 outlets per circuit.10 lights per circuit.
only the home run for the plugs needs to be gfi, if any plug trips it will just trip the gfi(and u dont have to walk 75 feet to turn the breaker back on.
i've done close to 10 same size garages and no complaints(just make sure your panel can handle everything)i would use a sub panel
you should (really really) run at least a 8 gauge ground to the panel.
code in the n.e.c. book is 10 outlets per circuit.10 lights per circuit.
only the home run for the plugs needs to be gfi, if any plug trips it will just trip the gfi(and u dont have to walk 75 feet to turn the breaker back on.
i've done close to 10 same size garages and no complaints(just make sure your panel can handle everything)i would use a sub panel
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Originally Posted by 04gtoBMXracer
if the garage is 75 feet you should pull a 10-3 home run (red for lights and black for tyhe plugs) and u can wire the rest of the garage with 12 gauge and not have to worry about any voltage drop.
you should (really really) run at least a 8 gauge ground to the panel.
code in the n.e.c. book is 10 outlets per circuit.10 lights per circuit.
only the home run for the plugs needs to be gfi, if any plug trips it will just trip the gfi(and u dont have to walk 75 feet to turn the breaker back on.
i've done close to 10 same size garages and no complaints(just make sure your panel can handle everything)i would use a sub panel
you should (really really) run at least a 8 gauge ground to the panel.
code in the n.e.c. book is 10 outlets per circuit.10 lights per circuit.
only the home run for the plugs needs to be gfi, if any plug trips it will just trip the gfi(and u dont have to walk 75 feet to turn the breaker back on.
i've done close to 10 same size garages and no complaints(just make sure your panel can handle everything)i would use a sub panel
I agree that a sub panel is the best plan for your shop. Be sure NOT to connect the ground and neutral at your sub pannel. There is only one G-N connection allowed at the service entrance (your main pannel).
Some suggestions;
- Use 12 gauge wire for all your branch circuits.
- Install 2 gang boxes and put in 2 outlets each.
- Put the disconnect by the door. It's nice to turn all the shop off with a single switch. This eliminates the possibility of leaving something on and causing a fire.
sub panel is the only way to fly, I wouldnt use aluminum wire for anything. I know its cheaper, but i just wont use it ..period. I got a similar sized garage and I just installed a 100 amp subpanel with a 60 amp breaker. I wont pull any more juice than that. If i may recommend anything, I recommend you go square D. Some people may disagee, but I'm not a fan of cutler hammer. Do you live in a rural area? if not or maybe even if so, better check to make sure you dont have to get a permit, or have it inspected before you turn it on. That or make sure a city wig dont drive by and see you pulling wires in the conduit without a permit. I think #4 wire is going for like 2.00 a foot here or so.
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From: Rockford, Illinois
Originally Posted by redbandit98
sub panel is the only way to fly, I wouldnt use aluminum wire for anything. I know its cheaper, but i just wont use it ..period. I got a similar sized garage and I just installed a 100 amp subpanel with a 60 amp breaker. I wont pull any more juice than that. If i may recommend anything, I recommend you go square D. Some people may disagee, but I'm not a fan of cutler hammer. Do you live in a rural area? if not or maybe even if so, better check to make sure you dont have to get a permit, or have it inspected before you turn it on. That or make sure a city wig dont drive by and see you pulling wires in the conduit without a permit. I think #4 wire is going for like 2.00 a foot here or so.
Bryan
you dont really need a gfci in your garage. only outside or where water and weather excist. Most garages I see have the outlets 4ft off the ground. Every state is different though with codes.
Sub Panel The best bang for the buck is a Square D Homeline Value Pack, available at Lowes and Home Depot etc. It sells for $48 or so and has 20 spaces and a 100 amp main breaker. The value pack also includes 5-20 amp 120 volt breakers. Buy a 60 amp breaker for your house panel feeding the garage and the 100 amp breaker in the garage panel will act as a main shut off switch in the garage.
Last edited by gto69judge; Nov 26, 2006 at 01:15 PM.
I'm not NEC certified or anything like that (just done alot of work and have alot of hands on experience in the military) You need to consider upgrading the house circuit first and foremost. 100 amps is not enough. You should have a 200 amp panel for the main breaker panel in the house. You should run a 100 amp panel to your garage. That is a decent sized garage and do it right. You gotta figure on having a 50 amp draw on a 220 circuit IE plasma cutter. Do it right. Once you get the right sized main panel in the house then you can go from there. Yeah you can add a subpanel, but that isn't gonna get you the added amperage that you need.
Although kossuth makes a good suggestion about upgrading the home panel, in most cases it is not necessary. IF you actually manage to trip the house main breaker by using an abnormally high load in the garage, just back down on the home load during that time. By that I mean shut off the stove or A/C and electric water heater until you are done with the high demand in the garage.
If you anticipate a large garage draw (such as a 2 stage air compressor and large welder running simultaneously) you should run larger wire (such as #2 or better yet, #0 Aluminum) to the garage capable of supplying 100 amp service. That way, if you eventually upgrade your house panel, you can simply change out the 60 amp breaker for a 100 amp breaker.
Copper wire has doubled in price this summer so install a large conduit that will allow you to use the larger Aluminum wire instead of copper. Aluminum wire is used to feed your electric meter and probably your main panel and is fine for feeding your sub-panel. Use Copper wire for all your branch circuits inside your garage.
If you anticipate a large garage draw (such as a 2 stage air compressor and large welder running simultaneously) you should run larger wire (such as #2 or better yet, #0 Aluminum) to the garage capable of supplying 100 amp service. That way, if you eventually upgrade your house panel, you can simply change out the 60 amp breaker for a 100 amp breaker.
Copper wire has doubled in price this summer so install a large conduit that will allow you to use the larger Aluminum wire instead of copper. Aluminum wire is used to feed your electric meter and probably your main panel and is fine for feeding your sub-panel. Use Copper wire for all your branch circuits inside your garage.
Aluminum wire is the best to use for feeder circuits. The only thing you have to do with aluminum wire is use a paste on the connections so it does not get corroded over time. If this happens it will overheat or the connection may loosen, either of which could cause a fire.
If you are running 12 guage 20 amp circuits, you should use 20 amp rated outlets. They are stronger which is useful for a garage, but they also will not overheat if you pull more than 15 amps through the outlet. Since the breaker and wire will allow the full 20 amps to pass.
I have two sub-panels and a 100 amp circuit that goes to the attic for a heat pump electrical heat elements all using aluminum with no problems. Just don't forget the paste.
If the main panel has a ground, you can run a ground through the conduit which would carry the ground to your sub-panel. If the conduit is large enough, just get an aluminum feeder cable in #2 or #0 wire and it will have all the wires and ground wrap necessary to properly connect the two boxes.
Good luck with your project!
If you are running 12 guage 20 amp circuits, you should use 20 amp rated outlets. They are stronger which is useful for a garage, but they also will not overheat if you pull more than 15 amps through the outlet. Since the breaker and wire will allow the full 20 amps to pass.
I have two sub-panels and a 100 amp circuit that goes to the attic for a heat pump electrical heat elements all using aluminum with no problems. Just don't forget the paste.
If the main panel has a ground, you can run a ground through the conduit which would carry the ground to your sub-panel. If the conduit is large enough, just get an aluminum feeder cable in #2 or #0 wire and it will have all the wires and ground wrap necessary to properly connect the two boxes.
Good luck with your project!
Garage wiring Gee guys, I wish people wouldn't offer advise when they really don't know the rules.
First off, your garage will need a ground rod or concrete encased electrode-20' of rebar in the slab/footing is typical. Run a #4 cu. conductor from the sub's ground bar to this ground or encase 20' of #4 in the slab. The #4 cu.feeding your sub is good for 100 amps(depending on the insulation) so if you feel the need to up your house service to supply 100 amps to the shop later, you will be fine.
The NEC requires you to calculate each recp. at 180 volt amps (1.5 amps) and not exceed 80% of the overcurrant (breaker) device. If you are using # 12 this should work out to 10 recepticles per 20 amp breaker. This is the MAX number permitted but you should determine your loads and provide circuits as needed. A metal chop saw will draw 12+ amps so you would want it on its own circuit for instance.
Remember, you can only use one device at a time; welder, grinder, drill press, etc, with the added load of maybe your air compressor, lights and maybe a cooler of some kind. The 60 amps will go a long way in a moderate shop, especially if you are the only one using power tools there. If you properly size your overcurrant devices to your wire, you should have not worry of fire.
A GFCI installed in the first outlet of a circuit can be wired to GFCI all downstream outlets All 120 volt recepticles must be GFCI protected.
Most towns require permits and inspections and local ordinances may modify(or not even follow) the NEC so you need to check with your local Building Department.
BTW, I've been a member of the IBEW for 35 years, an electrical inspector for 17.
First off, your garage will need a ground rod or concrete encased electrode-20' of rebar in the slab/footing is typical. Run a #4 cu. conductor from the sub's ground bar to this ground or encase 20' of #4 in the slab. The #4 cu.feeding your sub is good for 100 amps(depending on the insulation) so if you feel the need to up your house service to supply 100 amps to the shop later, you will be fine.
The NEC requires you to calculate each recp. at 180 volt amps (1.5 amps) and not exceed 80% of the overcurrant (breaker) device. If you are using # 12 this should work out to 10 recepticles per 20 amp breaker. This is the MAX number permitted but you should determine your loads and provide circuits as needed. A metal chop saw will draw 12+ amps so you would want it on its own circuit for instance.
Remember, you can only use one device at a time; welder, grinder, drill press, etc, with the added load of maybe your air compressor, lights and maybe a cooler of some kind. The 60 amps will go a long way in a moderate shop, especially if you are the only one using power tools there. If you properly size your overcurrant devices to your wire, you should have not worry of fire.
A GFCI installed in the first outlet of a circuit can be wired to GFCI all downstream outlets All 120 volt recepticles must be GFCI protected.
Most towns require permits and inspections and local ordinances may modify(or not even follow) the NEC so you need to check with your local Building Department.
BTW, I've been a member of the IBEW for 35 years, an electrical inspector for 17.
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From: Michigan
Originally Posted by pwrtrip75
you dont really need a gfci in your garage. only outside or where water and weather excist. Most garages I see have the outlets 4ft off the ground. Every state is different though with codes.
