Time to install subpanel

[Joel 67]

Guys,

It is time to install the 100A subpanel in my attached garage. Please spit ball this plan and let me know if I am off in any way.

My plan is to run #2 THHN for the two hots and neutral in a 1.5" conduit out to the garage using a #4 copper ground.

I have a few hundred dollars in Home Depot gift cards so I plan on getting the conduit, panel, etc from there. For anyone who is familiar with the inventory in HD's electrical dept, which panel should I try to get? They have a couple of 100A panels to choose from. Once the panel is installed I plan on running circuits for a dozen or so 110v outlets, a 220v compressor, a nat gas heater, and some lighting circuits.

thanks!

 

[mrb]

get a big enough panel, where you have room to add breakers later without having to resort to tandems. You can use a 200 amp panel if you want...

I think you can use #6 for the ground, im sure somone else will chime in on this.

 

[Joel 67]

Thanks, I agree I will get the biggest panel that I can within reason.

Can I use a 1.25" conduit? The run will be around 35" with two 90* turns.

 

[Gary S]

Jump the conduit up to 2". You will be glad you did when it comes time to pull the wire. Anytime you fill a conduit to the max allowed by the code, you get to sweat more getting the wires in there. I ran #2 wire to my garage and I used 2" conduit. I won't ever regret the few extra pennies it cost for the larger conduit.

 

[Aceman]

I don't understand you guys wanting to run conduit to attached garages. That's why they make cable. I'd run #2 AL SER and breaker it at 80 amps in the main panel. It'll be far cheaper and easier for you to run. For the limited loads in your garage it doesn't sound like you'll need the full 100 amps anyway.

 

[porschedude996TT]

Guys,

It is time to install the 100A subpanel in my attached garage. Please spit ball this plan and let me know if I am off in any way.

My plan is to run #2 THHN for the two hots and neutral in a 1.5" conduit out to the garage using a #4 copper ground.

I have a few hundred dollars in Home Depot gift cards so I plan on getting the conduit, panel, etc from there. For anyone who is familiar with the inventory in HD's electrical dept, which panel should I try to get? They have a couple of 100A panels to choose from. Once the panel is installed I plan on running circuits for a dozen or so 110v outlets, a 220v compressor, a nat gas heater, and some lighting circuits.

thanks!

You are doing what I did, #2 THHN and a #4 Bare Copper ground. When I installed I also had a UFER Ground in my foundation. I didn't tie the ground and the neutral in the subpanel as required by code. I'm guessing you should not install the green tie screw. I choose a panel that was the same as my main so that I could use the same breakers.

 

[WinFred]

Guys,

It is time to install the 100A subpanel in my attached garage.

My plan is to run #2 THHN for the two hots and neutral in a 1.5" conduit out to the garage using a #4 copper ground.



thanks!

up that to a 150 or 200 amp panel and you you'll have room to grow.... but you can't exceed the rating of your primary panel... if the primary is a 100 that's the maxon the sub panel and so on... unles you up grade the primary feeders all the way to the weather head...

how do you plan to tap off of the main panel???

you also need to run a 4th wire for a ground connection from panel to panel for a floating ground in the sub-panel... AND a ground (at least a #6) from the sub panel to earth.. (ground rod)
HD carries the QO series from Square D.. don't wast yur money on the Home lite panels...
if you can get a Siemens you'll do well... they have copper busses instead of the cheaper plated ones that are in Ge and Square D...
Siemens busses are reparable as where GE, Square D aren't...

Lowes carries Siemens.. see if you can spend the gift cards there.. also Lowes carries better grades of wire and cable for th same $$$...

 

[mrb]

up that to a 150 or 200 amp panel and you you'll have room to grow.... but you can't exceed the rating of your primary panel... if the primary is a 100 that's the maxon the sub panel and so on... unles you up grade the primary feeders all the way to the weather head...

how do you plan to tap off of the main panel???

you also need to run a 4th wire for a ground connection from panel to panel for a floating ground in the sub-panel... AND a ground (at least a #6) from the sub panel to earth.. (ground rod)
HD carries the QO series from Square D.. don't wast yur money on the Home lite panels...
if you can get a Siemens you'll do well... they have copper busses instead of the cheaper plated ones that are in Ge and Square D...
Siemens busses are reparable as where GE, Square D aren't...

Lowes carries Siemens.. see if you can spend the gift cards there.. also Lowes carries better grades of wire and cable for th same $$$...

his garage is attached, so there would be no additional grounding electrode for the subpanel.

floating ground?

 

[autowerks9]

I used 2-2-2-4 Supply cable in a 2" in conduit for my garage 100a panel. 80 amp braker at the main.

+1 for the larger conduit ( may want to add another 1.5 along side for cable/cat5/ telephone)

+1 Allow for added future circuts

..#4 wire to bond the main and sub panels. Must also add a ground wire to exterior ground rod for new panel.

 

[WinFred]

his garage is attached, so there would be no additional grounding electrode for the subpanel.

floating ground?

explain what you mean by "no additional grounding electrode" if ya would please...


Floating ground... field referrence to a seperate ground buss in the subpanel...
the subpanel has to have a ground buss and a buss for the nuetrals independent of each other...
the grounding buss has to also be connected to a ground rod independent of the house's main panel...

 

[WinFred]

side note....

100 amp panel using THHN/THWN stranded SE... good for 115 amps BTW....

L1 #2 black
L2 #2 tagged red... (comes in handy with keeping track of phaselegs if any controls have to be co or split phased with a motor on a piece of shop gear/equipment)... simpifies balancing the panel also...
C1 #2 tagged white... (nuetral)...
G1 #4 tagged green.. (ground)...
G2 #6 (minimum) tagged green or BC... stranded is better than solid... this conductor is bonded at the sub-panel ground buss and goes to an exterior ground rod... some AHJ's require ground rods to be done in pairs... the sub-panel's ground buss is also bonded to the panel's can...

 

[tfi racing]

I don't understand you guys wanting to run conduit to attached garages. That's why they make cable.

Exactly what I was thinking.Why go through all that extra work when a simple cable is more than adequate and more importantly quicker and easier so one can move on to better things like using that newly installed power.

 

[mrb]

explain what you mean by "no additional grounding electrode" if ya would please...


Floating ground... field referrence to a seperate ground buss in the subpanel...
the subpanel has to have a ground buss and a buss for the nuetrals independent of each other...
the grounding buss has to also be connected to a ground rod independent of the house's main panel...

a ground rod is one type of grounding electrode.
yes, the neutral bus has to be isolated from ground except for wherever the main bonding jumper is.

This is an attached garage. You would not install a ground rod for the sub panel in this case.

 

[WinFred]

This is an attached garage. You would not install a ground rod for the sub panel in this case.

this is another panel... it gets a rod....

local may have something to do with this and the AHJ.....

 

[WinFred]

Exactly what I was thinking.Why go through all that extra work when a simple cable is more than adequate and more importantly quicker and easier so one can move on to better things like using that newly installed power.

will it be mechanicly protected and meet clearences???

 

[WinFred]

and has the issue of main lug or main breakered panel been addressed???

 

[noslo04]

Currently in the process of adding a 100A subpanel in my attached garage also. I'm using 1-1-1-2 AL SE for the feeder, per the inspector. 2-2-2-4 CU would also work (at 4x the cost!). Last night, I bought a 100A main lug panel, but it will be exchanged for a 100A main breaker panel. Either one would meet code, but having a main breaker in the garage that would kill all power at once is an added benefit. The main distribution panel is in the basement, so the main breaker subpanel could prevent me from making a trip downstairs.

Bought a lot of my supplies this weekend using HD gift cards too.

 

[Aceman]

and has the issue of main lug or main breakered panel been addressed???

Winfred, what's your deal? You've popped into this thread a couple times now spouting off about ground rods and isolated ground busses and now you're worried about main breaker or main lug. Guess what? The NEC doesn't require a grounding electrode at a panel in an attached garage. Period. Why don't you start posting some code references before you start shooting from the hip?

It also does not care if you use a main breaker or main lug panel in an attached garage.

There may be local amendments, it's easy enough to call the building department and confirm.

 

[hidollartoys]

Also I dont think he is burying the conduit. Looks like a simple sub-panel in an ATTACHED space.

 

[neverenoughtools]

I used the Siemens panel on my upgrade

 

[mrb]

this is another panel... it gets a rod....

local may have something to do with this and the AHJ.....

um no it doesnt. Code section? Where are you located? I have never heard of any local ammendments anywhere which require a grounding electrode at a subpanel thats not in a detached structure.

 

[Big N8]

I agree with some of the other postings here. Run cable not conduit and run the largest panel you can. That way you have room to grow.

 

[WinFred]

There may be local amendments

there are...
I tend to follow them.. think them too...

 

[mrb]

There may be local amendments

there are...
I tend to follow them.. think them too...

where are you located? I would like to see this ammendment requiring a grounding electrode for a subpanel thats not in a detached structure.

Also, to offer general advice based on an arcane local requirement your jurisdiction has is a disservice to the OP, were he to follow it he would spend both time and money unnecessarily.

 

[Joel 67]

Thanks for the replies everyone. Just for clarification, I plan on a main breaker panel.

I wish I could run cable but local code requires all wires in conduit, but does not require a separate ground for an attached structure.

 

[WinFred]

where are you located?

.

Lake, Teller and Chaffee counties CO...


Also, to offer general advice based on an arcane local requirement your jurisdiction has is a disservice to the OP, were he to follow it he would spend both time and money unnecessarily.

you have no idea the "arcane" requirements...

 

[mrb]

Lake, Teller and Chaffee counties CO...


Also, to offer general advice based on an arcane local requirement your jurisdiction has is a disservice to the OP, were he to follow it he would spend both time and money unnecessarily.

you have no idea the "arcane" requirements...

where are these ammendments? Lake county adoped the NEC with no ammendments I could find. Teller and Chaffee county adopted the NEC and have minimal ammendments (prohibiting reduced neutral on residential services, commercial service over 200 amps requires plans stamped by state lic engineer, things like that.) Nothing about a subpanel in the same structure as the service requiring a seperate grounding electrode.

 

[WinFred]

do you remember the disconnects with single Buss style fues and spst toggle...

bet you won't find admendments for them either but they still have to be installed directly on airhandlers..
or grief you get installing a NG horizonatal unit in a crawl space... more you won't find...

 

[mrb]

do remember the disconnects with single Buss style fues and spst toggle...

bet you wont admendments for them either but they still have to be installed directly on airhandlers..
or grief you get installing a NG horizonatal unit in a crawl space... more you won't find...

I didnt look at the mechanical codes, only electrical. Those items you mentioned would be addressed by mechanical codes I would think.

 

[Joel 67]

Another question--home depot only has black #2 thhn. The guy there said it is common to use the black and mark it as white or red for the neutral and other hot. Is this a generally accepted practice or should I try to get other colors somewhere else?

 

[WinFred]

the diconnect is under electrical in Lake and mechanical in Park...

oh yeah... Park and Lake require a bond conductor to the rebar in the footers rom the meter can in new construction....

 

[WinFred]

accepted practice...
wrap the end with appropraitely colored tape for at least 6"... more is better...
the tape is also referred to as phase tape in some places...

 

[mrb]

oh yeah... Park and Lake require a bond conductor to the rebar in the footers rom the meter can in new construction....

thats required everywhere. Its called a ufer ground.

 

[Aceman]

Another question--home depot only has black #2 thhn. The guy there said it is common to use the black and mark it as white or red for the neutral and other hot. Is this a generally accepted practice or should I try to get other colors somewhere else?

You're fine. For a 100 amp panel a #8 green is sufficient also, you don't need #4.

 

[Aceman]

Another question--home depot only has black #2 thhn. The guy there said it is common to use the black and mark it as white or red for the neutral and other hot. Is this a generally accepted practice or should I try to get other colors somewhere else?

You're fine. For a 100 amp panel a #8 ground is sufficient also, you don't need #4.

 

[Charles (in GA)]

There's an echo in here

Charles

 

[Aceman]

DOH!

I guess anything worth saying is worth saying twice.

 

[Charles (in GA)]

Thats OK, just took advantage of the situation to have a little fun.

Charles