Need Help Feeding New subpanel

[exranger06]

I'm installing a 90 amp subpanel in my attached garage. I'm not sure what the best way to get the wire from the main panel to the subpanel is. I have attached pictures to show where the wire needs to go. I was planning on using 2-2-2-4 SER Al, unless someone has another suggestion for wire. The main panel is located in my finished basement, right next to a hearth for a wood stove:

I may or may not actually install a wood stove in the future. As far as I can tell, there has never been a wood stove installed since the house was new, even though the hearth is there. The other side of this wall behind the main panel and the hearth is the exterior of the house obviously, but to the left of the hearth, on the other side of the wall is the garage. So to get the wire into the garage, I would need to run the wire inside the wall to the left, behind the hearth, then through the wall into the garage.

This is the other side of the wall. The main panel is of course right behind the meter on the other side of the wall, and you can see the unfinished wood stove pipe coming through the wall. The adjacent wall where the AC condenser is mounted is the side of the garage.




And this is inside the garage. On the other side of the finished wall is the basement, and the unfinished wall is the exterior wall where the AC condenser is right on the other side.


I would like to mount the subpanel right in this corner on the unfinished wall.

What would be the best or easiest way to get the wire into the garage? Should I try to go behind the hearth? What's the minimum distance the wire has to be from the chimney? Or should I just run a conduit on the outside of the house and through the side wall of the garage, since it's a short run anyway?

 

[OccupantRJ]

I would go outside. You already have a lot of utility in that area anyway.

 

[walrus]

I would go outside. You already have a lot of utility in that area anyway.

Looks like the lower right of that panel is ripe to go right out the back. The only issue is whats in the way to get to garage. Might have to go over other stuff out there.

 

[exranger06]

I just realized if I run conduit on the outside of the house, it's a wet location meaning SER cannot be used, correct? What type of wire should I use instead?

 

[pattenp]

SER can be used in wet above ground locations.

 

[wyliesdiesels]

Come out below the meter and bring it around the wall right next to the mini split.

 

[sands35]

Looks like there are already 2 other smaller conduits coming through the wall.

Those will give you a reference so you know where the hole saw will come through the wall. I'd do an LB PVC into conduit around the corner to another LB into the new sub-panel. You may want to run it down to the concrete and under the condenser unit and go through the wall to the right of the condenser. That way you won't overlap conduits. That would be 3 90* elbows. 1 1/4 PVC will work on the fill tables, but 1.5" or 2" would be much simpler to pull.

Also need a flashing kick-out on the roof. Left side of the gutter just under the AC conduit.

 

[exranger06]

Ok so I decided I'm running 1.5" rigid steel conduit outside. I'm a little confused on how to get the conduit out the back of the panel and through the wall. I'm thinking of buying one of these to connect the conduit to the panel:http://m.homedepot.com/p/Halex-1-1-2-in-Rigid-Water-Tight-Conduit-Hub-16315/100118103
But I'm wondering how I'm going to get that connector through the wall with that big flange on it. Do I drill a large hole on the exterior wall and just caulk around it when I'm done? Or should I just forget about that connector, run a threaded conduit through the wall and just stick a locknut on the end inside the panel? Or do something else?

 

[ezzzzzzz]

I'd pull back the wires feeding the a/c and whatever circuit runs around that corner. Cut the PVC on both of those runs where it runs straight. Remove the existing outside box and install a larger one to accommodate the original wires and the feed for the subpanel. You may have to open the hole going into the main panel too. Rerun the PVC for the original runs and a larger PVC run straight down the wall and into the garage. You'll probably need a disconnect outside between the pull box and the subpanel to be legal. The subpanel can be installed so the wiring runs right into it.

 

[wyliesdiesels]

I'd pull back the wires feeding the a/c and whatever circuit runs around that corner. Cut the PVC on both of those runs where it runs straight. Remove the existing outside box and install a larger one to accommodate the original wires and the feed for the subpanel. You may have to open the hole going into the main panel too. Rerun the PVC for the original runs and a larger PVC run straight down the wall and into the garage. You'll probably need a disconnect outside between the pull box and the subpanel to be legal. The subpanel can be installed so the wiring runs right into it.

That may not work due to the requirement of derating multiple conductors in the same pipe.

 

[ezzzzzzz]

That may not work due to the requirement of derating multiple conductors in the same pipe.

If so, he could install a box specific for the feed where that original box resides. The other two runs could be joined with another pull box straight into the main panel just to the right of the existing hole. There's plenty of room in the lower right corner of the main panel next to that single 120V feed.

 

[exranger06]

Whether or not I relocate or replace the existing box, I still need to figure out how to connect 1.5" conduit to the back of the main panel. Anyone have some advice on that?

 

[exranger06]

I just got an idea: What if I cut a little bit of drywall out to the left of the panel and use a knockout on the left side of the panel. I can use an LB to make a tight 90 degree turn and go right out the wall. I know the LB has to remain accessible and I can't drywall back over it. I can maybe get some kind of access panel for it. Thoughts?

 

[ezzzzzzz]

Why not enter directly into the box? You'll only need to drill a hole large enough to fit the 1.5 " pipe. A short piece of that pipe, threaded on both ends, can be fitted through and secured using appropriate nuts on the main panel and pull box sides.

 

[exranger06]

That was basically the original plan, except I for some reason thought that I needed a connector like the one I linked to above at the panel. If I used that, I would've had to drill a larger hole on the outside to get the connector through and I would've had a gap all around the conduit. But since I now realize I don't need the connector, I can do it like you said. I assume that I can use an LB on the outside instead of a nut?

 

[walrus]

That was basically the original plan, except I for some reason thought that I needed a connector like the one I linked to above at the panel. If I used that, I would've had to drill a larger hole on the outside to get the connector through and I would've had a gap all around the conduit. But since I now realize I don't need the connector, I can do it like you said. I assume that I can use an LB on the outside instead of a nut?

If you are going to use rigid(why you want rigid is beyond me but...) a rigid ****** with a lock nut screwed all the way on so that it rests against the back of the panel, threads stick into the panel another lock nut and a plastic bushing.

 

[exranger06]

So you're saying I should have two locknuts sandwiching the panel? That brings me back to my first dilemma of drilling a bigger hole and having a gap around the conduit. ..

 

[FordTruckWench]

So you're saying I should have two locknuts sandwiching the panel? That brings me back to my first dilemma of drilling a bigger hole and having a gap around the conduit. ..

Locknuts aren't all that big. The hole would only need to be a little bigger. Or, can you drop the lock nut behind the panel on a string and then thread it onto the rigid conduit?

Um, scratch that.

An LB has a projection on the back. You need to drill a hole bigger than the pipe anyway. A locknut easily fits in this hole.

 

[walrus]

So you're saying I should have two locknuts sandwiching the panel? That brings me back to my first dilemma of drilling a bigger hole and having a gap around the conduit. ..

yes, caulk is your friend

 

[exranger06]

Ok, so I think I got the connection to the panel figured out. I should know for sure tonight when I finish drilling the hole. I have another (possibly stupid) question. It's kind of hard to see in the picture, but there's a conduit coming out the bottom of the meter box for the ground wire. It's either 3/8" or 1/2" conduit. The new conduit I'm installing needs to go horizontally right over that conduit. Is it OK and within code to have a conduit go right over another conduit?

 

[FordTruckWench]

The new conduit I'm installing needs to go horizontally right over that conduit. Is it OK and within code to have a conduit go right over another conduit?

Yes conduit can cross. Pros would bend a little hump in one of them so both run against the wall as much as possible. I however don't know the requirements for that.

Realize you have other stuff to avoid: The conduit to the A/C, and the A/C lines.

It might be easier to have the "ground" conduit run on top with your new conduit under it.

 

[exranger06]

I thought about the AC stuff. I think my plan is to use a couple of 90 degree sweeps to go up and over the existing conduit box, run above the existing conduit, and go through the garage wall in the corner, right below the white AC lines. That should put it right about where the panel will go. Might need another LB on the other side to go one more stud cavity over and 90 degree sweep right into the bottom of the panel.

 

[exranger06]

Success! I know I need a bushing on the end inside the panel, and I need to remount the cable TV amplifier, but those will wait until the conduit is all done. I also removed that telephone box that was beneath the meter, since I don't have a landline and probably never will. Time to start cutting some pipe!

 

[wyliesdiesels]

What type of Cutler hammer panel is that- BR or CH? Looks likea BR what with the AL bus bar but it has the CH paint color.

 

[pattenp]

What type of Cutler hammer panel is that- BR or CH? Looks likea BR what with the AL bus bar but it has the CH paint color.

I believe it's a CH because of the breaker handle color. The buss bar is tin plated so it's not copper color if that's what you are thinking by saying it's aluminum.

 

[wyliesdiesels]

I thought the same but Ive never seen a tin plated CH. All the CHs I've worked on were copper bussed.

 

[exranger06]

It's a CH panel. I bought a 100 amp CH Eaton subpanel for the garage. I got an awesome cyber Monday deal. It included a 30 amp double pole breaker and five 20 amp single pole breakers, also already has a ground bar installed. Only cost $41.22 including tax.

 

[pattenp]

I thought the same but Ive never seen a tin plated CH. All the CHs I've worked on were copper bussed.

Well.. I said tin plated for a lack of actually knowing what the copper bus is plated with. Here's what the CH panel description says....."silver flash plated copper bus".



*

 

[wyliesdiesels]

I have a CH in my house and its copper with no plating.

 

[exranger06]

My new CH subpanel is copper with no plating but the main panel is also a CH panel. It even has a sticker on the inside saying to use CH breakers. The house was built in 1979.

 

[wyliesdiesels]

Interesting.

Well regardless, theyre good panels so u should be stoked to have them.

 

[CNGsaves]

OP . . nice score on the CyberMonday deal for panel and breakers for $42 . !!

While you're cleaning up wiring on outside of house, you might consider relocating the "Home Run" location for all those RG6 cableTV cables . . . like in basement or unfinished space. Re-route runs so that they are IN-WALL in house instead of strung around exterior of house.

I've got a cluster-fawk of CATV wires on house I bought as looked like they let a stone-cold drunk from the cable company to string wires all over every gutter on the house !!

 

[pattenp]

My new CH subpanel is copper with no plating but the main panel is also a CH panel. It even has a sticker on the inside saying to use CH breakers. The house was built in 1979.

I have 2 CH panels in my house, a 200A 42 space and a 100A 20 space. The main 200A panel has bus bars with no plating, but the bolt on breaker stabs are plated and are silver colored. The 100A main lug panel has bus bars with integrated breaker stabs that are all copper with no plating at all.

 

[exranger06]

Making progress...

 

[wyliesdiesels]

Looking good.

Looks like youre using one of the neutral bars as the EGC bar...

 

[exranger06]

Looking good.

Looks like youre using one of the neutral bars as the EGC bar...

Yeah, this panel came with two neutral/ground bars so I didn't have to buy a ground bar kit. The bar on the left is the ground bar, since it has a non-removable strap that bonds to the case of the panel. The bar on the right is the neutral bar. It had a small removable strap that bonds it to the case as well, which I removed.