125A feeder to garage

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Old 09-27-20, 01:10 PM
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125A feeder to garage

I am running a 125A (1/1/1/6 copper) feed from the house to a new detached garage. 2” PVC conduit is in the ground already. Now I need to run the conduit into the garage, and also do the hookup at the house (which is much more complex).

First, punching the 2” conduit into the garage. My AHJ requires RMC elbows where the conduit comes up out of the ground, and RMC or IMC from the elbow to the LB. PVC/EMT are not allowed here. OK, but how do you hook all this up? Do you cut pieces of 2” RMC and thread them with a pipe threader? Or do you use compression fittings on the RMC? EMT compression fittings, I assume, will not meet code (and I’d think they would rust). But I could not find 2” “RMC compression” fittings at menards. The guy there said you have to thread RMC.

2nd – once you get through the wall, how do you get from there to the panel directly above? 2” EMT elbows are too wide… use an LB? seems like that would look goofy, but not sure what else to do.

3rd - the hookup at the house. For various reasons I do not want to run the 1Ga feeder from a breaker in the existing panel inside the house

. My plan is to add an external 200A main breaker panel on the outside of the house, and use that as the feeder point for both the garage (via a 125A breaker) and the house (via 200A feed-through lugs). I also want to add a generator ATS prior to the 200A outdoor panel, so the Meter would feed the ATS, which would then feed the 200A outdoor panel. Then the house & garage. I want to attach the ATS and 200A panel to the brick chimney next to the meter. See attached photo. The plan is to feed the 200A back to the meter, to use the existing 2” conduit to the panel inside the house.Ok – so many questions here…
- What’s the best way to run the feeders to/from the meter to the ATS and outdoor panel? 2” RMC? Or use Nema 3R wiring troughs? I have to route around 2 corners… an inside and outside 90.

- How far above ground do these outside runs need to be? Is there a code for this?

- If the various boxes have knockouts less than 2” that are “in the way”, what do you do? do you cut a 2” hole right over them? that doesn’t seem like it would work… but then how do you get a 2” hole where you want it?

I have more questions but need to get past these first so I can proceed with the project.



 
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Old 09-27-20, 02:06 PM
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On the pvc in the ground..... put on a 2" pvc female connector. The RMC 90 will screw in directly. Add a 2" metal coupling to the RMC 90. You can come up in a galvanized nipple to a threaded LB. Use a short nipple to go into the panel. You can get the galvanized pipe with the threaded ends from the home improvement store.

200A service ?

You would need to come out of the meter and feed the ATS first. Then back to the house panel. Not all ATS panels have dual output lugs. You'd need to check that to connect the new 200A panel to the ATS.
 
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Old 09-27-20, 02:28 PM
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ok. at the garage I'm going through the wall about 18" above grade (I have siding trim detail for this purpose). the panel will be normal height, so I can't just nipple into the panel from the LB - I have to go in and up and into the panel from below. I did it this way to avoid having an unsightly conduit run up the outside of the garage. the siding is done so its too late to change it now.

Yes, I suppose I could just use nipples to connect the RMC 90 to the LB... if I can get the right combination of lengths. I was thinking I'd cut down a piece of RMC and use a compression fitting down at the 90, if the compression fittings are rated for that.

Yes 200A service. The ATS will feed a single outdoor panel. That outdoor panel willl then feed the house and garage. The panel inside the house will then be a "sub-panel" technically. I know this will require moving the ground. the mechanics of hooking up all the conduit (or wiring troughs, if possible) are the current challenge. I'll obviously have to hire an electrician to do the final wiring cutover, but want to get everything else in place first.





 
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Old 09-28-20, 05:15 AM
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Hi, just curious as to where you plan on mounting all the equipment, certainly not at the current location with those condenser units sitting there.

Geo 🇺🇸
 

Last edited by Shadeladie; 10-02-20 at 07:55 AM.
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Old 09-28-20, 06:52 AM
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As far as I know it isn't allowed to use the meter box as a chase to feed wires back through. Unless it's a meter main with customer access.
 
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Old 09-28-20, 07:26 AM
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As far as I know it isn't allowed to use the meter box as a chase to feed wires back through. Unless it's a meter main with customer access.
yeah I would've thought so too, but when the inspector was here inspecting the conduit depth I talked to him about all this, and he was the one who suggested going back into the meter... he said to just cut a hole in the side and run the wires back in. he also didn't have a problem putting the new boxes on the chimney.

but I can't mount these boxes and finish the underground conduit until I know how i'm going to run the wires. the NEMA3R wiring troughs don't have the knockouts I need, and the knockout they do have are in the way of where I'd want to put 2" holes. doing all this in 2" RMC on the outside of the house seems like a bad idea and would look terrible. not really sure what to do next.
 
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Old 09-28-20, 10:21 AM
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Use hole punches were you need them, trying to avoid existing pre-punches. I did run into trouble punching 2" conduit into a busy area and had to use knockout reducers to clean it up.
 
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Old 09-29-20, 06:31 AM
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My power company (Dominion Energy) doesn't allow any other wiring to run through the meter enclosur. It isn't a local inspector's call.
 
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Old 09-29-20, 10:28 AM
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Or do you use compression fittings on the RMC? EMT compression fittings, I assume, will not meet code (and I’d think they would rust). But I could not find 2” “RMC compression” fittings at menards. The guy there said you have to thread RMC.
You can use compression couplings and connectors when you have no threads. No, not EMT compression fittings, but couplings and connectors for RMC. Use threaded nipples where ever possible. Don't forget to use bushings.
https://www.menards.com/main/electri...4430926930.htm

https://www.menards.com/main/electri...4430894454.htm
 
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Old 09-29-20, 11:12 AM
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forgive the ignorant question - but what are the bushings for? where do they get used?
 
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