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Discussion Starter · #1 ·
I have an overhead service feeding a 200a main panel outside and am installing (via feed through lugs) a panel directly behind the wall inside. I was not going to bond the sub panel but am still curious that if it is technically a continuance of the outside "main" panel due to it being fed through.. wouldn't it still be considered part of the main service and require to be bonded? Or a sub panel that should not have a bond. What are your thoughts? I believe this is how mobile homes are set up so maybe someone with more experience in that field could help out.
 

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200A panel outside, having "feed-through" lugs @ bottom of panel buses...*This interior "sub-panel" is it "MLO" (main lugs only) or does SUB PNL have overcurrent protection (breaker)..

Edited.. Still early on West Coast, so reading this again. *Your post #4 infers the interior "Sub Panel" is in fact MOL..

The only overcurrent protection (OCP) provided is @ the 200A main.. *Correct (?)
 

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Inside is a sub panel. I’ll add this. The wires from the lugs outside are feeder conductors, not an extension of the outside panel’s buss.
I do agree w/ backstay.. This is a "feeder" to the interior sub-panel. *Are the feeder conductors enclosed in conduit, or enclosed in a cable assembly?

*Being a feeder, no bonding of grounded conductor @ Sub PnL is required..
 

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Discussion Starter · #9 ·
I do agree w/ backstay.. This is a "feeder" to the interior sub-panel. *Are the feeder conductors enclosed in conduit, or enclosed in a cable assembly?

*Being a feeder, no bonding of grounded conductor @ Sub PnL is required..
The interior sub panel will be fed through a ridgid conduit nipple between the panels (they are back to back) The Main panel has a 200a breaker and the sub panel is MLO. I appreciate the answers I will be adding a ground bar to the sub panel and running a 4th (ground) wire. Idk why I wasn't thinking of the sub as a "feeder" that makes total sense. I haven't worked as an electrician since 1998 .. so I have some studying up to do on new NEC requirements especially regarding grounds and bonding. Thx for the replies, they are much appreciated.
 

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The interior sub panel will be fed through a ridgid conduit nipple between the panels (they are back to back) The Main panel has a 200a breaker and the sub panel is MLO. I appreciate the answers I will be adding a ground bar to the sub panel and running a 4th (ground) wire. Idk why I wasn't thinking of the sub as a "feeder" that makes total sense. I haven't worked as an electrician since 1998 .. so I have some studying up to do on new NEC requirements especially regarding grounds and bonding. Thx for the replies, they are much appreciated.
Make sure you get a grounding bushing on that nipple.
 

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Discussion Starter · #11 ·
Make sure you get a grounding bushing on that nipple.
you read my mind.. I was just about to ask about that. I was noticing those during my research. I was under the impression that residential services didn't need the grounding bushing.. only 277/480 I'm guessing I need one from my meter base to the Main panel as well then, thx (y)
 

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The interior sub panel will be fed through a ridgid conduit nipple between the panels (they are back to back) The Main panel has a 200a breaker and the sub panel is MLO. I appreciate the answers I will be adding a ground bar to the sub panel and running a 4th (ground) wire. Idk why I wasn't thinking of the sub as a "feeder" that makes total sense. I haven't worked as an electrician since 1998 .. so I have some studying up to do on new NEC requirements especially regarding grounds and bonding. Thx for the replies, they are much appreciated.
worksonit.. I made my determination (wee hrs of the morning) using Chapter 2/ Article 240.21(B)(1) "The 10ft tap rule". (must be in raceway) *It has your particular installation covered.

*Your 200A main @ exterior PNL, tapping the feed-through lugs, w/ your MLO @ the Sub PnL..
 

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Why not just put a 2 pole 100 in the main panel and install everything like a traditional sub-panel? Then you could run smaller wire and not have to size it for the 200a main, unless you need the full 200a out of the sub.
 

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Discussion Starter · #14 ·
Why not just put a 2 pole 100 in the main panel and install everything like a traditional sub-panel? Then you could run smaller wire and not have to size it for the 200a main, unless you need the full 200a out of the sub.
I need all 8 spaces outside for "outside stuff" and I had leftover 4/0 and available feed through lugs so this was the direction my brain took me in :geek:.. that would work too though but I am running out of $$ after realizing I needed AFCI breakers inside and grounding bushings... I never realized how much stuff costed when the companies I worked for were buying everything :oops: lol
 

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Discussion Starter · #15 ·
I sure do miss having a service truck full of stuff, access to bucket trucks and trenchers and "leftover" spools of wire. :sneaky:
 

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I need all 8 spaces outside for "outside stuff" and I had leftover 4/0 and available feed through lugs so this was the direction my brain took me in :geek:.. that would work too though but I am running out of $$ after realizing I needed AFCI breakers inside and grounding bushings... I never realized how much stuff costed when the companies I worked for were buying everything :oops: lol
Oh that makes sense, I didn’t realize you’re working with only 8 ckts in the main panel. I’ve never really been in a situation or have seen feed through lugs in a residential panel in my area so my mind just went to 2 pole breaker for sub panel.
 

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It’s good to take advantage of the feed through lugs. What’s the biggest breaker you can put in the meter/combo? You might not have been able to have a 200A inside without using the feed through lugs? I know square D make a 150A that takes four spaces and has the lugs on an angle. Big bucks and barely fits in their meter/combos.

As for the bonding locknut/bushing, I don’t think it’s required. It is a feeder at this point right?
 

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It’s good to take advantage of the feed through lugs. What’s the biggest breaker you can put in the meter/combo? You might not have been able to have a 200A inside without using the feed through lugs? I know square D make a 150A that takes four spaces and has the lugs on an angle. Big bucks and barely fits in their meter/combos.

As for the bonding locknut/bushing, I don’t think it’s required. It is a feeder at this point right?
Square D also makes a 200A breaker: QO2200
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$260.00 at my supplier, don't know if that's reasonable or not.

They also make a 225A sub-feed kit: QO2225SL

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That puppy will set you back about $380.00 at my supplier. Now that seems a little steep.....
 
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I’m surprised that a 200 would be allowed in a 200A panel. I know in the past we put in 225A panels, if we needed to feed out with a 200A?
 

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Discussion Starter · #20 · (Edited)
It’s good to take advantage of the feed through lugs. What’s the biggest breaker you can put in the meter/combo? You might not have been able to have a 200A inside without using the feed through lugs? I know square D make a 150A that takes four spaces and has the lugs on an angle. Big bucks and barely fits in their meter/combos.

As for the bonding locknut/bushing, I don’t think it’s required. It is a feeder at this point right?
It's an Eaton BRP08B200RF Main panel feeding another Eaton BRP20L200 sub panel. This is the first time i've ventured away from sqare d products and I've gotta say I'm not impressed... the way the breakers attach seem ok but the way the buss bars and neutral bars are mounted seems really subpar. And yes I believe it is considered a "feeder" as backstay and Dell have commented and should fall under 240.21(B)(1) as an "under 10ft" feeder tap but I'm still not clear as to weather or not that means it needs the grounding bushing or not. I'm assuming it does since I am using a 2" rigid nipple between the panels.
 
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