I need suggestions for a gnarly panel change job.

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Coppersmith

Coppersmith

Senior Member
Location
Tampa, FL, USA
Occupation
Electrical Contractor
I have a potential client who has a exterior FPE panel in the interior (toward the center) of his house he would like to replace. There is not enough attic space to get above the panel and no crawl space below it. He wanted it totally removed and everything wired to a new panel outside. There is already a small panel outside feeding this one (with a 1.25" rigid conduit) as well as some other circuits. I can only assume the FPE panel was originally outside and an addition was built around it.

I told him that totally deleting the panel would be very expensive since all the home runs would have to be re-run and no attic space mean ripping up the ceiling. I suggested making it a junction box and running all the branch wiring through the feeder conduit (after ripping out the feeder) to the new bigger outside panel.

Now reality is setting in. I have 32 CCC's in the panel which means derating to .45. Upsizing the wires would cause conduit fill to be exceeded. Adding more conduit runs will require tearing up the ceiling or a wall or the floor. I might be able to retrofit the FPE box and keep it as a panel, but I didn't take the dimensions so I'm not sure.

Anybody have any suggestions?

P.S. They have a nice floor to ceiling wooden cabinet built around the inside panel so ripping it out would be difficult.
 
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What's the floor s.o.g. or sleepers?
Can you put your head into the attic and look around?
What is the outside of the house by panel? Add new pipe run from outside in.
Sounds like ceiling repair to me, ring out every ckt. find nearest to fish to. I know you know this already.
 
LarryFine said:
Can you reduce the count by combining circuits into as many MWBCs as possible?
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That length extension of the existing branch circuits surely exceeds six feet so you'll be obligated to install AFCIs per 210.12(A) unless local ordinance excuses it. Selecting a new GE panel specifically for the single pole AFCI use on multiwires (with handle ties) will help with Larry's suggestion.
 
I thought the six-foot circuit extension applies to the load end of the circuit, not the supply end.
 
My last house had a 4/12 pitch roof (low) and there was enough room in the center to sit indian-style anyway.

The least expensive option would be to replace the panel in place and modify the cabinet around it as least destructively as possible.

If you truly have no attic access, no crawl space access, and he wants it somewhere else, throw him a high number, and enjoy tearing the heck out of them ceilings, to be repaired by someone else of course...

Even if all 32 ccc's were 120 volt circuits, and you could combine them all into multiwire Branch circuits, you're still looking at 16 ccc's minimum and some pretty nasty (50 percent iirc) derating.

But following up with Larry's excellent idea, there may be some circuits you could delete or combine to get your conduit fill and or derating in check.

Eta: al, Va still only requires afci Breakers on circuits serving bedroom Outlets. Yes, the original poster is in Florida, and it would be a concern for him, but not a concern for us.
 
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LarryFine said:
I thought the six-foot circuit extension applies to the load end of the circuit, not the supply end.
Click to expand...
In 2014 NEC the six foot language was in 210.12(B) Exception, and in the 2017 NEC the Exception is in 210.12(D).

However, in the 2017 new language was added to 406.4(D)(4) stating the 210.12(D) Exception could not be used for Replacements.

So, no, it is as Dennis Alwon intended in his original proposal, meant to apply to panel changeouts.
 
LarryFine said:
Can you reduce the count by combining circuits into as many MWBCs as possible?
Click to expand...

I was thinking I could not do that since AFCIs were now coming into play.

al hildenbrand said:
That length extension of the existing branch circuits surely exceeds six feet so you'll be obligated to install AFCIs per 210.12(A) unless local ordinance excuses it. Selecting a new GE panel specifically for the single pole AFCI use on multiwires (with handle ties) will help with Larry's suggestion.
Click to expand...

Yes, all the 120v circuits will now have to be AFCI since the extension will be 30-40 feet. I did not know GE had a method to AFCI MWBCs. I'd consider doing that, but a really hate GE products.

JFletcher said:
If you truly have no attic access, no crawl space access, and he wants it somewhere else, throw him a high number, and enjoy tearing the heck out of them ceilings, to be repaired by someone else of course...
Click to expand...

I laid in bed thinking about this job before I fell asleep and woke up thinking about it. I think you may be right.

I had already decided to give him a high number because this job will be a bear. I'm going to ditch the idea of using the existing conduit and instead I'm going to cut a channel in the ceiling from above the inside panel to above the outside panel. I'll set a large j-box flush in the ceiling and pull all the cables up from the inside panel into the new j-box. I'll run a UF cable for each circuit from the outside panel to the new j-box. Someone else can patch the drywall.

This deletes the old panel and eliminates the derating and conduit fill issues. I just have to convince the homeowner to allow me to tear up the ceiling a bit and to live with a j-box in the ceiling.
 
Coppersmith said:
Yes, all the 120v circuits will now have to be AFCI since the extension will be 30-40 feet. I did not know GE had a method to AFCI MWBCs. I'd consider doing that, but a really hate GE products.
Click to expand...
For decades, I stayed away from this line of products, as well. . . When I apprenticed, my old Master / Elec Contractor almost always installed GE and I had enough experience with it to happily commit to other brands.

However, with the advent of their AFCI combination-type breaker, which is PURE AFCI, meaning, there is zero ground fault sensing in the breaker (unless it is a Dual Function GFCI / AFCI), I had to re-evaluate my stance.

The problem of placing AFCI on an existing dwelling's existing branch circuits is the possibility of wiring mistakes that have collected in the Premises Wiring (System). Cross neutraling and accidental neutral-ground connections will play havoc with all the other manufacturer's AFCIs because of their ground fault detection. That leads to un-quantifiable troubleshooting that may, or may not, be required.

Having faced this myself, I have chosen not to have to explain the possible need to "go hunting" in the undisturbed wiring of the homeowner's dwelling, and, rather, explain that I am offering the most stable of the new safety AFCI overcurrent protective devices.

For adding AFCI to undisturbed existing branch circuits, I don't think there is a better solution. Just my opinion.
 
Coppersmith said:
I had already decided to give him a high number because this job will be a bear.
I'm going to ditch the idea of using the existing conduit and instead I'm going to cut a channel in the ceiling from above the inside panel to above the outside panel.
I'll set a large j-box flush in the ceiling and pull all the cables up from the inside panel into the new j-box.
I'll run a UF cable for each circuit from the outside panel to the new j-box.

Someone else can patch the drywall.
Click to expand...

you have a clear grasp of the scope of work. you didn't need us at all... :p

speaking only for myself here, that "high number" you mention up there ^^?
can you add 25% to it, so we don't have to watch you crawl in here naked and
bleeding afterwards? it's going to be more of a pita than first glance indicates.

thanks.
 
Not sure if its been brought up already, but combining circuits is your best friend. I found that many homes are wired well past 3va per square foot, and if the HO isn't using space heaters, you will get away with it. Hey it might even eliminate a few MWBC.
 
What is on the "back side" of the wall where the current panel location is? That is a potential easier place for relocation if it is acceptable to place it there.
 
mbrooke said:
Not sure if its been brought up already, but combining circuits is your best friend. I found that many homes are wired well past 3va per square foot, and if the HO isn't using space heaters, you will get away with it. Hey it might even eliminate a few MWBC.
Click to expand...

Post #7.

~~~~~~~~~~~~~~~~

Coppersmith, if you're going to be stripping out a bunch of UF cable, you ought to order online the UF stripper from Home Depot. It will save a lot of time, it's a lot safer than a razor knife, and makes for much better looking work. none of the Home Depot's I've been to carry it in store, and it only cost like 10 bucks.
 
JFletcher said:
Post #7.

~~~~~~~~~~~~~~~~

Coppersmith, if you're going to be stripping out a bunch of UF cable, you ought to order online the UF stripper from Home Depot. It will save a lot of time, it's a lot safer than a razor knife, and makes for much better looking work. none of the Home Depot's I've been to carry it in store, and it only cost like 10 bucks.
Click to expand...

This one? Does it really work well?

https://www.homedepot.com/p/Gorilla...f+stripper}:st++cn:{0:0}++uf+stripper+{rest}+
 
kwired said:
What is on the "back side" of the wall where the current panel location is? That is a potential easier place for relocation if it is acceptable to place it there.
Click to expand...

I didn't look there so I'm not sure. Just spoke with HO and gave him my price. He asked if he could demo the cabinet around the inside panel and we do a standard panel replacement. Apparently, "a high number (without the 25% adder)" is outside his budget. I then gave him a quote for standard panel change. Waiting on a reply.
 
al hildenbrand said:
For decades, I stayed away from this line of products, as well. . . When I apprenticed, my old Master / Elec Contractor almost always installed GE and I had enough experience with it to happily commit to other brands.

However, with the advent of their AFCI combination-type breaker, which is PURE AFCI, meaning, there is zero ground fault sensing in the breaker (unless it is a Dual Function GFCI / AFCI), I had to re-evaluate my stance.

The problem of placing AFCI on an existing dwelling's existing branch circuits is the possibility of wiring mistakes that have collected in the Premises Wiring (System). Cross neutraling and accidental neutral-ground connections will play havoc with all the other manufacturer's AFCIs because of their ground fault detection. That leads to un-quantifiable troubleshooting that may, or may not, be required.

Having faced this myself, I have chosen not to have to explain the possible need to "go hunting" in the undisturbed wiring of the homeowner's dwelling, and, rather, explain that I am offering the most stable of the new safety AFCI overcurrent protective devices.

For adding AFCI to undisturbed existing branch circuits, I don't think there is a better solution. Just my opinion.
Click to expand...

You make a good case. It's really too bad GE breakers look like trash brand new out of the box. I would definitely consider using GE to avoid untold troubleshooting.
 
Besoeker said:
Ignorant Brit strikes again....
gnarly panel?
Click to expand...
:D Heh!

Think of the gnarled wood of the trunk of a tree as it transitions into the roots. Gnarl is the root of gnarly.

Gnarly became popular back in the '60s with the surfing culture of California and quickly became popular parlance. It is a term for extreme challenge, or extreme danger, or extreme beauty, or combinations of these.
 
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