I'm going to upgrade my electrical service from 100A to 200A. New
meter, new panel and all that. What I want to know is wheter I can
leave the old breaker panel on the wall with the new one mounted next
to it, using the old one as a junction box so I don't have to move all
those wires (which will inevitably be too short) to the new box.
This way, I could put a couple of pieces of pipe between the two
panels and wire nut extensions to each wire in the old panel to bring
it over to the new,
Is this kosher? Would I also pull out all the bus bars from the old
box? Do I have to screw its cover closed?
There will be a licensed electrician and permits for this work, but
I'm looking to do a bunch of the grunt work myself to save a few bucks
and maybe learn something along the way,
On May 31, 9:53 pm, " firstname.lastname@example.org"
What is the point of doing that ?
For a couple of spools of wire in various colors and wire gauge sizes,
the OP can have all of the circuits fed from the new panel...
Most of the circuits in the old panel will be run using #14 or #12
with a few using larger size wire for major appliances... Running the
existing panel as a sub panel would require moving some of those
loads and running a new feeder for the sub-panel... Much easier
to just use the old panel as a junction box and be done with it...
On Mon, 31 May 2010 22:28:53 -0500, " email@example.com"
My read on it is if the wires are too short to reach in the new panel
it can be a LOT of work - so using the existing banel as a junction
reduces that work considerably. Using it as a sub panel does not solve
the "likely" problem that caused him to consider replacing the panel -
either fuses or old breakers and possibly deteriorating panel
If the wires are not too short, and are in good condition, moving all
the circuits from the old panel to the new is ONLY a couple hours
Last one I did was only about 2 hours total - most of it in the dark,
all of it in the cold, with the service live.
Electric heat and all.
True most of the time... I guess you have never seen a panel that has
been corroded by exposure to an excessively moist basement...
If the panel enclosure is stable and not corroded it can be used as
a junction box, just ask the inspector what sort of covering they
want to enclose the front...
re: "I guess you have never seen a panel that has been corroded by
exposure to an excessively moist basement"
..or by water that found it's way into the panel via the service wire.
Water was getting inside the insulation of the main at the bugs and
finding it's way into the box, dripping in right above the main
breaker. Even though the service wire did have a few "uphills" along
the run, the water made it through anyway.
The quick fix - before the service was eventually replaced - was a
very small slit in the covering of the service wire at it's lowest
point, which was just below the meter. When the homeowner slit the
jacket, water dripped out for a few minutes and then stopped. It was a
year before he had it replaced and he never got another drop in the
breaker box after the slit was made.
I have only seen the aftermath of water infiltration to a 277Y480
used for lighting when water from a fire sprinkler discharge got into
a panel and blew it up, the water dripped in just right to make
round holes in several of the breakers... Looked like a bullet hole
a .22LR... All because of a 3/4" KO that was left open after a
and its conduit was removed and no one double checked at the time
that the panel enclosure was patched with a metal plate or
For want of an item worth a couple of dollars a $10,000 emergency
repair, partial rewire and cleanup was required...
On Jun 2, 8:44 pm, firstname.lastname@example.org wrote:
OK guys, let me clarify, and then add a question.
The old box is a Federal Pacific 100A. I haven't had any problems with
the breakers - they trip when they should, but when I go to sell the
house, I know it's going to be an issue. Also, the panel is full. I
need to add more circuits. There's already a sub panel with 6 circuits
next to the main. The existing wires (old BX, some going back to the
late 1920s, some to the 1960s) are almost certainly too short to work
in a new 200A box. If I don't use the old box as a junction box, I'd
just have to mount another large junction box (or several smaller
ones) in its place. There's no way I'm going to pull new cable for all
Though I CAN be down for a while, running on a generator, I'd rather
not be. I was thinking that a plan would be to get the new box & meter
pan installed with just a couple of utility outlets nearby. Then I
could have the power company come and switch the service over to the
new meter, then I could backfeed from the new box to the old box.
At that point, the house is powered, and I can proceed with extending
the circuits to the new panel, one at a time. When all that's done,
I'll remove the backfeed and take out the guts of the old box and
screw its door shut. At that point, I can start adding the new
circuits I need.
Does that sound like an OK plan?
Now, my question:
When extending the circuits from the old box to the new one, do I also
extend the individual ground wires, or can I leave them on the bus bar
and rely on the conduit (actually, in all likelihood, this will be two
or three 1" or so nipples) to continue the ground?
In the end, it's going to be up to the electrician, but I want to go
into this with a good starting point for discussion.
Yup. Probably the easiest way. and fastest to get everything repowered
temporarily. Probably good, in particular, for do-it-yourself.
Nice information you got from your inspector.
If there is room for the new service wire feed, the new panel can be
placed where the old one is, with the old circuit wires coming into the
top of the new panel. If the old circuits are BX and Romex it is
relatively easy. If EMT, lining up holes can be a pain. It is longer
time until everything is refed. The electrician may rather do it this way.
It would be code compliant. I would rather add a wire, maybe #6. I
believe if all the circuit wires were #12 or smaller and you connected
the panels with PVC. the NEC would only require a single #12 ground wire
to the old panel - probably would be a good way to make the inspector
Many wires in conduit requires derating of the wire ampacity. If the
pipes are 2' or less in length derating is not required. Since you
called them nipples you are probably know that.
Since the electrician is pulling the permit, he may not want you doing
some of the work. Helping, or even watching. is a great way to learn. I
think I may have driven some tradesmen crazy.
I always like to know what the considerations are before talking to
someone who will do any work.
On Thu, 3 Jun 2010 06:17:25 -0700 (PDT), rangerssuck
Just a couple questions - do all the cables come in one side of the
100 amp panel, or do they come in both sides? Most FPE integrated
entry panels do not allow cable entry from the service side - so I'd
assume yours all come in either top, bottom, or right side (most FPE
integrated panels have the main on the left).
If this is the case, simply move the panel 6 inches to the right, and
every cable will be lots long enough to fit. If the cables are bottom
entry you may need to use the lower breaker positions for those wires.
And for the other guys - why would using a suspect panel (the FPE)
which he is replacing due to percieved safety issues as a sub panel be
any kind of a sensible move???.
ANd the 200 amp panel will have plenty of space for existing plus
additional circuits. The "sub panel" wouls shout "mickey mouse" to the
next buyer or their home inspector.
If you're gonna do the job - not only DO it right, but make it LOOK
I agree If it looks right, it probably is right. But:
1) This panel has the main at the top. Most of the wires are fed from
the top, but some are from the left. It's conceivable that I could
pull out the old box and put a new one in its place, but doing so
would involve flexing those old cables a lot, and that scares me. I
did some work in the kitchen recently, and while the old wire wasn't
exactly crumbling, it wasn't very flexible, either.
2) Using the old box as a junction box and mounting the new one next
to it won't look any worse than what's already there. This is an old
house, and it's never going to be a new house without ripping out ALL
the wires and starting over from scratch, and that is simply not going
More important to me, at this time, is to do a good, safe job, and to
have room in the new panel to add a half-dozen or so circuits which
are sorely needed. While the walls were open for plumbing work, I ran
a piece of 6/3 up to the attic so that I can (later) put a sub panel
there to feed some new outlets in the second-floor bedrooms. The old
panel is full. I need a bigger one just to have a place to connect
that 6/3, if for no other reason.
On Jun 1, 8:50 pm, email@example.com wrote:
You're assuming information not in evidence. The OP simply said that
he was upgrading the service from 100A to 200A. It is quite possible
that there is nothing wrong with the current panel. Using it as a sub
would save considerable work.
Again, you're assuming information not in evidence. Wires are
*always* too short to go where they weren't intended to go. Some may
reach, move those. If he's blessed and they all move without
"stretching" the whole point of the sub/j-box is moot.
No, the wires are NOT alkways too short, if you remove the old panel
and replace it with a new panel, in the same place. I've done it
numerous times. I've only ever had one or two wires that could not be
made to reach in the new panel, in all the panels I've replaced. And
by "made to reach" I don't mean stretched across the corner or
anything. Always looked professionally done when finished.
On occaision it meant using the bottom couple of breakers, along with
all the rest closer to the top of the panel instead of all bunched
together. When I finally replace my fuse panel, the stove and dryer
breakers will be at the bottom of the panel, because that's where the
220 pullouts are in my old fuse box.
On Jun 3, 2:19 pm, firstname.lastname@example.org wrote:
There is no legitimate reason to disturb wiring from the 1920's or
unless you absolutely have to do so... You could find that the wiring
has not aged gracefully and could require replacing the homerun to
the panel for several circuits if the wires become damaged when you
remove them from the old panel and insert them into the new panel
in the same location OR try to reroute them to a new panel located
adjacent to the old one...
So leaving them in place and using the old panel as a junction box
after it has been gutted is the best most efficient way to deal with
the situation the OP has described...
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