A contractor had to put in a sub-panel in my home because the main box
was full. I have a few questions on what he did that I hope some
experienced electricians can answer.
The new sub-panel is located immediately (about 4") below the main
panel and connected to it with metal conduit. To feed the sub-panel,
two existing circuits were removed (and replaced by a dual-pole
breaker) and those existing circuits were extended to breakers in the
1 - Do the neutral and ground need to be separated in this sub-panel?
He bonded them. Most info in the NEC talks about sub-panels in
separate buildings or at remote locations. I don't know if the
situation changes if the sub-panel is located so closely to the main
2 - The hot wires for the moved circuits were extended into the
sub-panel. Do the neutral and ground wires need to be extended also?
He left them in the main panel and only extended the hot wire.
3 - Given that 2 20A furnace branch circuits (A/C operation and
_electric_ heat) were what was moved, and two additional 20A (patio and
landscape lighting & power) branch circuits added, what is a suitable
breaker to feed the sub-panel? He put in a 25A and wired the sub-panel
with #10 wire, which seems a bit light considering the 2 furnace
Thank you for any clarification on these issues.
Absolutely not bonded together in a sub panel. This guy is an electrician,
Neutral should be isolated from ground, fix this as soon as possible. Not
that your house will burn down it is just not the right way to do it.
It is a good idea. A craftsman would do it.
Need to do a load calcualation on the service then on the additional loads.
Not what size the breaker is what the acutal load is. 25 amp breaker not
what I would have used (30).
Figuring the heaters are on each phase (balanced loading) and the patio
circuits are the same then it will work just fine. Odds are when the patio
is under a load the heaters will not be used.
What did you pay for?
Yes, that is the case; I specifically made sure of it when I went into
Not really true -- we're in Texas, so we may be running the heaters in
the house and still be using the patio, fan, landscape lighting, and
fountain outside. :)
A learning experience it seems. Originally I did not want to mess
around with the main panel so I hired this guy who was recommended by
the contractor doing the rest of the landscaping work, but I was so
bothered by the final electrical work that I redid almost all of it.
I've not mentioned how he used white wires for hot leads (without
marking them in any way), how he installed the fan in the arbor without
a GFCI and without the wet location kit supplied in the box (both which
I've since added, and which it clearly calls for), how he fed the wire
to the fan through a whole drilled straight up through the mounting
board on the arbor (allowing rain to run right down the wire into the
fan), how he ran the hot from one circuit but the neutrals from two
different circuits through the load side of the one GFCI he did
install, how he ran exposed standard household cable across the arbor
for the fan rather than wet and sun rated cable, nor how he used a
mixture of 4 hole metal and 2 hole plastic weatherproof boxes which
looked horrible and which I've all replaced with the same plastic
weatherproof boxes. I've since fixed all of this.
In the end, I was not explicit enough with what I needed installed,
trusting him to know what he was doing and to care enough to do the
best job, neither of which it seems were really the case,
Thanks for answering my questions and verifying my concerns.
Was your "contractor" a licensed electrician?
If he made that many errors I think that before correcting things you
should have weighed whether your need to stay on speaking terms with him
was worth more than the risk that his slipshod ways might create a real
life threatening situation on the next job he did.
I would have asked him to correct things pronto, and if he gave me any
BS about it being ok as is, I'd have asked the local electrical
inspector to drop over and look at the job. There are times you just
have to stand up and be counted, even if it makes some other people
think you're a creep.
I may have already bloviated on this group about last spring's adventure
with an HVAC tech who, while replacing a couple of Heat Pump compressor
units at our home, used one of the outdoor fused disconnect switch
housing as a "splice box" for the low voltage control wiring to the
I e-mailed that photo of what he'd done to his boss, and the next day
the job was made right by a different tech who installed a separate
weatherproof splice box for the control wiring.
Now, what the first tech had done would probably have worked fine
forever if nothing fell apart inside that switch box, but it wasn't to
code. And, if I ever get a chance to retire and sell the place before I
die it would be my bad luck to have the buyer's home inspector decide to
eyeball that disconnect switch and then force me to have to hire and pay
a licensed electrician to make it right.
Just my .02,
Jeff, good post, but my need to nitpick kicked in ;-)
To be fair, nothing he did was particularly dangerous. With the panel so
close to the main panel, it's really splitting hairs as to why the grounds
need to be separated. If it's in another room/building/whatever certainly.
Not defending the guy's work, since it wasn't to code, but it isn't really a
safety problem that I can see...
Contractors are not immune from electrical inspections -- the inspector
SHOULD have dropped by. This was yet another violation.
They can't FORCE you to do anything. At worse, they could back out of the
sale. If this situation had come up in a sale and they wanted it fixed, you
can be darned sure I'd be fixing it myself, unless of course they want to
pay to have an electrician do it. I think just about every house has some
sort of 'violation' like this, so I think if a buyer were that picky, they
wouldn't be finding any home. But I can't blame you for making sure it was
As an aside (and I have no idea if this meets code or not), the low-voltage
wire from our HVAC unit to the outside unit is standard romex! I was poking
around in the ceiling of the utility room one time and was shocked (not
literally, thankfully) to find a wirenutted connection from the romex to a
standard T-stat type wire!
I agree that FORCE was too strong a word. But if the situation occurred
while we were in the "short strokes" of closing on the house, then I'm
pretty sure I'd do whatever necessary even if it cost a few hundred
bucks for Alec (Alec Trician) to keep us from having to start over again
attracting a buyer for a (not bragging) million buck home.
And while I damn sure could do it myself, and probably neater and more
workmanlike than that second HVAC tech did last spring, I believe the
buyer's lawyer would be within his rights to require that the work be
done by a licensed electrician, which I'm not; An MSEE from '58 don't
count for that. :-)
I'm guessing that your compressor unit requires just a simple relay
pull-in needing only two conductors, or did they use multiple pieces of
I'm not a licensed expert, but I can't think of any technical reason why
Romex wouldn't be fine.
You just reminded me that about ten years ago when I had to find out
what was wrong with one of our heat pumps I discovered after many
mutterings of "WTF" that when we built the house the sods who'd run the
five conductor control line to the compressor unit I was fixing had to
have made a hidden splice in the control cable between the air handler
and the compressor.
The insulation colors on two of the five leads "changed" from one end of
the run to the other. After about an hour ringing them out (I was
working alone at the time) I found and replaced the relay with an open
coil, which was the real problem, and all was well.
I put a note about those chameleon wire colors in my household "HVAC" file.
I think bonding the neutral and ground is subpanels is a relatively
common code violation, but an electrician should know better. If you
havn't already, check for a "main bonding jumper" from the neutral bar
to ground - usually a screw. The subpanel can be grounded by the rigid
pipe and doesn't need a separate wire.
This is NOT necessary. Neutrals have to be run with hots so the total
current (with current going in one direction cancelling current going
the other direcction) is zero in a pipe or knockout. The current in the
hot load wires returning from the panel will cancel an equal current in
the supply wires so the total current is zero.
Make sure the subpanel is rated for 40A (most likely is). Given the low
cost of a higher amp feed and the original panel being maxed out, it is
kind of dumb to only run the subpanel at 25A.
#1 and #2 are both wrong, but they are also perfectly safe in my opinion
(assuming that conduit connecting the 2 boxes is a rigid or IMC conduit
and has threaded locknuts.) The new box is supposed be wired as a
subpanel. I'm not sure that I would change it though. What did the
electrical inspector say?
I would have used #6 copper wire and a 50A or 60A breaker. I wonder
where he found a 25A breaker instead of a 30.
Of course the contractor is going to tell you that. They don't want
anyone inspecting their work.
The panel wasn't that bad, but the other stuff you mentioned is scary.
It's probably too late now because you've fixed everything and there's
no evidence left, but I'd file a complaint and try to get the
"electrician's" alleged license suspended.
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