Approximately 8 years ago I built (with the help of a contractor) a
1,200 sq. ft. shop detached from our home (nice shop with central heat
and air, half bath, hot water, etc.).
Our home has a 200 amp box so I simply put in a 100 amp breaker and run
it to a sub panel in the new shop which has a 100 amp breaker box.
Everything in both the shop and house has worked fine since the
beginning and still does but I did find something somewhat unique.
I have one item in the shop that draws 23+ amps on a 115 volt circuit
and to my surprise had never popped a 20 amp circuit breaker. All
outlets and lights are wired with #12 wire so I know that 23+ amps is a
bit too much but so be it. Well, I moved the item a small amount and
happened to plug it into a different outlet which happened to be on a
different breaker and it popped the breaker after running for about 20
minutes. Tried it again and the same thing happened. Out of curiosity I
checked the voltage and that particular circuit (the one that the
breaker pops on) has 125 volts and all of the others run in the 115/117
Anyone have a clue of how this could happen when they are all coming out
of the same box and are approximately the same distance from the box?
BTW - if you intended reply contains the word "code" or "insurance"
please don't post as it has nothing to do with my question.
Clare pegged it, You haver a loose neutral. Try checking it at the
main lugs. If it is bad there call the PoCo. If it is bad at your sub,
investigate your neutral connections or look for a serious load
On Sat, 26 Dec 2015 00:58:19 -0500, firstname.lastname@example.org wrote:
It's possible there is a neutral problem, but you could just have a pole
transformer that is not exactly center tapped. There could also be some
load on one leg, pulling down the voltage. Measure the voltage at the
MAINS on both legs with everything turned on. Then do it again with
everything turned Off.
If it's still unbalanced with everything OFF, it's just a transformer
that's a little unbalanced. Not to be worried about, if that's all it
You did not say what the device is, which is using 23A, but you'd be
wise to run #10 wire and use a 30A breaker for that device. It would
help of we knew what it is, because a motor load can vary from when it
starts up to when it's running, while a resistive load, such as a
heating device has a pretty continuous power draw.
And if it's something like an air compressor, they can use a bit more
current after the tank gets full, causing a heavier load on the motor
(and when it starts in cold weather). I had to repair some air
compressor wiring for a guy who said in the summer it worked fine, but
in cold weather, it tripped the breaker. It was obvious that the cold
compressor would not allow the motor to get up to full speed when it
first started. The solution was to either move the compressor into a
heated space, or use a bigger motor and upgrade the wiring to a heavier
gauge wire and bigger breaker. A motor was costly, and the wiring
upgrade even more money. He said he could not afford to heat his garage
all the time. I suggested moving the compressor to his basement and just
running a longer air hose to his garage thru a small piece of pipe in
his foundation, and cauking around it, or even putting an air chuck on
the foundation wall.
He decided to move the compressor to the basement, so all I had to do
was run a dedicated outlet for it from his panel. He said he's buy more
air hose and just stick it thru a basement window because it was just
for occasional flat tires.
On Sat, 26 Dec 2015 03:59:28 -0600, email@example.com wrote:
They don't arbitrarily "center tap" the transformer wherever they
want,. It is wound at the factory and it will be tapped exactly at the
This looks more like a 5-6% voltage drop in the neutral.
That is far beyond the NEC recommendation and the utility standard.
-----BEGIN PGP SIGNED MESSAGE-----
One circuit 125V, others 117V, why?
Every Phase have his own Voltage
Chat / Irc irc://gallaxial.com:6667/general
Come With Friends of same interest
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
-----END PGP SIGNATURE-----
Unlike you (apparently) and the Jesus freak with 5
wives and door knocker I don't give a rats ass
about the poor in Africa. Their leaders don't
why should I??
I tend to me and mine the rest can get a job or
die makes no difference to me.
Not even for a minute as long as people like you
are not actively engaged and their leaders don;t
give a shit.
Pack a bag, gather your wives and go knock on
some HUT doors for 3 years then we can talk.
Global warming believer == quasi-religious nutter and/or useful idiot
"Global warming is hooey." -- Reid Bryson, father of modern climate science
"Climate policy has almost nothing to do anymore with environmentali
protection. The next world climate summit in Cancun  is actually
an economy summit during which the distribution of the world's resources
will be negotiated." -- Ottmar Edenhofer, co-chair IPCC working group III
Roger Blake (Posts from Google Groups killfiled due to excess spam.)
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.