One circuit 125V, others 117V, why?

Page 1 of 3  
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 range.
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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Friday, December 25, 2015 at 9:31:41 PM UTC-6, IGot2P wrote:

You most likely have a slight difference on each side of the 230 volt panel. Like the center-tapped 115 volt is not exact. No biggie.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/25/2015 8:31 PM, IGot2P wrote:

Not without your further clarifying the conditions under which you are obtaining these measurements!

How, where and UNDER HAT CONDITIONS are you measuring the potential? Have you also looked at the line at the "supply end"?
Wasn't this question asked (and answered) previously?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Friday, December 25, 2015 at 10:48:18 PM UTC-5, Don Y wrote:

+1
If it's with no load, then it would suggest a possible problem with a bad neutral connection. If it's with substantial load, then it could be normal.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Don Y posted for all of us...

YES!
--
Tekkie

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

If one leg is higher than the other, there is likely a neutral problem somewhere and a load inballance.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

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 imbalance.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 26 Dec 2015 00:58:19 -0500, snipped-for-privacy@aol.com 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 is.
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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 26 Dec 2015 03:59:28 -0600, snipped-for-privacy@unlisted.moc wrote:

Huh? 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 center. This looks more like a 5-6% voltage drop in the neutral. That is far beyond the NEC recommendation and the utility standard.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/26/2015 10:31 AM, snipped-for-privacy@aol.com wrote:

Sounds like it's not to code, and will affect the OP's insurance?
--
.
Christopher A. Young
learn more about Jesus
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 26 Dec 2015 10:53:16 -0500

How? You gonna go tell on him?
Why don't you go to Africa and tend the "poor"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256
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
iQEcBAEBCAAGBQJWfsIfAAoJENmA8XzsWXgK+/0H/jQFrdbIB0uFQI9YoVHL00ws Q6jKFAa1+eCR7aWhm/Qpl4Ka+JJyDq4Da8zl52cPHAZy1NxHycPjV+QKOfGDmk3I 240qdS31eaLiO5LCqz2QhovC8NNmJvSep0zA1IR+n2l7z46+eBnjrurzzYS8dYoY VbqPtDvvxLelsHQeHNmS/SPovm/YZlFBr8rcPDe5Tl4eFVHHIugnkQI+HBpsm51e TLO17F552eTn02IkVk3CXZdv7eAXBjtSvUFL2RI0HxdmSZ0MyVM63S6AE4af4QPu oYWDIVjmIuDcFDgSm8A6F+B4IMxcoxWmRWIz5Adj9ZszuEyiNu8AQVESvN5oiFY=vToJ -----END PGP SIGNATURE-----
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

also be balanced.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Saturday, December 26, 2015 at 10:02:51 AM UTC-6, burfordTjustice wrote:

+1
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 26 Dec 2015 09:06:51 -0800 (PST)

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/26/2015 12:24 PM, burfordTjustice wrote:

Mysogynist = woman hater Isolationist = starving children hater
Starving children lives matter!
--
.
Christopher A. Young
learn more about Jesus
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 27 Dec 2015 08:30:29 -0500

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/27/2015 9:48 AM, burfordTjustice wrote:

I am so going to miss you. Where are you going? Seeing as how you won't talk to me, and all?
--
.
Christopher A. Young
learn more about Jesus
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 27 Dec 2015 08:30:29 -0500, Stormin Mormon

Global warming denier = someone who thinks every child should survive.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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 [2010] 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.)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    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.