Did you measure 50V with all the load turned off or only with the panel loaded?
Measured with panel loaded.
(Thinking backfeed from another phase via a 208V piece of equiptment)
Yeppers, the A/C unit! (I forgot to mention that I had turned the A/C breaker on during my measurements.)
Without a load, I'm assuming you might get a normal voltage read, but resistance from a bad connection is dropping your C phase voltage.
Nope, no load voltage was around 14 with a/c breaker off, but would rise when a/c breaker was on. Very odd. I think that it was backfeeding thru the a/c unit into the dead phase.
**Edited to answer Mike's questions: Nope, all was clean and tight in the disco, no heating evident. The idea to cycle the disco was just a hunch on my part, who knows what evil lurks in the contact area?
![[Linked Image]](https://www.electrical-contractor.net/ubb/smile.gif)
What brand was the disconnect? I'm assuming 80A fuses were installed.
Square D and yes, those were 80 amp fuses. Gould "One Time" OT-80 {Well, duh. most fuses are one time.} I went out and got a set of Ferraz Shawmut 80 amp "Smart Spot" Current limiting fuses as spares. They have a window on the side that goes red when they blow. Looks like a small piece of foil covers a red underlay and the foil vaporizes as the fault current tries to pass thru. Maybe I'll pick up another to open it and see if my guess is right.
And to save the rest of the suspense, rewired got it with choice #2. (Although as WFO guessed right off, it was a bad meter connection. But we couldn't stop there, right?
) Not to mention when I figured it out, my B-I-L decided to try to whack the meter with a hammer!! (He's a bit of a loose cannon with electricity). I warned him not to even touch the meter, as if it goes into arc fault the results will be ugly. I then told him about the time I had a form 2S meter blow on a resi service change.
So, it's a "lemon-entry", Watts-on.
Sherlock
ROFL Alan!!
What really surprised me about this whole caper is that according to POCO, the meter was changed over three years ago when a truck backed into and destroyed the original disconnect (despite the safty bollards, no less) and the meter can was changed. {I was told the fireworks were quite a show, lasted till POCO could arrive and cut the feeder to the gutter.} The meter base evidently has a twist-lock thing going on and wasn't fully locked in. The damage from this latest wasn't that bad I guess as it is still the same meter and can.
It is a 120/208 wye service.
I knew this group would get it quick!
[This message has been edited by mxslick (edited 01-16-2006).]
