Leejosepho
DIY scratch-pad engineer
- Messages
- 2,483
- Reaction score
- 0
- Points
- 36
- Location
- 200 miles south of Little Rock
- Website
- www.nonameyet.org
All had been well since our service upgrade a few weeks ago, and I have not messed with anything since.
About one week ago and right after I had gone to bed, my wife and I heard three or four buzzing sounds coming from our breaker panel in an adjoining bedroom, and then the 30A breaker for the underground subfeed out to my workshop (with its own panel) tripped. After resetting that breaker and nothing more happened, I just flipped it back off and let it be until beginning to check things out today. There had been no load or demand of any kind at the workshop when that breaker had buzzed a bit and then tripped.
Today:
1) The subfeed's breaker had an ugly-looking terminal, and replacing that breaker with a new one made no difference.
Note: I still had no lights working out in the workshop, and I did not think to check for power on the other incoming leg.
2) I next disconnected the underground workshop-feed from its junction box on the outside of our house.
3) Power coming out to that junction box is fine. (and breaker is now off again)
4) My meter shows no short (no continuity) between the black and red wires going out to the workshop.
5) I did not check either feed line for continuity against the white wire (neutral).
6) With the underground red and black wires twisted and nutted together (at the house end), I get at least 1400 ohms resistance at the workshop end ... and that number climbs continually for as long as I hold my meter on the wire ends at workshop panel. (main-breaker terminals)
7) Until today after digging it up, the first couple of house-end-feet of the underground wire to the workshop had been laying inside a rusty, water-filled conduit for a long time.
8) I have yet to find any damaged insulation (jacket) on the underground feed wire going out to the workshop.
My guess is that I am going to have to replace the underground wire going out, and I suspect that resistance I have found is coming some kind of compromise in either the black or red wire going out.
Note: There was no rain or anything else going on at the time the subfeed wire apparently shorted somewhere underground and tripped its breaker.
Am I missing anything here?!
I thank you!
PS: For anyone who might get a chuckle here, this all happened just an hour or so after my mother-in-law had passed away ... and then my wife actually said: "Oh oh, Dad's complaining again already!"
About one week ago and right after I had gone to bed, my wife and I heard three or four buzzing sounds coming from our breaker panel in an adjoining bedroom, and then the 30A breaker for the underground subfeed out to my workshop (with its own panel) tripped. After resetting that breaker and nothing more happened, I just flipped it back off and let it be until beginning to check things out today. There had been no load or demand of any kind at the workshop when that breaker had buzzed a bit and then tripped.
Today:
1) The subfeed's breaker had an ugly-looking terminal, and replacing that breaker with a new one made no difference.
Note: I still had no lights working out in the workshop, and I did not think to check for power on the other incoming leg.
2) I next disconnected the underground workshop-feed from its junction box on the outside of our house.
3) Power coming out to that junction box is fine. (and breaker is now off again)
4) My meter shows no short (no continuity) between the black and red wires going out to the workshop.
5) I did not check either feed line for continuity against the white wire (neutral).
6) With the underground red and black wires twisted and nutted together (at the house end), I get at least 1400 ohms resistance at the workshop end ... and that number climbs continually for as long as I hold my meter on the wire ends at workshop panel. (main-breaker terminals)
7) Until today after digging it up, the first couple of house-end-feet of the underground wire to the workshop had been laying inside a rusty, water-filled conduit for a long time.
8) I have yet to find any damaged insulation (jacket) on the underground feed wire going out to the workshop.
My guess is that I am going to have to replace the underground wire going out, and I suspect that resistance I have found is coming some kind of compromise in either the black or red wire going out.
Note: There was no rain or anything else going on at the time the subfeed wire apparently shorted somewhere underground and tripped its breaker.
Am I missing anything here?!
I thank you!
PS: For anyone who might get a chuckle here, this all happened just an hour or so after my mother-in-law had passed away ... and then my wife actually said: "Oh oh, Dad's complaining again already!"
Last edited: