String of events

junkhound

junkhound

Senior Member
Location
Renton, WA
Occupation
EE, power electronics specialty
80 YO church pasonage.

1/2 of house goes dark,

Old dual bus GE panel, 2 ea 50 A 240 breakers feed A and B single phase breakers.

Old linen wire in conduit.

a. electric razor uses same outlet in bathroom for many years

b. 6-23 screws holding receptacle become loose after a few decades

c. top retaining screw head works thru outlet top slot, now a 1/8" movement possible every time electric shaver used.

d. more years - linen wears thru where bearing against box, short

e. BOTH 20A branch and 50A sub main breakers trip.

f. happily, enough slack in box to trim linen wire and reterminate, replace outlet, etc, all is well.
 
D

__dan

Banned
Those guys who ran two wire in conduit back then knew what they were doing.

Could have easily been an ungrounded circuit residential from back then, but a good guess would be the church spec was conduit and the parsonage was constructed at the same time to the same spec. House next door would not be conduit.

Throw in the old breakers that may or may not open, or open slow, that conduit is what saved the day, and carried enough fault current until something upstream could open.

Also a good guess would be the conduit did not allow a Voltage raise at the remote point, on the EGC, and all of the drop was on the branch circuit, limiting shock hazard on anything bonded to it. A lesser or no EGC circuit would have gone up in Voltage on the bonded exposed metal, and in the bath oohhh ...

Thank the guy who specc'd conduit for the job and the guys who installed it.

Could have been shock or fire or both or worse (it is 2024, things have been getting worse).
 
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