Fulthrotl
~Autocorrect is My Worst Enema.~
- Occupation
- E
customer of mine has a marina. still does, lucky man.
it didn't burn to the waterline.
the other day, there was a bolted fault short inside a 2" GRC
conduit feeding one section of marina. harbor patrol noticed
smoke, and could see what looked like a signal flare burning
on the dock, visible from 100 yards away.
wooden dock, with pretty much full occupancy. lotta boats
tied up, some with live aboards.
seems a 3/0 copper feed with kearneys tapped off in 2" T's
went to ground, welded itself there, and as there wasn't a
good enough ground path to fault the 200 amp fuse and open
the circuit, just sat there burning. the resistance at the couplings
from rust got them hotter than the other parts of the pipe, and that
is where some of the flames were coming from. it seems that the
split bolts were taped with what looks like 79 cent plastic tape,
witout rubber tape or varnished cambric, and the high current flow
started melting them in the condulets working their way back to the
panel. as they began shorting out, it provided a better path to ground,
and finally enough current flow occurred to open the cartridge fuse.
it would seem that new conduit, wire, and dock boxes are in order.
awaiting communication from the owner about what course of action
he wishes to take.
here is the bolt at fault:
here are some more photos of the conduit condition:
it didn't burn to the waterline.
the other day, there was a bolted fault short inside a 2" GRC
conduit feeding one section of marina. harbor patrol noticed
smoke, and could see what looked like a signal flare burning
on the dock, visible from 100 yards away.
wooden dock, with pretty much full occupancy. lotta boats
tied up, some with live aboards.
seems a 3/0 copper feed with kearneys tapped off in 2" T's
went to ground, welded itself there, and as there wasn't a
good enough ground path to fault the 200 amp fuse and open
the circuit, just sat there burning. the resistance at the couplings
from rust got them hotter than the other parts of the pipe, and that
is where some of the flames were coming from. it seems that the
split bolts were taped with what looks like 79 cent plastic tape,
witout rubber tape or varnished cambric, and the high current flow
started melting them in the condulets working their way back to the
panel. as they began shorting out, it provided a better path to ground,
and finally enough current flow occurred to open the cartridge fuse.
it would seem that new conduit, wire, and dock boxes are in order.
awaiting communication from the owner about what course of action
he wishes to take.
here is the bolt at fault:
here are some more photos of the conduit condition: