Ok bear with me this is a long explanation of what I tried to figure out today.
Customer called on Friday and stated that they were testing elevator recalls and such in a 34 story building in Seattle.
They were in one cab and switched off the cab lights with the keyed switch in the cab and 3- 1pole 20 amp gfci breakers tripped in the sub panel feeding all the 8 elevator car cab lights ( 3 phase 60 amp 120/208 sub panel with 8- 1 pole 20 amp gfci breakers , 1 for each elevator car .) the three that tripped were all on one phase. The elevator tech pulled the switch and capped off the hot ,reset the other two breakers and tried resetting the breaker for the car they were working on.All three breakers tripped again. Put switch back together turned it back on , reset all breakers and they stayed on .
When I showed up this morning we turned keyed switch off , all three breakers tripped.Turned switch on,reset all three breakers ,started pulling the compact flourescent lamps out one at a time .( 8 -can lights ,6 have 5 watt lamps , 2 have 14 watt lamps. ) pulled all 5 watt lamps, got to one of the 14 watt,pulled it and all three breakers tripped again. put the 14 watt lamp in different can light, reset breakers , pulled the 14 watt lamp again ,breakers tripped again.
Tried various combinations of lamps and without any lamps installed , breakers trip without at least one of the 14 watt lamps installed. Can't isolate the problem to any 1 can light.
Tried shutting off the keyed switches and pulling lamps in the other two cars that kept tripping , no tripping .
Customer called on Friday and stated that they were testing elevator recalls and such in a 34 story building in Seattle.
They were in one cab and switched off the cab lights with the keyed switch in the cab and 3- 1pole 20 amp gfci breakers tripped in the sub panel feeding all the 8 elevator car cab lights ( 3 phase 60 amp 120/208 sub panel with 8- 1 pole 20 amp gfci breakers , 1 for each elevator car .) the three that tripped were all on one phase. The elevator tech pulled the switch and capped off the hot ,reset the other two breakers and tried resetting the breaker for the car they were working on.All three breakers tripped again. Put switch back together turned it back on , reset all breakers and they stayed on .
When I showed up this morning we turned keyed switch off , all three breakers tripped.Turned switch on,reset all three breakers ,started pulling the compact flourescent lamps out one at a time .( 8 -can lights ,6 have 5 watt lamps , 2 have 14 watt lamps. ) pulled all 5 watt lamps, got to one of the 14 watt,pulled it and all three breakers tripped again. put the 14 watt lamp in different can light, reset breakers , pulled the 14 watt lamp again ,breakers tripped again.
Tried various combinations of lamps and without any lamps installed , breakers trip without at least one of the 14 watt lamps installed. Can't isolate the problem to any 1 can light.
Tried shutting off the keyed switches and pulling lamps in the other two cars that kept tripping , no tripping .