JohnJ0906
Senior Member
- Location
- Baltimore, MD
I want to run this past you all and get some input.
Service call today at a commercial establisment, approx 15 seperate suites. 1 suite totally without power, boss sends me out.
Customer says they heard "a loud pop" from the back, and power went out. also thermostat had acted "squirlly" when they got there in morning
Went to the suite,208/120 3 ph MLP,Challanger brand, no breakers tripped, no voltage. Went to the meter room, Challanger meter stacks, 150 amp 3 ph Challanger breaker in "ON" position. No voltage load side, when I tried to move to "OFF", stopped in middle posion and wouldn't budge. Luckily there were several meter sockets not being used, so I could swap breakers. No shorts on the feed, reenergize panel in unit with everything off, Now I have power.
Turn on 120 breaker 1 by 1, everything works. I am left with:
Turn on water heater, run water, heats it, OK.
For the HVAC equipment, I went to each 1 at a time, checked fuses, checked for shorts in the feeder, reenergize w/ disco off, all OK.
I turned furnace and ductheater back on, but I didn't turn on RTU, I didn't see any damage, but it had a fair amount of rst on the compressor.
I told the customer to have the HVAC system checked carefully, because my best guess was that a fault in something caused the problem, or it could have been that the main breaker had gone bad.
My questions- If a peice of equipment faulted bad enough to trip a 150 amp main breaker, AND render it inoperable, why not also trip the individual breaker as well, and why not the fuses?
-If the main breaker just decided to go bad, why would the customer hear a "POP" with 2 suites, and at least 1 block firewall between her and the breaker?
And the big question-What the @&%#$ did I miss here?
Thank you in advance for any and all replies.
Service call today at a commercial establisment, approx 15 seperate suites. 1 suite totally without power, boss sends me out.
Customer says they heard "a loud pop" from the back, and power went out. also thermostat had acted "squirlly" when they got there in morning
Went to the suite,208/120 3 ph MLP,Challanger brand, no breakers tripped, no voltage. Went to the meter room, Challanger meter stacks, 150 amp 3 ph Challanger breaker in "ON" position. No voltage load side, when I tried to move to "OFF", stopped in middle posion and wouldn't budge. Luckily there were several meter sockets not being used, so I could swap breakers. No shorts on the feed, reenergize panel in unit with everything off, Now I have power.
Turn on 120 breaker 1 by 1, everything works. I am left with:
- Furnace, 3 ph, 60 amp fuses
- Duct heater, 3 ph 40 amp fuses
- RTU, 3 ph, 30 amp fuses
- Water heater, 1 ph, 30 amp breaker in panel
Turn on water heater, run water, heats it, OK.
For the HVAC equipment, I went to each 1 at a time, checked fuses, checked for shorts in the feeder, reenergize w/ disco off, all OK.
I turned furnace and ductheater back on, but I didn't turn on RTU, I didn't see any damage, but it had a fair amount of rst on the compressor.
I told the customer to have the HVAC system checked carefully, because my best guess was that a fault in something caused the problem, or it could have been that the main breaker had gone bad.
My questions- If a peice of equipment faulted bad enough to trip a 150 amp main breaker, AND render it inoperable, why not also trip the individual breaker as well, and why not the fuses?
-If the main breaker just decided to go bad, why would the customer hear a "POP" with 2 suites, and at least 1 block firewall between her and the breaker?
And the big question-What the @&%#$ did I miss here?
Thank you in advance for any and all replies.