Twister
Member
- Location
- Canton, MA
- Occupation
- Electrician
Was called to check a panel ,service disconnect for a fresh air intake. The panel is GE 3 Ph. 480VAC with 400A main. Noticed a few very strange things! 2 spaces on the bottom of panel board has KO's with labels "Do Not remove,Do Not Install", inside on the very bottom behind those Ko's on all busses there are Tamper Proof screws preventing C.Breaker installation. Someone managed to remove 1 of the KO's (twist/break) and the screws ,installed 3 pole breaker leaving 1 space bellow empty with Tamper Resistant screw.The breaker that was installed tripped taking down fresh air intake system connected to it. A/C Co. technician went up on the roof and turned OFF a service disconnect on the unit then went back to the panel and reset the breaker.The breaker reset but when he went back to the rooftop unit and tried to turn service disconnect on it just blew up but the breaker inside the panel feeding it did not. Im not an A/C guy to start troubleshooting fresh air intake unit but when i opened it and measured was no signs of a short circuit, no burned up wires nor damaged PCB boards Etc. Im attaching some pictures and have a few questions.
1. What would cause busses to start arcing like that?
2. Why GE restricted 2 bottom positions not to install anything?
3. Im assuming the panel board with the main etc. needs to be replaced....
Never seen anything like this....
Aidas
p.s ...can not upload images from my Mac ....bummer
1. What would cause busses to start arcing like that?
2. Why GE restricted 2 bottom positions not to install anything?
3. Im assuming the panel board with the main etc. needs to be replaced....
Never seen anything like this....
Aidas
p.s ...can not upload images from my Mac ....bummer
