- Joined
- 27 Jan 2008
- Messages
- 27,686
- Reaction score
- 3,353
- Location
- Llanfair Caereinion, Nr Welshpool
- Country
I will start it off with a tower crane at the building of T5 which dropped it's load. As one would expect the head man grounded all tower cranes of that manufacturer until the manufacturer had worked out how it happened.
So we got a call that the generator (500 kVA CAT) was faulty, we attended and when dropping the load the generator did speed up, however not to over 100 Hz which the frequency meter was reporting.
My boss and I both said it had to be something with a diode in it, and most likely was one of the inverters, can't remember what the faulty inverter was for, but it was not the one which dropped the hook. Disconnecting one inverter at a time the faulty one was identified and changed and the fault appeared to go, my boss and I were not satisfied however other events over took this and we never found what was done to stop a repeat.
However one inverter causing another inverter to fail is not something you see with mains supply, there is enough to damp down any odd injection due to the fault, it was only because we were using generators that we had the problem.
So I am inviting people to give other times when some thing unexpected caused a fault.
So we got a call that the generator (500 kVA CAT) was faulty, we attended and when dropping the load the generator did speed up, however not to over 100 Hz which the frequency meter was reporting.
My boss and I both said it had to be something with a diode in it, and most likely was one of the inverters, can't remember what the faulty inverter was for, but it was not the one which dropped the hook. Disconnecting one inverter at a time the faulty one was identified and changed and the fault appeared to go, my boss and I were not satisfied however other events over took this and we never found what was done to stop a repeat.
However one inverter causing another inverter to fail is not something you see with mains supply, there is enough to damp down any odd injection due to the fault, it was only because we were using generators that we had the problem.
So I am inviting people to give other times when some thing unexpected caused a fault.
