Guru
Joined: 13/10/2014
Location: AustraliaPosts: 1858
| Posted: 06:40am 15 Mar 2025 |
High current draw then Short on Inverter AC line.
I came back to the house after a morning walk to find no power (off grid), the Inverter was averaging around 6kW when I left.
Looking back at the LOG, an Unknown fault on the AC wiring had caused the DC input to run over 17Kw, over 30kW peak, into the Inverter for at least 6 minutes.
I was glad to find the Inverter was still happily idling with no error and showing 243VAC output, the Inverter AC output runs to a double pole DZ47-C63 circuit breaker, and this had tripped after around 6 minutes running time at high AC current.
I switched the 63A circuit breaker back on and it instantly tripped again.
This time the Inverter also tripped with an over-current fault indicated on the LCD.
Two DC input current trip LEDs were ON, one on each DC input feeding two Power boards, but no AC current trip, Inverter AC current trip is set at 73A from memory.
I reset each DC trip indicator/button and pressed master reset - leaving the 63A AC circuit breaker off.
The Inverter powered up perfectly, tough little bugger.
I switched over to Mains power and the changeover switch visibly arched on connect, normally there is NO visible ARC, Mains power tripped another breaker as it switched.
It appears there might be a short or arching across a socket or fault in some powered on equipment?
I checked external power points for water ingress etc, powered everything off and switched the Mains AC breaker back on, this time nothing tripped, finally powering everything back on without a problem.
Switched from Mains AC back to Inverter AC power and everything is running perfectly.
It's possible I had a Gecko in the Inverter-Air-Con, happened before, but the AIR-CON powered up fine this time, or the third time that AC was switched on, it might have cleared a short of some kind?
Recap, a high current draw that was not a complete short caused a 63A AC breaker from the Inverter to trip, the fault on the AC line (now a short) instantly tripped the Inverters 63A AC breaker when I reset it, this caused the Inverters DC input protection to trip, the Input protection is designed to trip at 850A Peak DC input, and it did that without fazing the Inverter at all.
We had the Cyclone go through here a week ago, but I did not find any sign of water ingress after it, and Inverter has been running perfectly for a week of fine hot sunny days ?
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Edited 2025-03-15 16:46 by KeepIS