Arc faults

[asdex]

Hi, I have had a number of arc faults recently for no apparent reason. All connections, wiring and components are ok as far as I can tell. Should I need to check the AC side of my system or just the PV- controller-batteries?
My battery bank negative is connected to earth and the controller, inverter, and wind generator are all earthed (connected to the battery bank negative).
Also should there be some sort of indication or warning noise if there is a fault like the arc fault? I have to keep monitoring the controller regularly to see if its tripped. I have audio on and volume up although I don't remember seeing a speaker in the chassic last time I opened it up.
Thanks,

[boB]

How often do you see an arc fault trip ?

I'm thinking you might temporarily disconnect large inverter loads for just a while to
see if the arc fault stop.   OR, maybe, turn ON and OFF large loads to see if it CAUSES
more arc fault trips while doing that ?  Things with motors, mainly....

Have you tried raising the arc fault sensitivity and time number in the TWEAKS menus ?
That is, if it is not already all the way up....

The speaker itself is in the MNGP remote, on the left side, behind the little holes.

Thanks,
boB

[ClassicCrazy]

The speaker is inside the MNGP - pop that open and make sure the connector for it is plugged in to the board in there.
I have no experience with Arc Faults - you can always disable it via MNGP or Local Status App if you want to . Just checked mine and I see I have Arc Fault disabled on one of my Classics - so maybe had some issues with it in the past . There are also sensitivity settings so you can adjust it .

Larry

[asdex]

Hi, thanks for your replies.
I was able to take the front panel off to check the speaker and found it not connected.
I also noticed a "remove" sticker on the battery and removed it. What is the battery for? Its been like that for a couple of years now.
The arc fault occurs half a dozen or so times a day. We have a fridge and freezer off the inverter but these have always been going and the arc faults have just started recently. In the manual it says the arc fault "detects problems in the PV side of the system" so didn't think the AC side is monitored.
Can you tell me how the arc fault detection works? Does it monitor current flow to earth?
I have set the time setting to the longest and sensitivity to the lowest setting. I'll see how this goes tomorrow.
I notice when cycling the power to change the arc fault settings the battery SOC goes to 90% even though it was 100%. Is this normal?
Thanks,

[ClassicCrazy]

The battery in the MNGP is the backup battery for the time so it holds it if  you disconnect MNGP -- which means I should probably check mine since it reset the time back to 2000 last night when I unplugged it to look inside when responding to you .

Larry

[WillEert]

I recently got an arc fault alarm after a few years of using my system. Initially I disabled the alarm but started checking the system over to see what had caused it to go off. I found partially melted wiring on the negative bus in the DC Magnum MPDH panel. It appears as though the factory connection to the MPDH panel may never have been as tight as it should have been and with the greater loads I have been running with car charging, the connection started arcing and caused the wiring to heat up. Scarey. Magnum sent me a new bus and mounts and I upgraded the wire from AWG 2 to 2/0. Fine now with no heating up. I am very pleased with the arc fault system in the Midnite Classic. Likely saved me from a real nasty situation that was developing.

Will

[asdex]

Thanks very much. I have checked all the DC connections and just checked to the inverter and all is ok. I hhaven't had any further arc faults since decreasing the sensitivity and increasing the time.
I'll see how this goes now.
Cheers,

[australsolarier]

two out of four midnite classic 150's i had to lower the sensitivity too. one right from the beginning, the second took a couple of months to arc fault disengage. they are going alright now.
and yes, it made me check all the connections as well, but nothing found