I supplied 2 Multiplusses to a client in Richards Bay. They have used their own electrician to install it. Today they have send me some pics of the one unit. It was clear that some thing caused this unit to catch fire. At first i suspected a loose connection or too thin wires to be the cause, until we saw the real reason.
Please have a look if you guys can see what caused this fire. Its quite interesting. Afterwards we can also discuss how to prevent something like this happening.
The earth wire caught fire all the insulation is burnt off and it looks like it burnt mostly from AC2 which is the non essential loads.
Common earths across all IN/AC1 and AC2…?
Was it fed by a generator? I’m just guessing but perhaps it had to do with the neutral and earth switch and it ran current through the earth and it was to thin and burnt. Ok will stop guessing now and wait for explanation.
This is very interesting…
From the pics, all I can see is cabling issue : cables too thin for the load that ran through them
Looking forward for investigation report
All the earth’s is all ready internally connected so even if he just earthed the stud on the casing it would have been dlthe same as connecting all together.
Look at the bottom part of the pc board directly below the 4th screw from the left. There is something sticking out from under the pc board. Its the head of a gecko.
In short, no pun intended, a gecko shorted the output to earth. I guess the resistance was not low enough to trip a breaker, but I believe a earth leakage on the input of this inverter might have prevented the fire.
Now if you could have sent us a “smell” file that would have been great!
Does worry me a bit here on the farm… lots of those sort of “critters” and an inverter is a great place to keep warm in winter.
Same here we have tons of gecko and also spiders.
I must make sure there is no (none/zero) copper sticking out on any of my connections in the inverter… 
That’s quite a big fault would be interested to know what size breaker and distance to breaker.
I am currently in a dispute with the installer about this. He used 4mm wire with a 40Amp breaker feeding it. Its about 2 meters from the DB. I will not use a breaker bigger than 32 Amps on 4 mm wire, but that is besides the point. The Gecko will not create a big enough current to trip the breaker, and the client does not have any monitoring on the system so i cant even check the conditions in the last few hours leading up to this point.
I just heard mention of a fire prove mesh that another approved victron installer used to keep gechos out from underneath the PC boards. He also mentioned that Victron has made some improvements to stop this from happening recently.
Thanks @warwickchapman !! I appreciate this input.
I have seen this at builders, actually a brilliant idea
Would the mesh be needed for the top vent as well on the Multiplus 2?
Exactly my thoughts. I have some stainless mesh (for screen doors) will keep big moths out as well…
Prefer the non-conductive kind though 
I guess it wont hurt to install it as well. Rather safe than sorry.
Looking at the Picture and the Victron Manual , it looks like it is the Neutral the got burned and is bridged between AC1 and AC2. Could it be that the sum of current draw between AC1 and AC2 were higher than load capacity of the return neutral. This might explain the “non” trip of the breaker on each circuited as the neutral might not have been protected?
Hang on ALSO the neutral is bridged to AC IN as well , that can’t be good ?
Morning Paul, I think you might be looking at the wrong connection, in these pictures the earth is bridged not the neutrals.
The multi would not work with a shared AC out 1 and AC out 2 neutral. Neither will it switch on with the AC in neutral and the AC out 1 neutral connected together. Unless you chose 1 of 2 very specific grid codes.
