question

conceptura avatar image
conceptura asked

Defective Unit - fire hasard

Hi all. A friend of mine bought 3KW multiplus and hooked it up to some power queen lithium batteries fed from a power queen controller. For no apparent reason and without warning the unit (victron) caught fire and nearly burned the house down. The supplier changed the unit out and sent a new one to replace it..no questions asked. Happy with that he reconnected the new one but that unit started smoking and so my friend disconnected it from the batteries and started the after sales process again. This time the supplier refused to replace it, blaming the problem on a number of things such as over voltage and wrong cabling. The batteries were cabled in parallel 12V on a 12V unit and the measured voltage was around the 13.5 mark when the problem ocurred. The battery cables were very heavy duty ones, the type used for jump starting a car. There was no load on the inverter above about 50W. The inverter was not connected at all to the controller and the only connection it had was from the batteries on the input side and a small load on the output side.

Any ideas what can be wrong?

Thanks.

fire
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

7 Answers
Duivert NL avatar image
Duivert NL answered ·

Well there must be something seriously wrong with wiring/fusing/voltage if you burn 2 multiplusses… they dont burn just like that

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

nickdb avatar image
nickdb answered ·

Does your friend actually have any electrical experience or victron knowledge?

This sounds like something seriously off in the installation.

Victron gear is tough. If you've smoked two, there is a bigger problem somewhere else.


2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

conceptura avatar image
conceptura answered ·

Thanks for your feedback. I have sucessfully installed 3 systems with these victron units: exaclty the same configuration as for my friend only with lead acid batteries and an EPEVER controller. I'm looking for suggestions and ideas as to what could have gone wrong. Many thanks.

2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

nickdb avatar image nickdb ♦♦ commented ·

Impossible to tell remotely with no access to the installation, nor its configuration. Suggest you follow the official support process as per the community guidelines.

Victron takes reports like this very seriously, I would keep an eye on your email in case someone reaches out, as this was flagged by the moderation team.

0 Likes 0 ·
conceptura avatar image conceptura nickdb ♦♦ commented ·
Maybe Victron could have a word with the reseller in Germany. I do thnk it would makes sense for Victorn to get the unit back and do diagnostics but that's up to the reseller. A third party advisory consultant has suggested to my friend that he get another Victron unit (with integrated MPTT and breakers) but this sounds like madness given that nobody seems to be able to provide a root cause as yet. I also take this case very seriously so good to hear that victron does too. Thanks for any help you can give.
0 Likes 0 ·
wilm avatar image
wilm answered ·

PowerQueen controlers are by default set to 24V.

So what happens:
Your batteries do see 24V+ and the BMS will switch off (OVP).
Your Multiplus sees 24V+ and will burn, as there is twice the voltage.

This happens often when using non compatible, or mis-configured items.

Sorry for your friend, but a house-made-problem.

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

conceptura avatar image conceptura commented ·
Thanks for your insight and sorry for the late reply. The batteries were charged to between 13 and 14V so they did not see the 24V you refer to. Also the Multiplus could only see this voltage (13-14V) so I don't see how your point applies to this case. thanks for taking the time to answer in any case.
0 Likes 0 ·
vicens avatar image
vicens answered ·

Que parte del inversor se ha quemado? Pon alguna foto de la instalacion y el quemado. Esquema.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

conceptura avatar image
conceptura answered ·

Hola Caballero, siento el retraso en contestar. Desafordunademente el multiplus esta ja en case del vendador aleman quien no quiere reconcer el problema. No puedo entonces enviar fotos.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

dc-marine avatar image
dc-marine answered ·

What about leave steel hardware between the cable lugs and the connection bus on the multi ? It's easy to do this mistake if you're not paying attention, simply removing the nut and leaving the flat washer and/or the lockwasher in place before connecting the cable. This will lead to a fire real quick once there's enough current being draw. I see it quite often in the marine world where the same mistake were made on fuse holders and busbars, along with loose connections and bad crimps on the lugs. With no pictures of the connections there's no forensic investigation that can be done to help you understand what happened.

3 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

conceptura avatar image conceptura commented ·
Thanks for your suggestion and sorry for late reply. I'm not sure what you mean by 'leave steel hardware' as that is open to several interpretations but I can say that proper battery lugs with very thick gage cable (good quality jump lead type) were used and tighly screwed in place with no loose connections at all. I have a similar setup on three other systems (only difference being they are using lead-acid and not lithium batteries) and have no issues on any of these systems.
0 Likes 0 ·
dc-marine avatar image dc-marine conceptura commented ·
Sorry about the typo, should have read “steel hardware between the connection point and the cable lug”, such as a steel washer between the cable lug and connection point.
0 Likes 0 ·
Matthias Lange - DE avatar image Matthias Lange - DE ♦ dc-marine commented ·
It's not good to have the washer under the lug but that shouldn't cause a smoking unit immediately.
0 Likes 0 ·

Related Resources

Additional resources still need to be added for this topic