Quattro on fire, but luckily the house is still standing!
I made a mistake by using a string of PV panels that caused the voltage to exceed the recommended level. It worked fine for about six months, but then the outside temperature dropped, and the PV voltage rose to a level where the MPPT failed. Instead of switching off to protect the battery and the rest of the system, the MPPT continued to feed the DC side of my system, but at a much higher voltage. The result: a Quattro on fire, two damaged MPPTs, and four damaged Pylontech batteries. The total damage is around 10k euros.
I believe that all the advertised security mechanisms built into the Victron system failed dramatically. However, Victron claims that I caused the problem by exposing the system to too high a voltage, which led to the safety measures failing.
Who do you think is at fault in this case?
I think this is between you and your supplier.
On the internet there will be a million opinions of varying quality.
We do not have the ability to review your system, how it was wired, setup etc, so no one can offer an informed opinion, beyond that properly configured and installed systems do not catch fire.
These are systems designed to be installed by trained professionals, and as a community, most of the issues that appear here are from people who have bitten off more than they can chew, often with little research and training.
Like our guidelines say, there are things that are just beyond the communities scope, Assigning blame would be one of them.
There is a reason why even basic switchgear and fusing has voltage/amp ratings. And it is this… Fire. Fire is often caused by arcing. And arc gaps and components are designed by voltage and amps expected in a circuit.
There comes a point where is does not matter and the power bridges things and makes its own way to destination especially DC
2 posts were split to a new topic: Designing a system for safety and fire prevention
It’s not that I’m trying to blame anyone on this forum; rather, I need to understand why the built-in safety measures didn’t work and what the chances are of this happening again. The manufacturer is aware that overvoltage can occur for various reasons. There are error codes and interventions described in the user manual. In my case, error codes #40 (PV internal failure) and #86 (PV input shutdown) were triggered, but none of the interventions took place. This occurred at a registered 146 volts, which is below the 150V threshold, so I don’t understand why it happened.
Never, ever exceed the PV Maximum Input Voltage. When sizing a system, you have to leave room for cold temperatures and cloud effect. The Victron MPPT Calculator will account for cold temperatures if you provide them.
With regard to your error codes, maybe those are just the last codes that could be stored before the system was fried. Something much worse than 146 volts probably happened. My experience is that you have to work pretty hard to kill Victron components. I’ve done it, but it was my own error.
What was the over current protection between the solar charge controller(s) and the rest of the system? OCP won’t protect from over voltage. If the solar charge controller allowed PV voltage straight through, then the amps were probably low so the OCP didn’t catch it.