Victron 10000 va inverter blew up

yrtrnc

The dThe damage is concentrated in this area on top of the communication cables. There was a burnt smell and the overload led was on when i checked the unit. What caused this error? We don't have high loads, only a kettle 1800 w was on at the time.

mcgivor

Lightning would be a first guess, any electrical storms present when this occured? 

yrtrnc

No, no lightning storms! The only clue I have is that a 32 amp rcbo tripped once before this happened. The 32 amp rcbo is connected to a 2000 w grill  and a 1800 w kettle. 

yrtrnc

There has been drilling going on lately, could it be that one of the wires was drilled through and line and neutral is in contact? Would this damage the inverter like this? There are no signs of high load spikes in the log files! 

mike95490

yrtrnc said:

There has been drilling going on lately, could it be that one of the wires was drilled through and line and neutral is in contact? Would this damage the inverter like this? There are no signs of high load spikes in the log files! 

Someone was drilling holes in the inverter case ?  No warranty for you.
Dead short line - neutral inside the case has no OCP . 
10Kw inverter, I hope it was a 48V unit.   Something had to have gone very badly wrong  to blow up like that

>  The 32 amp rcbo is connected to a 2000 w grill  and a 1800 w kettle. 
What is a rcbo ?   2000 grill and 1800 kettle are not insignificant loads.  Together, they would draw about 80A from a 48 v battery, or about 40A each.  Either of those is over 32A

yrtrnc

No, no one was drilling anywhere near the inverter. The drilling was on the house walls, I was just considering if they hit a wire. But how would that cause a fault. The rcbo in the house tripped once, I put it back on. Everything seemed fine then later it blew. If there was a fault with the circuit why didn't the rcbo trip again.

yrtrnc

The drilling was a week ago BTW. 

Vic

Perhaps,  a loose connection on the AC out,  or the DC into the inverter?

Most high quality inverters,   used in off-grid systems,   will shut down within milliseconds,  when the AC output is dead shorted  --  long before almost any circuit breaker can trip (generally).

Good luck,   Vic

mcgivor

Hard to tell from the image but it could have been a capacitor failure, the residual current circuit breaker, RCBO, which is a ground fault main breaker for the benifit of those who aren't familiar with the term, would have tripped on any external short.

How old is the inverter, could you post a wider image which would show where exactly the fault occured? 

yrtrnc

On top of the communications cables. The damage is to the wires coming from the transformer and connecting to a board with a bunch of mpx x2 capacitors and a couple of fuses. The inverter has only been used for 6 months. Also, no loose connections. 

mike95490

That was a pretty hefty burst of current thru that wire, to totally vaporize the insulation off it .   Whatever caused it, it was bad.

yrtrnc

I checked the circuits in the house one by one. And found continuity between line and neutral on one of the circuits. I traced it to an ip rated socket on the outside wall. Looks like Hager rcbos are shit after all. But how a short circuit within the property would cause an inverter to blow up is beyond me. Any thoughts? 

mcgivor

A short in a branch circuit would likely cause failure in the smallest conductors if the overcurrent is sized greater than it current carrying capacity of the conductors downstream of the RCBO, likely smaller than the one in the image. Furthermore inverters tend to self protect against short circuit faster than a breaker can react due to the trip curve criteria, thus the damage may be unrelated to the RCBO's performance.

There is a difference between a dead short and a ground leakage, a dead short would be the same as a load, both live and neutral carrying equal current, a leakage, or residual current is the differential between the current carried in the live and neutral conductors. Therefore in a short condition the rated amp capacity of the device would be relied upon as an overcurrent protection device, there would be no imbalances to cause a leakage trip.

Regardless the best course of action would be to contact the dealer to initiate an RMA (return merchandise authorisation) for a warranty claim,  it could have been something simple as a bad crimp which caused overheating, something that is possible even with the best products on the market. My opinion, for what it's worth, is its unlikely the fault was caused by a short circuit but the manufacturer may see things differently, your call on the information provided.

MichaelK

Hager Residual Current Circuit Breaker with Overcurrent Protection devices (RCBOs) provide MCB overload protection and RCD earth leakage protection (protects against electrical shocks by direct or indirect contact). A range of sensitivities and current ratings are available for use in residential, commercial and industrial applications.