I have a parallel 6000xp setup that had been running fine for about a month suddenly go (Flash Bang). Unit 1 had been running for 6 months as a single inverter, but I needed slightly more power and having a second inverter for backup seemed logical so unit 2 was installed. I happened to be nearby and since I had problems with unit2 dongle communications going offline at that time and I was trying to resolve this, I immediately cut all breakers and power including parallel sync cables to unit 2 thinking this was the problem unit.
Unit 1 continued to provide power, but it was working in grid bypass mode only. I left the unit running and went to get some troubleshooting tools and came back 5 minutes later hearing more flash bangs from unit 1 and seeing smoke curling out of the fans. At this point unit 1 was also taken completely off line and troubleshooting began. Unit 1 was effectively dead. It would only provide power in grid bypass mode. Solar MPPT seemed to be dead also.
Unit 2 came back online and started providing power without problem, however the dongle communication problems persisted. Sig Solar was contacted and within a few hours I was in contact with Chris Money Sig Solar Tech Solutions. I provided the usual exhaustive list of site survey, pictures, pictures and more pictures to help figure out the issue.
Chris Money Sig Solar claims that my 6000xp went Flash Bang due to multiple landings. What this means is that rather than use a utility combiner box, and a load combiner box, I had the multiple wires joined in the breaker, inside unit2 of the 6000xp. Inside the breaker connection we had a 4ga heading to the load and a 10ga heading over to unit 1. Sig Solar replaced the unit under a Defective Product - First Strike Policy, which is now on the wall but not yet hooked up.. I want to make sure that I don't smoke a second one.
Wiring image of multiple landing in Unit2 (not the failed unit)
There are many different ways to combine wires. You can use a combiner box, you can use a collar crimp, and you can be lazy like I was and just combine both wires in the bottom of the breaker. I open myelf up to criticism on this now. I really don't have room for a combiner box. How should I combine the wires?
I am also suspicious that something else was wrong as I had trouble getting the parallel settings to take and reversing the parallel cables seemed to resolve the issue. Is is really multiple landings that killed unit 1 or could it possibly be failed parallel sync cabling?
Unit 1 continued to provide power, but it was working in grid bypass mode only. I left the unit running and went to get some troubleshooting tools and came back 5 minutes later hearing more flash bangs from unit 1 and seeing smoke curling out of the fans. At this point unit 1 was also taken completely off line and troubleshooting began. Unit 1 was effectively dead. It would only provide power in grid bypass mode. Solar MPPT seemed to be dead also.
Unit 2 came back online and started providing power without problem, however the dongle communication problems persisted. Sig Solar was contacted and within a few hours I was in contact with Chris Money Sig Solar Tech Solutions. I provided the usual exhaustive list of site survey, pictures, pictures and more pictures to help figure out the issue.
Chris Money Sig Solar claims that my 6000xp went Flash Bang due to multiple landings. What this means is that rather than use a utility combiner box, and a load combiner box, I had the multiple wires joined in the breaker, inside unit2 of the 6000xp. Inside the breaker connection we had a 4ga heading to the load and a 10ga heading over to unit 1. Sig Solar replaced the unit under a Defective Product - First Strike Policy, which is now on the wall but not yet hooked up.. I want to make sure that I don't smoke a second one.
Wiring image of multiple landing in Unit2 (not the failed unit)
There are many different ways to combine wires. You can use a combiner box, you can use a collar crimp, and you can be lazy like I was and just combine both wires in the bottom of the breaker. I open myelf up to criticism on this now. I really don't have room for a combiner box. How should I combine the wires?
I am also suspicious that something else was wrong as I had trouble getting the parallel settings to take and reversing the parallel cables seemed to resolve the issue. Is is really multiple landings that killed unit 1 or could it possibly be failed parallel sync cabling?
