al76 wrote: ↑
Wed, 02 May 2018, 06:08
Also worth noting. Both HRC fuses had blown. Has anyone had this experience? I'm assuming the pip developed a short??
It's not uncommon that when a PIP goes faulty, that it blows its MOSFETs, which fail shorted and present a short circuit across the battery. Surprisingly, this rarely results in battery fuses blowing, though there have been a few reported cases. I believe that this is because the narrow leads to the TO-220 cases tend to act as fuses, clearing the fault current before the main fuses, which are large and have a significant thermal "mass", heat up enough to blow. There is also a 200 A fuse inside the PIP, which also rarely blows. So repair of the older PIP will involve replacing at least half, possibly all the battery-side MOSFETs, and possibly some of their gate resistors and gate driver components. Depending on how the fault happened, there may be other faults, e.g. with the IGBTs that produce the 230 V output, and their gate driver circuitry. When they go, they typically take out a lot of components.
Anyway I have the replacement pip installed (day 2) and its had issues each morning.
I'm concerned that you may still have a wiring fault, which may even have contributed to the first unit blowing up (but this seems unlikely). You mention "connect panels"; presumably you don't use a screwdriver to insert the PV input leads; you must have some sort of switch or breakers that you turn on to connect your solar panels to your PIP. I'm wondering if these might have some sort of bad contact that is possibly temperature sensitive, which is high resistance when cold, and comes good when you switch everything off and on again later in the day when it's warmer. It might be moisture getting in somewhere at night. I think it's worth checking every crimp, wire, and component in the PV and battery parts of your installation. Tug every wire, and so on.
While checking your earlier posts for clues, I note that your older PIP reported firmware versions 72.70 (main) and 04.12 (SCC). Would these have been supplied from the factory, or would you have updated the firmwares at some point?
[ Edit: added "fail shorted and".]
Learning how to patch and repair PIP-4048 inverter-chargers and Elcon chargers.