justin288 wrote: ↑Tue, 20 Oct 2020, 07:52
Last weekend, I installed the 2nd one in parallel with the first.
I assume you followed the manual (either the inverter manual, if it has a paralleling section), or the parallel guide. Though I don't see separate isolating breakers for each inverter's output (maybe they're just not in the photo, or I missed them). So you would have set each inverter to PAL mode (setting 28),
before paralleling the outputs.
1. The F09 appeared after Paralleling it with the previously installed 5048MK. The F09 kept reappearing after restarting even in single mode.
Yikes. That sounds like the inverter proper became damaged by paralleling two inverters when they aren't synchronised (either by having their output modes set to PAL or by having AC-in connected to both).
3. I cleaned the Main Board soldering with a tootbrush (copied from one SA forum) and reinstalled the main board and used the battery to turn on, no error codes.
I think either you dodged a bullet there, or the other inverter suffered the damage, and the fault transferred to all of them. I'm not clear on which inverter(s) showed the fault code.
4. Do you have any idea what will cause the error code?
Fault code 09 is caused by a failure to pre-charge the bus capacitors at start-up. In other words, a small power supply was turned on to charge up the capacitors, and they did not reach a certain voltage within a certain time. Often, this means that there is a short across the bus, usually due to a pair of IGBTs failing short circuit.
4. I see members here used to parallel operations, Kindly give detailed steps to parallel both inverters. The Manual is not clear.
First, wire the inverters such that they both have their own isolating breakers. Start by isolating (disconnecting) both outputs. Ensure that AC-in is present. Turn off an inverter, change setting 28 to PAL, then turn it on. Do the same to the other inverter. At this point, I always get a multimeter and measure the difference between outputs (one multimeter probe to each active output), and make sure that there is less than about 20 VAC. Now repeat with AC-in disconnected. If they stay synchronised (the voltage between them stays low), then this must be happening via the CAN bus (the grey "paralleling' cables). Now you can un-isolate the first inverter, noting the load. Finally, unisolate the second inverter, and check that the load is roughly divided between the two inverters. The loads should differ by no more than about 20 W.
More so, after paralleling, where is the setting for charging voltage and current done (Master, Slave or both inverters)?
Most settings, including the charging
voltages, are set on either/both (changing one should change the setting in the other automatically). However, charging
current settings are individual to each inverter (you might have more or better PV connected to one, for example). So set these up individually. Note that the maximum total charging current for the battery will be the sum of the maximum total charge current settings in the paralleled inverters. So for example you might have 30 A on one and 40 A on the other, resulting in a maximum total charge current of 70 A (good for two US3000s, for example, which can take 37 A each, so 80 A is too high and 60 A is needlessly low).
6. The Serial Port on both inverters for connection to watchpower (laptop) are not working. I used an rs232 to usb adapter that works for the old 24v Mpp solar inverter.
The Firmware on both 5048Mk inverters are:
U1 71.90
I can't recall if 71.90 handles paralleled MKs or not; I think it does. There was a problem with earlier MK firmwares, probably about 71.80 or even 71.86. But that should be fixed now. 71.93 and 71.94 are available, but they don't contain each other's fixes, so there doesn't seem to be a good update to 71.90 at present. I don't use Watchpower myself, so I can't think of anything to suggest.
U4 00.00
This probably reported as zero because it was night time. During the day, PV powers the solar charge controller, and it should report its version.
The format is [
img]
url_of_image[
/img], and you have to fish out the image URL from the surrounding page. Or you can drag a file name from a file explorer into the editor window. They will then look like this:
Edit: BTW, is 181V real? I assume your mains is nominally 220 V, but that's still 18% low.