Solar PV Hints, Tips & Troubleshooting

https://www.boards.ie/discussion/comment/122881649#Comment_122881649

When you say that it has never worked properly, what does this mean?

Regarding the relay, are you sure it switches the neutral? It might be a relay to connect your neutral to earth on grid failure. Pictures would help here. Very difficult to know without seeing how it's wired.

Borax2709

https://www.boards.ie/discussion/comment/122873677#Comment_122873677

by way of update - changed DOD to be 89% instead of 90% and have had no alarms / everything behaving as normal.

Grand.

brownep

Thanks for your interest in my problem. The change over switch is two pole with three positions. Grid on, all off and battery backup. The switch has live and neutral feed from the grid to my home loads. But also there is a link from the incoming live to the grid failure relay via a controller module. This means that when turned to the off position or Backup position the live feed is still going to the controller and grid fail relay. Neutral does switch off. When I switch to the backup position, with all my sockets off and only lights left to be supplied I sometimes get a blink of light but the inverter always trips. The last time my installer looked at it he felt that the grid fail relay could be the problem but he went off to consult someone and hasn't returned.

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graememk

https://www.boards.ie/discussion/comment/122885287#Comment_122885287

My Dad has a solis, and a full changeover.
In his mini CU beside the inverter there is a AC Backup MCB., It is interlinked with a NC contactor that interrupts the Inverter Grid AC in when energised.

Change over sequence is
Turn everthing off in main Consumer unit
switch changeover switch to Off.
beside inverter, turn on the Backup MCB - this is only ever turned on when you want to use the backup.
changeover to Backup
Slowly turn things on so not over load the inverter.

Something to try is to turn off the inverter RCBO so not to feed the inverter its own power (and make it think the grid is back)

But without knowing what the mains fail relay does, we wont be any wiser

championc

Might be worth asking the installer if there is an earth / neutral bond when in backup, since you say the neutral is definitely disconnected.

https://www.boards.ie/discussion/comment/122885287#Comment_122885287

You say the inverter trips, do you get an error code?

10-10-20

https://www.boards.ie/discussion/comment/122885287#Comment_122885287

"When I switch to the backup position, with all my sockets off and only lights left to be supplied I sometimes get a blink of light but the inverter always trips. The last time my installer looked at it he felt that the grid fail relay could be the problem but he went off to consult someone and hasn't returned. "

As far as I can see the rated "AC backup" on those is 5kW, but what it sounds like is that the instantaneous starting current is tripping the inverter. That instantaneous starting current is what happens when devices are powered on after being fully drained - they each pull a large enough current as they fill up their capacitors and what's happening is that you're powering on all of these devices at the same time. You can't bring a whole house online like that - you need to stage it by only bringing on a subset of devices and possibly even unplugging things like PC's and phone chargers while you start-up.

brownep

https://www.boards.ie/discussion/comment/122885325#Comment_122885325

Thanks for the advice. I will try your ideas in daylight. Probably Saturday. It's not ideal that the inverter is in my attic and the consumer panel is two floors down. With the strange live loop across the changeover switch I suspect there might be an issue of two supplies meeting. The grid live and the inverter output. Any clues to what that loop is supposed to do? The error on the inverter is simply "over current". With all my power outlets off that is unlikely to be related to home consumption.

https://www.boards.ie/discussion/comment/122885851#Comment_122885851

And as I said in my previous post, this happens with everything except lights off. And all my lights are LEDs.

brownep

I just want to clarify that the backup outlet socket on the inverter is not being used. That would require a separate supply loop to essential devices, totally outside the normal house supply. Things like life support appliances.

bod71

Hi, I have a solis 3.6 inverter and 2 by 2.4kw Pylontech batteries that are 4 years old. I’m having issues with batteries charging and discharging @50% and getting alarms on inverter for about 3 weeks now.Could there be an issue with 1of my batteries.

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graememk

https://www.boards.ie/discussion/comment/122890725#Comment_122890725

Very possibly.

When fully charged are bothe batteries showing full?

bod71

Yes, both batteries show full, but im definitely not getting 4 kw,and they drain a lot more quickly. This is them charging now

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bod71

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yesterday shows full.

10-10-20

https://www.boards.ie/discussion/comment/122891213#Comment_122891213

Not sure it matters… but are the addresses all set the same? Can't tell from the photo.

bod71

Sorry, what are the addresses ?

10-10-20

https://www.boards.ie/discussion/comment/122891473#Comment_122891473

The little switches under ADD which provide the BMC address/ID.

bod71

Yeah both the same

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10-10-20

https://www.boards.ie/discussion/comment/122891624#Comment_122891624

@graememk - is that an issue or does the BMC have it's own internal addressing?

graememk

https://www.boards.ie/discussion/comment/122891652#Comment_122891652

Don't know enough about pylontechs to know.

But I'd air on the side that it shouldn't matter as it was working and getting worse.

Id be contacting pylontech support.

Muahahaha

Trying to advise a friend on their solar install in the new year. Their front roof is due west facing with the back due east. The system will feed back to the grid for unused power, there is no battery. Is there an optimum way to do it, the option being 4.4kwp of panels on the west facing roof or half and half to east and west. What are the considerations here, is there any data to show you'll generate more power from west facing only in the summer evenings vs taking advantage of the morning sun?

Also I seem to remember an online tool that can roughly calculate expected solar generation by your location. Can someone kindly link it so I can see what they might generate.

con747

https://www.boards.ie/discussion/comment/122893350#Comment_122893350

https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html

Muahahaha

https://www.boards.ie/discussion/comment/122893382#Comment_122893382

thanks for that Con. Do you have any insight into if going west only or a combination of east and west is the best solution? And is there a % loss overall vis a vis having a south facing roof?

con747

https://www.boards.ie/discussion/comment/122893446#Comment_122893446

I have east/south/west and find it works good for my needs. It will all depend on the usage times I suppose though.

graememk

https://www.boards.ie/discussion/comment/122893446#Comment_122893446

Generally you got to work with what you've got. South is the best all year production,

If its in the budget, Fill both roofs! in the summer East will give you more power in the early morning, West will give you more power than the afternoon/evening. I dont think anyone here has come back and said, "I got too many panels"

LowPowerMode

https://www.boards.ie/discussion/comment/122846190#Comment_122846190

Thanks again Liam2021, took a while but looks like I'm sorted now as well. I had made contact with Dyness before I saw your post as assumed it was the battery rather that the inverter so not sure if I would have got sorted without seeing your post or would have taken a lot longer.

Solis did a few updates to mine and at one stage said that I had the latest firmware but luckily you had posted that screenshot that showed the additional flexibility on the change/discharge settings and I didn't have that on mine yet so queried that and got another inverter update that added that and looks to be working fine since then.

Liam2021

https://www.boards.ie/discussion/comment/122900649#Comment_122900649

Great glad to be of help

The devils

Any recommendations please

Replace solis 6kw hybrid invertor with another one ? Not sure what you guys would suggest please??

Tks and happy Christmas 🎄

Jonathan

https://www.boards.ie/discussion/comment/122980610#Comment_122980610

Why are you replacing it? Did it die? Any warranty left?

The devils

No all good and working fine, however

Max amp output for charging batteries 65 to 70 amps...

I'd like to know if anyone here has upgraded and or sold/replaced there inverter

👍👍

championc

Buy a 3kW rectifier. Means you can charge with an extra 3kW without worrying about the NC6 limit

Emerson R48-3000e3 Communication Switching Power Supply Module 48V

https://a.aliexpress.com/_Ey0eFJa