I have a multiplus 2 with grid tied solar connected on the AC in side. I am now looking to connect another set of PV to the ac1 output. Do I need to change any settings within the multiplus. Many thanks Steve
asked
Solar PV connected to Ac1
If you have ESS assistant loaded you will have too update it to include this PV inverter connected to AC-out.
If you do not use ESS assistant you will have to load "PV inverter support" assistant.
Make sure that the PV inverter connected to AC-out is less powerfull than Multiplus-II you are using.
Some settings in GX will be needed too.
Are you saying the remote PV will trip the RCD feeding the AC-In of the Multi when connected to the its AC-Out but not trip the same RCD when it is connected to the AC-In? In which case it is a complete mystery to me.
If you find the answer please post it here as I am curious to know what it was.
So I did all the necessary all the necessary alterations within the ess to allow for power in from extra solar connected to output 1 on the multiplus, but now when I switch on the extra solar it trips out the mains supply to the multiplus!
Any ideas marekp
Thanks for quick reply
1 & 2 Both solar PVs can input up to 3800 each, although when I tried switching in the second PV they were producing about 250 watts each ( cloudy day here)
3 multiplus is 48/5000/70
4 50 amp
5 the diagram is a bit tricky! I basically have the main PV connected on the grid side of the multi and the PV coming into the multi output 1 is being switched over from a totally different grid connected solar inverter via automatic change over switch. That other grid connection is about 45 metre's away in a shed
When I switch over the change over switch to take the solar off the shed supply and send it to the house multiplus output . It trips out the 50 amp double pole switch that supplies the multiplus from the house grid supply. I don't think it happens straight away maybe 20-30 seconds later .I need to check that tomorrow again. Like I say the current coming into the multiplus output must have been minimal
Thanks Steve
@Sjh126
Ask electrician to check the wiring.
It looks like there is major short somewhere.
To trip 50A breaker on the AC side is not a small thing.
If it trips when generating only ~250W it sounds more like an earth leakage trip than overcurrent. You say it is double pole, are you sure it is just an MCB not an MCBO or RCD?
Maybe there is a spurious N-E link somewhere or an anomaly in the changeover relay setup. What happens if you temporarily hardwire the second PV to the AC-Out?
Thank you for your reply. You're right the double pole that is tripping is an RCD. It's the main switch that supplies power to the multiplus input.
It seems strange that the new set up isn't tripping anything on the output 1 RCD protected consumer unit as this is where the alterations have taken place. Both RCDs have the same tripping values. Thanks Steve
I will try hardwiring the second PV though. The changeover switch looks like a cheap looking thing!
Although I haven't taken the change over switch out of the circuit yet it would appear all that side of things is ok. I can switch over the change over with the remote pv switched off and all is ok . The multiplus's supply trip only trips out when I re introduce the the solar to the multi's AC 1 output circuit.
Sounds like the problem PV inverter may have the neutral wired wrongly and so there is a current imbalance causing the trip. Check it has got the live and neutral wired in the same topology.
Otherwise it may have an earth leakage fault but then as you say why doesn't it trip the other breaker?
If you still can't find the fault please post a wiring diagram here, hand drawn will do.
Maybe in that case something about the inverter wiring is causing a wrong connection between the neutrals or earths of the two different mains supplies.
Good morning.
Well I took all of the automatic changeover switch gear out of the circuit this morning wiring the remote solar inverter directly to the consumer unit on the multiplus output 1.
Again it tripped the main multiplus input RCD
Reconnected the solar back to it's own grid supply and it's working fine, doesn't trip anything in that consumer unit.
The guess I could alter the wiring again and feed the remote solar into the grid side of the multiplus and see what happens but then I lose the solar supply to the ups side if we have a long grid outage.
thanks Steve
Ok so I've temporarily wired the remote solar into the grid side of the multiplus and all is working. Nothing tripping out. It appears the only time the main multiplus supply rcd trips is when I have the remote solar wired into the multiplus output 1, this being what I would ideally like to achieve. I can confirm that I have altered the settings within the ess to except pv input on output 1.
Thanks Steve
Yes but it's not actually connected to the multiplus side of it's rcd so can't trip that. It's connected to the existing house pv consumer unit that in turn is connected via Henley blocks to the existing meter tails.
But it's not tripping that PV consumer unit RCD. I was starting to wonder if there was some sort of fault in the remote solars armoured cable that I'm using to connect it back to the multiplus output 1. But everything is fine running through the house solar consumer unit. But trips the multi's ac in RCD if I connect to the multiplus output consumer unit!
What happens if you connect it
via the RCD that feeds the AC-In to the Multiplus? I thought you had already tried that, but on re-reading the posting above it appears that you have not. Maybe this RCD is more sensitive than the other. You could also try swapping the two RCDs if they are mechanically and electrically the same to rule this out.
Still not clear about the various connection regimes, can you please post a diagram?
I am very curious for a diagram as well on this one.
Not related to your RCD problem, the inverter that you wired to AC-out, it needs to be throttled in case your grid is out and the batteries are full, in order not to cause serious damage to system. Considering it was grid-tied before, is it now configured as such? I believe the country code should be set to microgrid
It sounds to me, if I understood correctly, that both parts have seperate grid feeds and meters. If I understood correctly, it's likely that the two different grid feeds are on different phases making it imposible to sincronise apart from jumping from 230V to 400V. Could this be the case? Two seperate grid feeds?
It sounds to me like you're providing a parallel neutral or earth path bypassing the RCD so it will trip as it'll see an imbalance, you can't have AC out 1 connected to AC in with them both live..
The answer might be late but have you tried to change the RCB for a MCB worked for me
