I have bought a second multiplus 48/5000 to run parallel to my first one as the first one does work pretty hard on sunny days.
Anyway, the second one has a slightly different model number to the first, just the last digit being different : PMP482505010 and PMP482505012 so obviously my first question is will these will work together ? The docs on parallelling say they should be “identical”.
Second question is about AC wiring, maybe I should create a separate thread about that (let me know and I will edit) anyway, the ACin is supplied via a 10mm copper cable as it’s fairly long and a fairly large current passes through sometimes but the docs say for parallel systems to keep AC cable size to a minimum and some websites even say to “undersize” the cable which is, to me, a bit daft although I understand the reasons behind it, but anyway I can’t undersize the ACin cable. The ACout1 goes back to the house loads in 6mm which again I can’t reduce in size and still stay functional.
What could I do to ensure a balanced system ? Measure currents when all is up and running and add length to one or other of the cables to get equal currents ?
Thanks in advance.
What are the first 4 digits, after the two letters, in the serial number?
Typically when older than a year or more, it isn’t a good idea to pair them, but a while back there were some hardware changes which mean that those generations don’t always play nicely together.
It should work, those are post a major change that I am aware of. There obviously is a difference, and wear on one will also have an effect.
Ultimately this will affect symmetry, but perfect symmetry doesn’t exist.
Make the new one master and following the wiring guidance exactly.
You will need to check them under load with a clamp meter.
You can also use the flow I posted in modifications to display asymmetry.
I switched on the second MPII this morning and it shut down the system with a V.E.bus error firmware incompatibility. I know I had to update both firmwares but I thought they would obviously have to be switched on to do that. I suppose the method to avoid the error is to switch on MPII A only and update that, then switch off A and switch on B and update that, then switch on both ?
Also, the Current transformer I have connected to MPII A (which now will be slave) should I swap it to MPII B (master) and leave the shunt out of MPII A or put the shunt in with “internal” mode ?
Best is to carefully step through the parallel setup docs, do the video training on this as well. It becomes clear.
I would reflash the lot with veflash, then use the quickconfigure tools to parallel them. Master should have any “sensor” cabling attached to it.
Push the same config to both, anything not needed for a secondary unit will be ignored or greyed out.
Yes i’ve read the docs but the training videos I have not seen.
I don’t have an MK3 adaptor so I’ve only got V.E.config. Can the parallelling be done with that or not ?
At the moment I am rewiring my fusebox slightly to allow me to reinstall the ESS assistant ! (it cuts the whole house and therefore LAN when it installs the ESS so install keeps failing). Once I’ve got that sorted I will get back to paralleling and watch the vids.
You will need a mk3 and the full set of utils which will call veconfigure when required.
If the proverbial hits the fan, a mk3 is vital as often veflash is needed.
Thanks for that, I didn’t realise the professional account was also for the end-user. There looks like there’s some good stuff there, hopefully all the answers I need.
So is the MK3 absolutely essentiel for the parallel config ? If so, I will have to postpone my project. The second Multi is all wired up but unusable at the moment.
For 3-phase and parallel, you will need a dongle.
There are some great training vids from the honourable Mr Stewart, just wish more people watched them!
OK, thanks for that info. I will get one ordered.
I’m in a bit of a pickle at the moment as since the fw update the multi is behaving badly and just wants to charge the batteries and nothing else. I thought it was the loss of ESS assistant but after rewiring a bit to allow the upload of the rvsc file the system still charges only. I have cut the grid and the multi starts inverting immediately but as soon as I switch the grid back on we are back to charging only. The ESS shows now in remote console settings>ESS, grid setpoint is still 50w as before the fw update…but I can’t see what’s wrong with the settings. Any ideas ? I need to get this working again before I retry with the parallel set up…
