MPP solar

[Busman]

One for T1
I think you have used this product in the past ? If so, any good ? Thinking of adding a dedicated 3 phase system using bus battery when we are here, would use a small Lith battery when not. Interested in your thoughts. Not interested in auto switching, grid connect or any of that. wiring already in place to do this (simple system)

[jon_d]

Busman,

I have used MPP before. My controller had design issues in the way it controlled the charge voltage. I managed to keep it under control with AGM's but not with lithiums.

Had to throw it out and go Victron. I wouldn't use the brand again. Very little supporting information. Spare parts are available though.

[Busman]

Thanks Jon, exactly what I wanted to hear

[T1 Terry]

There is great support for the 48v versions on the AEVA forum with two Qld professors taking on the challenge after having issues with units they had fitted. The 24v stuff, very little support, replacement failed mother boards supplied under warranty aren't free as such, the last ones were around the $150 mark and that was when the AUD was worth something.

As Jon has already said, go Victron, the Multiplus 2 version is actually cheaper than the original and a better unit. No special cards to convert them from stand alone, parallel running and 3 phase configuration. Units on each phase can be also paralleled to increase the capacity on that phase and each phase can be run as a single phase at the same time as operating in 3 phase.

Be aware though, current limiting is a very important part of the install. In paralleled units you need to run long cables, the same length, rated to the normal max output and on the undersized end of the range, then joined at the supply junction box before going to an RCD. If you install the RCD before the junction box and one trips, the other inverters will attempt to carry the load .... that generally doesn't work out well at all.
The inverters are smart enough to sense if there is an earth neutral link on the supply side and switch the earth/neutral link on or off as required to avoid tripping an RCD on the supply side but providing one when on inverter supply so upstream RCD's work as designed.

T1 Terry

[T1 Terry]

Busman,

I have used MPP before. My controller had design issues in the way it controlled the charge voltage. I managed to keep it under control with AGM's but not with lithiums.

Had to throw it out and go Victron. I wouldn't use the brand again. Very little supporting information. Spare parts are available though.

As far as the support, the Taiwanese factory are happy to supply all the paperwork ... well PDF's but they can be printed out, to test and replace any item, you just have to pay freight from Taiwan.
What happened to the Rich units you were using, have you lost faith in them?

T1 Terry

[jon_d]

have you lost faith in them?

.

yep. I got boards at a reasonable price. The support was average. The problem wasn't solved.

I'd suggest that a forum devoted to supporting a commercial product goes to the nub (sp?) of the problem.

[Busman]

No still happy with Rich Electric but to import any more I have to buy 4. I can't see me using them so might as well go for something in the marketplace, The idea is to put up a small solar sysytem, say 6 Kw to supplement the house, and use the big lith battery in VP to run the house at night. Not grid connected, we already have the wiring installed in the switchboard with a switch (forgotten name of it) where you select grid or alternate power.So, with grid selectable back up we don't need a big solar system for our modest needs.
The only big user of electricity is the water heater, that is easily taken care of by a couple of solar panels and a DC element as I have done on VP just need to find the time to do it.

[T1 Terry]

No still happy with Rich Electric but to import any more I have to buy 4. I can't see me using them so might as well go for something in the marketplace, The idea is to put up a small solar sysytem, say 6 Kw to supplement the house, and use the big lith battery in VP to run the house at night. Not grid connected, we already have the wiring installed in the switchboard with a switch (forgotten name of it) where you select grid or alternate power.So, with grid selectable back up we don't need a big solar system for our modest needs.
The only big user of electricity is the water heater, that is easily taken care of by a couple of solar panels and a DC element as I have done on VP just need to find the time to do it.

I'm looking at putting 6 used house panels up in series and running the wires to the water heater element and use the thermostat to turn a DC solid state relay on/off. It might only be 6 amps @ 240v, but it's got all day to heat the water, maybe piggy back an Anderson plug to go to the Prius LTO battery when I finish that project, then the battery can heat the water and take what ever solar isn't needed by the water heater. No more off peak B/S where they don't turn it on because of a power shortage, or running out of hot water when we have visitors staying ... We have the solar hot water evacuated tube water heater along with another flat type solar water heater panel that was at the house in Lake Illawarra, but I just couldn't be bothered with the plumbing etc, mounting and wiring solar panels is so easy and just running the cable down to the hot water system already there makes for a much easier install.

T1 Terry

[Busman]

So you are going to put dc into the ac element, didn't know you could do this ?

In VP I run dc from 2000 watts of panels (24v) to a pair of dc 24 and 12 elements (3 times) and have a circulation pump to run the water out of the heater, through a container with the elements in and back into the 50 ltr domestic storage heater. This way I still have the 240 v ac element intact, still connected to the time switch it is on now, as backup as you say, for a house full of people or lots of cloudy days.

[jon_d]

Yes. You can.

240v ac rns has the same heating effect as 240v dc.

Just becareful of the switches being used. Dc doesn't cross through zero volts and therefore doesn't extinguish any arcing.