Inverter advice

[moggy1968]

HI All, got my biggest install ever (8kW) and my first G59 I am pricing up but I've hit a bit of a problem.
The system will have 2 different orientations so I need at least 2 Mppt trackers and all the inverters in the 7-8000w capacity only have 1 tracker (much to my suprise)
I then looked at using two 3.6s, but still have the same roblem that I would have to then connect the AC in parallel which will drop the amps to the lowest of the 2 outputs
Its single phase
Any ideas/solutions most welcome.

 

[BruceB]

I then looked at using two 3.6s, but still have the same roblem that I would have to then connect the AC in parallel which will drop the amps to the lowest of the 2 outputs.

Come on Moggy, I know from your other posts you know better than that!

The amps and volts of the inverter outputs will sort themselves out. But put the inverters on separate mcbs.

 

[moggy1968]

that would mean 2 seperate meters though, is that likely to be a problem?
I might be trying to make this harder than it needs to be (fear of the unknow!!!!)!!!!

 

[BruceB]

There is no problem having 2 inverters on a single meter. A reason to have a separate meter would be if you were extending an installation later, but no advantage I can see otherwise.

 

[moggy1968]

Sorry if I'm being thick here (don't worry, you get used to it after a while) if I combine the two AC strands don't I have the same problem with the current, i.e. it will default to the lowest level, so, if one inverter is kicking out 5 amps, the other 1 amp won't the whole lot drop to 1amp? If I combine after the meter that matters less as each meter will read the outputs before they drop?:willy_nilly:

 

[BruceB]

No, the voltage will be at the same level, but the current of one will not affect the other (apart from as the voltage adjusts then the current will adjust to match. DC power in must equal AC power out (roughly).

 

[moggy1968]

DOH! of course, current is added together in parallel, voltage drops to the lowest denominator, but as both inverters are producing the same (ish) that doesn't matter.

cool, thanks for clarifying that I'm worrying about nothing Bruce!
I shall now go for a lie down in a dark room with a wet letuce on my forehead, once I've checked I really did switch the gas off and put the cat out!!!

 

[Del Boy]

Moggy,

Sorry if this is too late, but have done something similar with 2x SMA 4000TLs on a single phase. Have ended up with 4 MPPT if that makes sense? 2 per inverter.

One has a bit of shade later on in the day and as a result the inverter generates less than the other. Can easily be seen either on the display, via the SunnyBeam or Sunny Explorer.

On a side-note, I couldn't find any G59 cert 8kW inverters, and didn't want to fit a G59 relay.

Cheers,

Del Boy