Hello all!!!

[Richard_Li]

Hello everyone! Thought I would start with an introduction before going nuts and asking questions

I have semi recently got a Schneider Solar system installed

XW-6848+ Inverter
2 x MPPT60 Charge Controllers
16 x 6v AGM battery bank at 48v
and 30 Solar panels at 320w each. Running in sets of 3.
Conext Combox (for browser access)

Hoping to wander around here and see what people have to say about the schneider system and hopefully get accustomed to the inner details and cofigurations.

 

[Hedges]

I haven't used Schneider, but people here who do say it is solid.

Is this an on-grid system, or off?

I have 8x 6V L16 size AGM, maybe half your size.
What model AGM? Mine are SunXtender, I expect up to 650 cycles to 70% DoD, sufficient for grid backup during their 10 year float life.
If you are off-grid and cycle nightly, suggest limiting power draw for 15% DoD so they last a long time.

PV panels and inverter cost about $0.025/kWh (amortized over 20 years) and AGM costs $0.50/kWh (over cycle life).
So goal should be to use power as it is produced by PV, curtail production when excessive, avoid cycling batteries.

Your 10kW of PV and guessing 40 kWh of AGM could charge at 0.25C, which may be within acceptable range.
If you add more PV, have a way to regulate charge current to optimum value.
I have more PV, less battery. I regulate it to 0.2C (AC coupled SMA system.)

 

[MisterSandals]

30 Solar panels at 320w each. Running in sets of 3.

This sounds odd. A set is 3 in series or 3 in parallel?

Either way, it sounds really odd:
3S10P would be about 100A
3P10S would be a lot of ~30A connections on MC4 connectors

3 strings of 10 panels in series? (10S3P)

 

[Richard_Li]

that was a fair amount of information.... in a language I don't quite speak fluently yet LOL

the batteries I believe were Deka or Deak, I'd have to go back out and look at the spelling again but definitely started with a "D" and are 225ah each. running two strings of 8 in parallel I get a solid 250ah. Everything in my house minus some big appliances like Heat/AC , Washer/Drier, Stove/oven run on solar and the battery backup. I specifically wired the hot water heater and water pump since those are things I deemed as hard requirements. I think the batteries only get used when grid dies out, and I am A/C Coupling so even during long dreary weeks something will keep them topped off.

The system is Grid-Tie and I feed a fair amount back into the grid. 10kw (which I'll never see) is stifled since the 6848 has a max invert capability of roughly 6ish LW. I obviously am overcompensating like a proper dude! I've gone through the night without grid power a few times and the system did what it was supposed to, come daybreak everything recharged and went back to normal... at least I think so

The Combox is a newer addition, which is why I came about to find this group! so many things going on in the inverter and so many options I didn't know went into the operation of this! I love knowing how things tick and I suspect the default settings when it was setup is far from optimal, so I'll be asking questions here about some of the not-so-obvious settings.

 

[Richard_Li]

This sounds odd. A set is 3 in series or 3 in parallel?

Either way, it sounds really odd:
3S10P would be about 100A
3P10S would be a lot of ~30A connections on MC4 connectors

3 strings of 10 panels in series? (10S3P)

3 panels in series x 10 strings

it was originally setup with 24 panels and 8 breakers

I added 2 more breakers and 6 panels, all Q-Cell panels

Is this not an optimal setup? If not what would be better and I can always rewire things

And I believe you are correct, on the two solar charge controllers on the bright days I see it read at 100-ish amps

 

[MisterSandals]

2 x MPPT60 Charge Controllers

How are your 10 strings connected for these 2x MPPT60's? 5 strings in parallel to each in a combiner box?

What are the max input volts and MPPT (optimal) voltage range of the MPPT60's?

This info needed to determine optimal array config to MPPT wiring.

 

[Richard_Li]

How are your 10 strings connected for these 2x MPPT60's? 5 strings in parallel to each in a combiner box?

What are the max input volts and MPPT (optimal) voltage range of the MPPT60's?

This info needed to determine optimal array config to MPPT wiring.

yep, 5 going to a combiner box, with the connections split evenly to each Charge Controller. I haven't looked up the optimal specs for these MPPTs, should probably poke at those huh.... BRB!

 

[Richard_Li]

yep, 5 going to a combiner box, with the connections split evenly to each Charge Controller. I haven't looked up the optimal specs for these MPPTs, should probably poke at those huh.... BRB!

quick interweb search produced the following specs...

• 3500 W maximum output power (48 V systems)
• 12, 24, 36, 48, 60 V nominal battery voltage
• 150 V max. PV array open circuit voltage
•Compatible with XW Pro and SW

I have seen these max out at 3500 a few times, since I'm over provisioned at 48v battery bank
Can't say I've paid much attention to the voltage but it says 150 max so I would imagine around 100 would be nominal.

The reason I got the combox is because I would rather be at my PC watching readings than sitting in my garage

 

[MisterSandals]

I have seen these max out at 3500 a few times,

Thats ok, it just gets clipped. Being over paneled will start charging earlier and produce more in other low light conditions.

Can't say I've paid much attention to the voltage but it says 150 max so I would imagine around 100 would be nominal.

Seems mighty reasonable voltage-wise but you have not told us exact panel volts (Vmp). The wiring, connectors and fusing needs to handle 5x the panel Imp (amps).

Nice system!

 

[Hedges]

Inverter limited to 6kW, you say SCC 3.5kW each for 7kW.
Are all PV panels oriented same, so would clip if 10kW available? flat top at 7kW.
If two orientations into each SCC, 10kW of panels could peak at 7kW but for longer per day.

If your water heater is on battery backup, consider a relay to disconnect it during times when grid down and battery not full. Let water heater serve as a dump load for power once battery full.

Battery wants to charge at some ideal rate (think it is 0.2C for mine), then be held at absorption for a couple hours. Cycling water heater on and off isn't ideal for that, but maybe water heater plus absorption is within PV production. A 240V heating element (typically 3500W) can be run on 120V for 1/4 power, 800W. Maybe top element and fed by grid, bottom by 120V from inverter? Need thermostat and over-temperature switch protecting both.

 

[Richard_Li]

I kinda always wondered what all this meant LOL I figured it it was all the panels were the same it would be fine. I am pretty sure I'm cooking my batteries during the charge cycle, defaults seemed high to me but nothing caught fire yet.... ignorance is bliss I suppose