Schneider Power Flow

josuegd · September 2020

Hi everyone, I'm new in this area,

I have XW6848/(2) MPPT60/(8) 280 batt/(12) 330W panels, 48V

No matter what I change on XW6848, It's seems that nothing happens. I do not want to sell (anyways I do not have net metering)

I have Enhance grid support (64V), Grid support Sell, but 0 amps.

Let say I have 1kW coming from panels, battery voltage at 54.7 and load about .5kW. From time to time charge is used from batteries having power from panels to recharge the batteries, but nothing to load. While batteries are getting fuel panels power start to drop until batteries gets fuel. Then panels power start to increase and supply to battery and load.

I tough that power from panels will maintain the incoming having batteries changed and supplying power to loads. At least that's what I want, keeping batteries changed and supply the rest to the loads.

josuegd · September 2020

Can someone provide some ideas on what going on?

super11b · September 2020

I am not an expert...I just installed my system. Here is where I started when I had issues.

Are you getting F66 or F69 error codes? (if so that was solved with an AC sense connection)

I started with going over all of the wiring:
1. Panels. Makes sure your strings are all correct. I had 3 panels per string.
2. Combiner Box. Check all your wiring. I checked my voltages at the combiner box with a meter to make sure I was seeing the right voltage.
3. Not sure if this was a DIY system or not. Mine was. I went through the wiring diagram and checked all of the wiring in the inverters to make sure it was in the right place per the Schneider wiring diagram. If I had the diagrams in front of me I could tell you exactly where they need to be.
1. The two inverters have inter connections between them.
2. PV negatives have a specific place.
3. PV positives have a specific place.
4. Battery Cables have a specific place.
5. AC out has a specific place to your panel.
6. AC sense connection. (hence the F66 or F69 error message)
7. Do you have a Scheneider SCP? or Commbox?
8. I have 2 x Midnight Solar Classic 150's so I can't speak to your controllers.

Has you systems been programmed? What is the programming that is on it now?

I have a Fluke meter with an amp clamp so I was able to measure all of my voltages and amperage use. AC and DC.

I had issues, but they were all because of my electrician. I ran out of time so I hired him to do the wiring. He got 75% of it right. I fixed the rest and got my AC output to my panel. He wired the AC1 Out wrong plus a couple of other minor things which I fixed. I started out with the wiring though to make sure all of the basic "stuff" was correct and confirmed it with my meter and the wring diagram. Once I fixed the wiring it was all good. Now...the configuration on the inverters and controllers had to be adjusted based on my batteries. Fortunately I found someone smarter than me to do that. Still had a bad battery though.

Batteries...make sure you are using a balanced battery system and the right wiring. I used 4/0 cable on all of the batteries.

Anyway I hope that helps a little.

MichaelK · September 2020

Let say I have 1kW coming from panels, battery voltage at 54.7 and load about .5kW. From time to time charge is used from batteries having power from panels to recharge the batteries, but nothing to load. While batteries are getting fuel panels power start to drop until batteries gets fuel. Then panels power start to increase and supply to battery and load.

I tough that power from panels will maintain the incoming having batteries changed and supplying power to loads. At least that's what I want, keeping batteries changed and supply the rest to the loads.

I'm have some difficulty understanding exactly what you are talking about, so lets break this whole statement into its component parts?

1) Let say I have 1kW coming from panels, battery voltage at 54.7 and load about .5kW. OK, what you are saying is that you are reading 1000W coming into the charge controller, and 500W of load is being consumed at the inverter. Is that correct? 500W should be going to the load, and the other 500W is going to the battery. You should see the voltage slowly creeping up higher than 54.7V as this happens.

2) From time to time charge is used from batteries having power from panels to recharge the batteries, but nothing to load. I don't understand what you are saying here? Are you saying that power from the solar panels is dropping and it's only charging the batteries but not running the load? How do you know this? What is the load? How do you know the load is not being powered?

3) While batteries are getting fuel panels power start to drop until batteries gets fuel. This sounds like battery charging is prioritized instead of powering your load? Just how are you measuring power drop?

4) Then panels power start to increase and supply to battery and load. It sounds like as the day progresses towards noon, the panels are producing more power till both the batteries are charged, and the load is being powered.

5) I tough that power from panels will maintain the incoming having batteries changed and supplying power to loads. I think what you mean here is that you are expecting the power from the panels to keep the batteries charged and power the loads? In the case of my XW+ the priority for my system is that the loads get supplied first, and excess power is used to charge the batteries. If the incoming power is not greater than the load, the load's power is supplied by whatever solar is available, and the rest comes out of the batteries. So, with a load bigger then the incoming solar, the batteries will drain.

6) At least that's what I want, keeping batteries changed and supply the rest to the loads. You want to prioritize charging over loads. I haven't tried programing the XW+ that way, and I don't know if you can. The only way I know of that the XW+ can shut off a load is by reaching the low battery voltage and initiating shutdown. I'm sure you don't want that to happen?

We have to know what kind of batteries you have to know exactly how you should be programing your XW+. In my case, I am using Trojan L-16REB batteries, with the batteries bulk charging at 59.6V and floating at 54.4V. To do any programing on the XW+ at all, you need either a ComBox, or an SCP. Do you have either? If not, you really can't change settings in any way.

mcgivor · September 2020

Your description is difficult to decipher but from what I understand you want to know why the inverter is using energy at times to charge the battery rather than strictly using solar to support the load.

Judging from the voltage the battery is in float, if this is the case its important to understand that even at float, the voltage is higher than its normal standing fully charged value of ~51V, the charger needs to maintain that slightly elevated float setpoint by passing current to them to prevent voltage from dropping. The amount of current required to maintain float is determined by the Ah capacity of the battery along with its age and or condition.

Because the solar input and inverter are connected at same place, essentially the battery terminals, the solar will naturally divert to the inverter/load provided it has sufficient capacity to support it, with a portion being used by the charger to maintain float. However if the solar output is marginal at any point, caused by a passing cloud for example, the inverter will take a bite out of the battery dropping it's voltage below float, the charger would then need to replace the energy withdrawn, so charging occurs.

These dynamic changes are occurring constantly which are not cause for concern, based on my understanding of the question.

Schneider Power Flow

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