Xw 150/60

I installed an XW150/60 charge controller on a new system a few days ago and it's not charging like it should.
System specs: 10- Sonali SS-300 Vmp 37.58, Imp 7.58, Voc 44.64, Isc 8.45. 5 strings of 2 panels.
When is first connected the CC, batteries (8 Rolls S530) were topped off with generator and I wasn't too concerned that charge current was low at 150 watts at around 57 volts.
I wasn't able to get back for a few days due to weather but when I got there yesterday, it was doing about the same even though there was decent sun on the panels and the
batteries were needing charging. Incoming voltage was 74 with 54 out to batteries and showing (again) about 150 watts.
I went to combiner and found no problems there. Disconnected and measured short circuit current with my Fluke MM and it showed almost 8 amps from each pair with polarity right for all.
Checked all connections there and at the two breakers in the dist. panel. No measurable voltage drop (about 25' #6 thhn) anywhere in the system.
Log shows very low harvest and no faults or warnings. Settings are at defaults but I tried raising voltages and it made no difference.
Any ideas on what else I can check? I have 4 other systems running this CC and haven't had any problem with them.

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Xw 150/60

    What output current are you seeing to the batteries? That 2800 Watt array should be capable of around 45 Amps @ 48 Volts. This should be sufficient for the 400 Amp hour 48 Volt battery bank.

    Your input Voltage to the controller is only reaching 57 Volts? With two of those panels in series it should be over 70 Volts. Insufficient insolation?

    Output Voltage to the batteries should be near 60 Volts for the Surrettes during Absorb.

    If output current from the controller is low during what should be full sun, bypass the controller (don't worry about the Voltage as this is temporary) and check the current tot he batteries with a clamp-on DC Ammeter. If the current goes way up, the controller is not operating properly. Why becomes another investigation.
  • arkieoscararkieoscar Solar Expert Posts: 101 ✭✭✭✭
    Re: Xw 150/60

    " charge current was low at 150 watts at around 57 volts"
    57 volts was output of CC. Input has never been below mid 70's. Most I have seen for amperage to battery was around 4 amps. Array is 10 300 watt panels.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Xw 150/60
    arkieoscar wrote: »
    " charge current was low at 150 watts at around 57 volts"
    This should be expressed as Amps @ Volts for clarity.
    57 volts was output of CC. Input has never been below mid 70's. Most I have seen for amperage to battery was around 4 amps. Array is 10 300 watt panels.

    Output Voltage should rise with charging, but if only 4 Amps is coming out of that controller there won't be any charging. One reason why this would be is that the batteries are already charged. Resting Voltage for a 48 Volt system would be around 51-52. So you need to see if the charge controller is going through its stages and what is happening in those stages. 4 Amps output in Bulk is unlikely, but if the batteries go up to Absorb set at 57 Volts there may only be a need for 4 Amps to keep them there. Another test is to turn on load and see if the controller output current goes up.

    What you're looking for here is the reason for the low power. If it is not needed, the array will not generate full power. If it is needed and the array does not produce it but the array is capable of it (sufficient insolation and no malfunction) then the controller is not allowing the power to pass. This may be due to incorrect settings or defective controller.

    As I said, if you bypass the controller and the current goes up then the controller is blocking current for some reason. It may be as simple as having its output programmed too low (although 4 Amps would be ridiculously low). Or there may be something wrong with it. Comparing input power to output power may show that up.
  • VicVic Solar Expert Posts: 2,999 ✭✭✭✭
    Re: Xw 150/60

    ark ..,

    When you say that settings are at Default, for get what those are for the SCC. Some CC's defaults are for Gels, to be safe. These would be too low for these FLAs. You mentioned that you have tried changing the charge settings, but it made NO difference. So, does that mean that the CC accepted the changes, but there was NO change in the CC output current, and that the voltage did NOT change??

    You also mentioned that the batteries "needed charging" -- how do you know that the batts needed charging? Did you use a Hydrometer?

    As an aside, if the batteries are new, did you do a Comissioning Charge AND EQ, as specified by Surrette?

    As Coot mentioned, applying a largish load to the inverter output should cause the CC to supply more current -- does this happen?

    When this low ouput power (current) is seen from the CC "in good sun", what charge stage is the CC showing?

    Thanks, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • arkieoscararkieoscar Solar Expert Posts: 101 ✭✭✭✭
    Re: Xw 150/60

    default is FLA, 440 AH. I had set bulk, absorb and EQ up to Rolls' numbers when I installed the CC.
    I didn't check SG at that time because the battery had been commission charged and checked just a couple of days prior and wasn't used during that time.
    When I came back, I checked SG and it was 1.250 to 1.255.
    Nothing causes the CC to output more than what I stated in the first post. About 3.5 amps, regardless of charging voltage.
    Was hoping someone would know something else to check.
    I guess it's time to call tech. support tomorrow as the CC is the only thing left.
  • VicVic Solar Expert Posts: 2,999 ✭✭✭✭
    Re: Xw 150/60

    ark..,

    Well, if no added loads on the inverters cause the CC to deliver more current, in good sun on the PVs, then something is seriously wrong.

    Know that you mentioned checking the Isc of each string, and it is within expected values, then the PV seem fine. And if the sun is BRIGHT, and fairly directly on the PVs, then the CC must have a problem.

    Coot's recommendation of bypassing the CC and hooking the PV Combiner output directly to the batteries, seems like a good test. You should have a way to measure the current output from the PVs (clamp DC Ammeter ??), and you would want to monitor the battery voltage, as well.

    Am personally very un-impressed with the Schneider SCC. They are made in China, and in my experience the Firmware can be very Buggy, and updating FW requires a external box that has a price of about $350.

    The SGs that you note-- 1.250 -1.255 -- represent a battery bank that is about 95% charged. As you know, fully-charged Surrette Solar batteries read 1.265 SG. As you also know, there is a temperature compensation needed for Hydrometer SG readings, but, generally this is a fairly small factor, unless batts are very warm or cold.

    FWIW, Good Luck, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,221 ✭✭✭✭✭
    Re: Xw 150/60
    arkieoscar wrote: »
    default is FLA, 440 AH. I had set bulk, absorb and EQ up to Rolls' numbers when I installed the CC.
    I didn't check SG at that time because the battery had been commission charged and checked just a couple of days prior and wasn't used during that time.
    When I came back, I checked SG and it was 1.250 to 1.255.
    Nothing causes the CC to output more than what I stated in the first post. About 3.5 amps, regardless of charging voltage.
    Was hoping someone would know something else to check.
    I guess it's time to call tech. support tomorrow as the CC is the only thing left.

    Check your GFI installation. If you are negative bonded anywhere, one of the failure modes is the CC will limit output.
    Check the array by disconnecting it and shorting it into a good ammeter.
    There have not been firmware updates on this controller for 5 years. Over 10,000 sold and very reliable.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • BB.BB. Super Moderators, Administrators Posts: 30,629 admin
    Re: Xw 150/60

    To add to Dave's caution about grounding the solar array PV negative output...

    As I understand, the Schneider/Xantrex unit uses the negative lead from the array to monitor current from the array (as part of the MPPT calculations of Pmp=Imp*Vmp stuff).

    If you have any connection from PV negative (or positive) leads other than the Vin of the MPPT controller, the MPPT functions will not work correctly.

    There are other major MPPT mfg that do not measure negative lead current flow and you can bus the array negative leads directly to battery negative terminal/bus without any issues.

    It is not a design error in the Xantrex controller, it was just a choice the engineer made where to measure current--And otherwise works fine as designed.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • arkieoscararkieoscar Solar Expert Posts: 101 ✭✭✭✭
    Re: Xw 150/60

    array neg. goes directly to CC. Unit is being replaced under warranty. I have several of these going back years with no problems so I was surprised by it being defective.
  • arkieoscararkieoscar Solar Expert Posts: 101 ✭✭✭✭
    Re: Xw 150/60

    installed replacement cc late last week. It started charging more than original even though it was raining and completely overcast. Logs from over the weekend show it completed two charging cycles. Now to see if my customer has to eat all of the labor for changing the defective unit.
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,221 ✭✭✭✭✭
    Re: Xw 150/60
    arkieoscar wrote: »
    installed replacement cc late last week. It started charging more than original even though it was raining and completely overcast. Logs from over the weekend show it completed two charging cycles. Now to see if my customer has to eat all of the labor for changing the defective unit.

    Schneider might help if they prove the unit was not damaged in installation. It will take time and you have to have spent some serious money. If you marked the price up then in my opinion you eat the labor. At least some of it. I always like to give my customer the choice of buying the equipment directly from my dealer or my purchase through my dealer. If they buy it and get the price, then they have to pay for additional labor for this kind of thing. Lucky that this issue is rare. Good Luck!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

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