Needing assistance

myronmyron Registered Users Posts: 11 ✭✭
Let me get it straight, I have been reading on solar for many years and want to say it is more complicated in practice than in theory. So this is my issue, I got an installer and this what I initially had:
2 255w 24v panels, 1500 inverter, schneider c40 pwn charge controller, the breaker box (midnight). Not sure the wiring type from the panels down but I suppose those are adequate. Battery to charger is 2/0 and 4awg from charger to inverter. 
I recently did myself, a third panel, so that is not roughly 750 watts, changed the inverter to a schneider 4048 only thing changed was i got some 6 awg from the charger to the inverter as I read that was the wire. Might go back to the 4awg if necessary. Also i added 4 more batteries (8 trace 225amps 6v). I want am a bit nervous after reading up on wirings and associated issues. Is that wiring good enough? I tried running a microwave and the microwave sounded like it was experiencing low voltage ( i suspect this might be 2.5mm wire i joined to 6mm going from the inverter to the house. Your assistant is needed, I really want this be safe. I know I should get a mppt controller but no cash yet. Please advise me where I went wrong, if any and what adjustment to make. The panels are series together (all 3).

Comments

  • littleharbor2littleharbor2 Solar Expert Posts: 704 ✭✭✭✭
    255 watt panels sound like 60 cell panels. This isn't a 24 volt panel and won't work properly with a c-40. So before I make an ass on myself lets determine if these are 60 cell panels.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • myronmyron Registered Users Posts: 11 ✭✭
    How do I check they 60 cells? They mark 24 volts though
  • myronmyron Registered Users Posts: 11 ✭✭
    I know the c40 isn't ideal but that is all I got at the moment
  • littleharbor2littleharbor2 Solar Expert Posts: 704 ✭✭✭✭
    edited November 23 #5
    myron said:
    How do I check they 60 cells? They mark 24 volts though

    Count them. They would be 6 across and 10 high. People who don't know much about solar sell solar equipment all the time. A 24 volt panel would be 72 cells with a Vmp. of around 36 volts and an Voc. of around 45 volts. 60 cell panels are lower voltage, insufficient for fully charging a 24 volt battery

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • mcgivormcgivor Registered Users Posts: 1,304 ✭✭✭✭
    Are you converting from 24V to 48V nominal.? The addition of batteries would indicate this, if so it's not good practice to add new batteries with old, especially in series, unless very close in age < 6 months and in excellent condition. To use 3 panels in series with the PWM charge controller for 48V nominal  would be too high a voltage and may cause damage to the CC. Even 4 panels in series parallel, if they're 60 cell panels, is not recommended as the voltage would be too low, so it would appear that a MPPT controller is the only solution.
    The statement "Battery to charger is 2/0 and 4awg from charger to inverter." is confusing, the inverter should be connected to the battery with large conductors with appropriate overcurrent protection. typo?
    Adding  smaller gauge conductors in series with larger is bad practice, the overcurrent protection would have to be sized for the smallest conductors or they would be in effect be a fuse, in the event of a short circuit.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • littleharbor2littleharbor2 Solar Expert Posts: 704 ✭✭✭✭
    myron said:
    I know the c40 isn't ideal but that is all I got at the moment

    You need 24 volt panels (or series wired 12 volt panels) with that PWM controller.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • myronmyron Registered Users Posts: 11 ✭✭
    so it is best i go back to the 24v inverter until i can purchase a mppt? I was just trying a thing as I had purchase those and they were just lyng around.
  • myronmyron Registered Users Posts: 11 ✭✭
    These are 24v panels. I think should start over. 3 24v panels rated at 255 and 250 watts, a 4048 inverter and c40 charge controller (pwm) to a 48v battery bank. You are saying the 3 panels series together will damage the charge controller? 
  • myronmyron Registered Users Posts: 11 ✭✭
    Is the charge controller rated for 60 amps? :/. I think i am lost
  • littleharbor2littleharbor2 Solar Expert Posts: 704 ✭✭✭✭
    What is the Vmp and Voc of these panels? You still haven't established whether these are 60, or 72 cell. If you cant tell us that the voltage will tell us. The controller is a 40 amp controller but it is the only one of the c series controllers that does 48 volt charging.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • myronmyron Registered Users Posts: 11 ✭✭
    Sorry man, when I get home it is already dark to go on the roof. I am in Jamaica. Saturday I will be able to count the cells. For now I am told I need to connect the panels individually to a combiner box and then send it to the charger, correct? They are 24v panels, so the 3 series together is 72v, too much for the charger?
  • WaterWheelWaterWheel Registered Users Posts: 242 ✭✭✭
    A separate point,... and keep in mind that others on this site are much more knowledgeable than I am...
    Considering the 4048 inverter and 4 additional batteries now I'm assuming 24v before and 48v now.     But for this point it really doesn't matter.      With the additional batteries you need a higher charging rate to properly charge that battery bank assuming daily use, somewhere around 1800 watts in panels to provide a C/10 charging rate to 8 of those batteries.

    But first as others have said you need to make sure that the panels are providing enough voltage by wiring them in series.     But with only 3 panels you may not be getting high enough voltage for enough hours a day for a proper charge cycle.

    Using a DC capable voltage meter touch the wires from the panels and tell us what the voltage is.

    2 years of experience (very little compared to most on this site) has taught me that a properly operating solar system is all about balance.    Battery bank to loads, panels (charging amps) to battery bank, ect.

    Conext XW6848 with PDP, SCP, 80/600 controller, and conext battery monitor

    18 SW280 panels on Schletter ground mount

    48v 790 amp/hr Crown battery bank

  • myronmyron Registered Users Posts: 11 ✭✭
    I really want to apologize for any arrogancy, I am not an electrician so most of the jargons I am lost on. Saturday I will get a voltage meter or at least count the cells. I just don't want anything to happen to the system. Yes the system is a 48v system now. The other info was just telling you what it was coming from. I really appreciate the patience.
  • EstragonEstragon Registered Users Posts: 1,616 ✭✭✭✭
    A couple of thoughts:

    You mentioned the wire size from "charger to inverter". The charge controller output should go to the battery (or battery buss).

    Have you checked/set the ac frequency on the new inverter? It may be set to 60hz by default, but I think you may need 110v -50hz.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • myronmyron Registered Users Posts: 11 ✭✭
    > @Estragon said:
    > A couple of thoughts:
    >
    > You mentioned the wire size from "charger to inverter". The charge controller output should go to the battery (or battery buss).
    >
    > Have you checked/set the ac frequency on the new inverter? It may be set to 60hz by default, but I think you may need 110v -50hz.

    I will look into that, like I said I really new at this. I used to read up, but the information made it look so easy. There was never anything on wiring sizes, breaker etc. Just say to connect the solar to charger and then charger to battery, battery to inverter.
    I am grateful for all the help so far. Tomorrow I will get a combiner box to put the panels since you all suggested that 3 panels series together is too high a voltage for the pwm charge controller. So will connect the panels individually to the combiner box on the roof then back to the wires going down to the charge controller. But how? I was told I need a breaker also
  • EstragonEstragon Registered Users Posts: 1,616 ✭✭✭✭
    We can't say yet whether 3 in series is too much, as we don't have the Voc and temperature coefficients for the panels. I think the controller can take up to 125v. In order to see if a series string of three could overvoltage the controller, you have to calculate the combined Voc, adjusted for the coldest low temperature ever for your location.

    Wiring 3 in parallel won-t charge a 48v bank.

    For one or two strings, you don't really need breakers, but they're handy as disconnects. The size should be spec'd by panel maker, often 15a. A breaker IS required between the controller and battery, and between inverter and battery. Size of wire and breaker is generally spec'd by manufacturers.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • myronmyron Registered Users Posts: 11 ✭✭
    > @Estragon said:
    > We can't say yet whether 3 in series is too much, as we don't have the Voc and temperature coefficients for the panels. I think the controller can take up to 125v. In order to see if a series string of three could overvoltage the controller, you have to calculate the combined Voc, adjusted for the coldest low temperature ever for your location.
    >
    > Wiring 3 in parallel won-t charge a 48v bank.
    >
    > For one or two strings, you don't really need breakers, but they're handy as disconnects. The size should be spec'd by panel maker, often 15a. A breaker IS required between the controller and battery, and between inverter and battery. Size of wire and breaker is generally spec'd by manufacturers.
    >
    Thank you my friend. I will try to get a pic of the back of the panels tomorrow and get that info. Was trying to read the info from online sheet but it has be clueless
  • myronmyron Registered Users Posts: 11 ✭✭
    Sorry for the lengthy delay, life. Anyway I if I remember correctly it is 60 cell. I think the string is ok for now though.
  • westbranchwestbranch Solar Expert Posts: 4,873 ✭✭✭✭
    Myron, on the bottom edge there are 2 grey cables...  I assume they are going to the Charge Controller, right?
    Q #2 are there any other cables going to the CC? NO?  It looks like ,in the shade, there is a splice covered with electricians tape or bicycle inner tube and a wire wrap, if so there should be 2 splices, one in each cable heading to the CC,
     If that is what you have you have 2 PARALLEL PV panels =  1 X stated voltage and the spliced wires , at the CC will have 2 x the Amps (of 1 PV). this setup and a PWM CC will not quite fully charge your 24V batteries
    If this is not the way the wiring is and there are no splices and the negative lead from one PV goes to the Positive lead from the other panel you have a SERIES STRING of 2 PV panels = 2 X the PV voltage and 1 X the Amps at the CC. This setup needs a MPPT CC to be able to fully utilize your 24V batteries  and will need 3 panels to feed a 48 volt battery properly.
    Hope this helps

     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge, Hughes1100 Sat Modem
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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