New System, LOW OUTPUT. Neet help

bloodofheroesbloodofheroes Registered Users, Users Awaiting Email Confirmation Posts: 15 ✭✭
I have five 250w 36v panels, I am in Arizona, so sun is not really an issue. The problem is that I have low wattage. My angle is right, but I can only get about half of what these are rated.

Problem two, I can only hook up two of these at a time. It doesnt really matter which ones. I can hook up any two and get 260w, but when I hook up the other three, they only put out about 25w each of additional power. It doesnt matter which combination I use. Any ideas?

Comments

  • littleharbor2littleharbor2 Solar Expert Posts: 635 ✭✭✭✭
    I see you have posted in the grid tie category. Please describe your components, wiring scheme and whether you have an agreement with the power company.

    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.

  • bloodofheroesbloodofheroes Registered Users, Users Awaiting Email Confirmation Posts: 15 ✭✭
    edited September 17 #3
    I am wired from the panels to the grid tie inverter. It is 1000 watt capacity. It is wired parallel. I do not have any agreement with the power company.
  • BB.BB. Super Moderators Posts: 26,758 admin
    Can you link to the gt inverter you are using?

    Also, exactly which solar panels you are using?

    And how you know the watts you are generating? (Meter on gt inverter, utility meter?)

    Details matter here.

    - Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • OceanOcean Registered Users Posts: 39 ✭✭
    Assuming you have one controller, You can have two parallel strings of two panels, or two strings of three panels, but not one string of two and another string of three.  You will essentially never see power from the 5th panel.  Also, is it possible your batteries are already charged up?  Maybe it only takes 260 watts to keep them floating...  What kind of charge controller do you have?  How are you connecting your panels?  Must be very clear about it...
  • Raj174Raj174 Solar Expert Posts: 405 ✭✭✭✭
    @Ocean
    It's a grid tie inverter, so no controller and no batteries.

    Rick
    12 x 300W Renogy PV, MNE175DR-TR epanel modified, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 195AH HI Power LiFePO4 no BMS, 4000W gen.
  • OceanOcean Registered Users Posts: 39 ✭✭
    I see... my mistake.  and I really don't know Grid Tie very well.  But it's a curious question then...  still.  How is he "hooking up the other three"?  In series with the first two?  In parallel along side the first two (would only really double the amps - but will the inverter take that many amps?)... maybe the controller is limited on amps? Or volts?  What's the O.C. max voltage of the inverter?  so many questions!
  • OceanOcean Registered Users Posts: 39 ✭✭
    @bloodofheroes
    you say "it is wired in parallel"... exactly what is wired in parallel?  Are all five solar panels wired in parallel?  What do you mean?
  • PhotowhitPhotowhit Solar Expert Posts: 4,195 ✭✭✭✭
    With these "burn your house down"/"Power company please disconnect me" grid tie inverters. I don't know what the most energy they can use is.

    Please understand that the panel rating of the panels is somewhat over rated for Normal Operating Cell Temperature of the panel. Many panels publish a NOCT value, it is generally 75% of the name panel or a 100 watt panel could be expected to produce 75 watts while angled close to directly perpendicular to the sun. This could explain much of your loss.

    The charge controller can only process one voltage level at a time, so if you have 60 cell panels that produce 31 volts and have a string of 2 so that the voltage adds to 62 volts, adding a single panel of 31 or 36 volts or a 72 cell panel or string of panels, can confuse the inverter making it search for a correct Maximum power point (MPPT Maximum Power Point Tracking)
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • bloodofheroesbloodofheroes Registered Users, Users Awaiting Email Confirmation Posts: 15 ✭✭
    edited September 18 #10
    This is how I have them wired.

    I do not have a charge controller or batteries. It goes directly to the grid tie, Which I have two of, and both work great with the other three panels that I have. (The other three are different than the five, so I keep them separate.)

    This is my grid tie inverter, yes, it is cheap, but as I said, it will work great with my other three panels, and even one of these if I want to hook it in.




    And these are the panels that I am having trouble with. Its almost like I am capped at 260 watts. Two will go to 240-260, and any additional panels that I hook up will only give me about an additional 25w. I have hooked them up several different ways and its consistently the same.

    All my panels are the same.

  • EstragonEstragon Registered Users Posts: 1,416 ✭✭✭✭
    So all the positive wires from the panels come together, and all the negative ones do as well?

    How are the positive wires joined (combiner box - if so, what kind)?

    How long are the common positive and negative wires between the combiner and the inverter, and what wire size?

    Do you have fuses or breakers anywhere? If so, where and what size?
    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
  • OceanOcean Registered Users Posts: 39 ✭✭
    Just wondering if it's those three panels.  Do all of the panels work?  Meaning, can you hook up any two of the five and get 260 watts?

    If you take one out in the direct sun, cover it, connect it's wires together, and then uncover it, and measure the amperage flowing through the wires (the Short Circuit Amperage).  You should see something close to it's Isc ratings (8.xx amps).  Disconnect the wires and verify the Open Circuit Voltage (37.x).  This would at least verify if the panels are good...

    If you look into the manual for that grid tie inverter, is there a maximum input Amperage (Current).  1000w / 45volts is just over 20 amps.  Two of your panels together in parallel make up to max 16 amps... but due to sunlight conditions your actual operating input voltage and amperage might be way down... like even down to 20 volts.  You hook up another panel and you have max 24 amps flowing into the unit but still .  Probably you don't get the full rated sunlight.... so If the unit was limited to perhaps 22 amps, it might not give you any more power unless you were to increase voltage up to the max of 45 volts...

    You said you have other panels on a different inverter.  Have you tried any of them on this inverter (removing all of these panels and using the others to test this inverter)???
  • bloodofheroesbloodofheroes Registered Users, Users Awaiting Email Confirmation Posts: 15 ✭✭
    I have mixed and matched. Outcome doesnt change.

    I am getting about 24v while it is on the inverter, and when it is disconnected I get about 36v.

    According to the manual, the inverter will take 45 amps. It is almost like it is limiting me to 10 amps though.

  • EstragonEstragon Registered Users Posts: 1,416 ✭✭✭✭
    > @bloodofheroes said:
    > I have mixed and matched. Outcome doesnt change.
    >
    > I am getting about 24v while it is on the inverter, and when it is disconnected I get about 36v.
    >
    > According to the manual, the inverter will take 45 amps. It is almost like it is limiting me to 10 amps though.

    It may or may not be the inverter limiting you to 10a. It would help if you could answer the question about the wiring.
    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
  • Raj174Raj174 Solar Expert Posts: 405 ✭✭✭✭
    @bloodofheroes
    The inverter states what looks like 20 -15 volts DC input, the panel voltage is too high. Looks like it requires 12 volt nominal panels, 17 to 21 volts.  Check the voltage on the 3 panels that do work.

    Rick
    12 x 300W Renogy PV, MNE175DR-TR epanel modified, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 195AH HI Power LiFePO4 no BMS, 4000W gen.
  • littleharbor2littleharbor2 Solar Expert Posts: 635 ✭✭✭✭
    Looks like 20 -45 volts.

    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.

  • littleharbor2littleharbor2 Solar Expert Posts: 635 ✭✭✭✭
    edited September 18 #17
    If you have the 22.5 volt panels parallel wired ,the 22.5 volts is open circuit voltage. The Vmp. of those 12 volt panels is  less than 20 volts. So which panels are giving you trouble The 12 volt panels or the 250 watt panels? I may be reading this wrong . Where are you getting the 22.5 volts number from? 22.5 volts sounds like a 12 volt panel.

    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.

  • bloodofheroesbloodofheroes Registered Users, Users Awaiting Email Confirmation Posts: 15 ✭✭
    Raj174 said:
    @bloodofheroes
    The inverter states what looks like 20 -15 volts DC input, the panel voltage is too high. Looks like it requires 12 volt nominal panels, 17 to 21 volts.  Check the voltage on the 3 panels that do work.

    Rick
    Its 20-45VDC

    I have about a forty foot run of 14/2. No fuses or breakers (yet). They are just wired together with wire nuts.
  • Raj174Raj174 Solar Expert Posts: 405 ✭✭✭✭
    Opps, my bad.
    12 x 300W Renogy PV, MNE175DR-TR epanel modified, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 195AH HI Power LiFePO4 no BMS, 4000W gen.
  • bloodofheroesbloodofheroes Registered Users, Users Awaiting Email Confirmation Posts: 15 ✭✭
    edited September 18 #20
    If you have the 22.5 volt panels parallel wired ,the 22.5 volts is open circuit voltage. The Vmp. of those 12 volt panels is  less than 20 volts. So which panels are giving you trouble The 12 volt panels or the 250 watt panels? I may be reading this wrong . Where are you getting the 22.5 volts number from? 22.5 volts sounds like a 12 volt panel.
    MY BAD!!! SORRY!! The wiring diagram reflects nothing in the way of the ratings of my panels. I was just trying to show how I have them wired with that picture. It doesnt reflect the panels that I am using. Sorry for the misunderstanding.

    My panels are all 37.5 VOC. and 30.1 Vmp.
  • littleharbor2littleharbor2 Solar Expert Posts: 635 ✭✭✭✭
    !4 ga. wire is awfully light gauge  for 80 running feet of low voltage dc power.

    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.

  • bloodofheroesbloodofheroes Registered Users, Users Awaiting Email Confirmation Posts: 15 ✭✭
    edited September 18 #22
    !4 ga. wire is awfully light gauge  for 80 running feet of low voltage dc power.
    What do you recommend? Do you seriously think that this is the problem? Its 40 foot.
  • littleharbor2littleharbor2 Solar Expert Posts: 635 ✭✭✭✭
    40 run is 80 feet round trip which is what you need to figure with DC. Look up a voltage drop calculator online and plug in your numbers as accurately as you can. You could be losing a good portion of your power. 14 ga. wire may be acceptable for higher voltage in your case being that you would be pushing much less amperage at high voltage. I wouldn't use anything smaller than 8 ga. for that low voltage run. Still you won't find much love for that type of grid tie inverter here. They are potentially dangerous. If, in the event of a fire, it's discovered you are using this kind of inverter you will likely be found liable for property damage and possible death. Not a good scenario.

    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.

  • EstragonEstragon Registered Users Posts: 1,416 ✭✭✭✭
    > @bloodofheroes said:
    > littleharbor2 said:
    >
    >
    > !4 ga. wire is awfully light gauge  for 80 running feet of low voltage dc power.
    >
    >
    >
    >
    > What do you recommend? Do you seriously think that this is the problem? Its 40 foot.

    What's probably happening, IMHO, is as you put more current through the wire it heats up, increases resistance and voltage drops below the 20v min the inverter needs. The wire nut connections also may not stand up to high currents. As LH2 suggests, you should look up values in a table (NAWS has them online). Something like 4ga for 40' with 5% voltage drop.

    The five panels have potential current of ~40adc. 14ga is good for 15aac - using it for 40adc is dangerous. Also, you didn't say anything about fuses or breakers. Each parallel positive wire should be protected, as should the common run to the controller.
    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
  • WaterWheelWaterWheel Registered Users Posts: 218 ✭✭✭
    edited September 18 #25
    You need to use 8ga wire.     The fact that you are trying to run over 30 amps through 14 ga wire and that you are using an illegal inverter makes me suspect you need to unhook those inverters until you've double checked everything and read up on the islanding requirements and certifications.       As of a few years ago there were no "plug into the wall receptacle"  UL certified inverters available in the US.      If you do have a fire I doubt your homeowners insurance will pay.      If you kill a line repair man because you're illegally back feeding the grid with a non UL approved inverter life will not be good.

    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

  • bloodofheroesbloodofheroes Registered Users, Users Awaiting Email Confirmation Posts: 15 ✭✭
    Estragon said:
    > @bloodofheroes said:
    > littleharbor2 said:
    >
    >
    > !4 ga. wire is awfully light gauge  for 80 running feet of low voltage dc power.
    >
    >
    >
    >
    > What do you recommend? Do you seriously think that this is the problem? Its 40 foot.

    What's probably happening, IMHO, is as you put more current through the wire it heats up, increases resistance and voltage drops below the 20v min the inverter needs. The wire nut connections also may not stand up to high currents. As LH2 suggests, you should look up values in a table (NAWS has them online). Something like 4ga for 40' with 5% voltage drop.

    The five panels have potential current of ~40adc. 14ga is good for 15aac - using it for 40adc is dangerous. Also, you didn't say anything about fuses or breakers. Each parallel positive wire should be protected, as should the common run to the controller.
    I appreciate all the help. I thought that I was pretty smart, but found out really fast not as smart as I thought I was. I am going to add fuses, ect. but right now I am just trying to get this running. What kind of connections do you recommend? Keep it cheap. I am 1k in on this so far and dont really want to spend $300 on a connector box.

    I dont know what the risk of burning down a house with less than 1000w being separated between two inverters, but I promise i will be careful.
  • EstragonEstragon Registered Users Posts: 1,416 ✭✭✭✭
    Simple 6 breaker combiner box from our host $88.50 + 5 breakers @11ea. A midnite baby box for the breaker ahead of the inverter, $29 + ~15 for a breaker (it should also fit a 2nd breaker for your other inverter if they're close together). Fuses are a bit cheaper, but by the time you get holders, not that much. Breakers are also handier as disconnects than fuses. Max 15a breakers in the combiner box. The bigger one for the baby box depends on the wire size you end up using.

    40adc is nothing to sneeze at. DC will sustain an arc better than AC, which makes it more of a fire hazard.

    @WaterWheel - according to NAWS chart, 8ga is too small for the 40' run.
    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
  • OceanOcean Registered Users Posts: 39 ✭✭
    edited September 19 #28
    Just sayin, according to his diagram, each panel has it's own set of wires... but do they go all the way (40ft) from the panel to the inverter and then combine together?  Or, do they first combine and then run 40ft through 14/2?  If the latter is true, then yes, I would agree with @Estragon and @WaterWheel and the rest of the long run comments.  You need bigger wire.  Also, the manner in which you connect your panels together in parallel is important.  Wire nuts will not do for more than three individual wires.  At least get a couple of Bus Bars from the electrical section and use the screw terminals to secure each wire.  And yes, DC breakers!
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