djacobs Posted June 27, 2016 Share Posted June 27, 2016 Hello All, I need some advice, on my Panels. I have 12 x 250w Panels, but in peak day I only get 1.5kw out of them, it seems that they are connected in pairs. Is there a reason for this. Regards Daniel Quote Link to comment Share on other sites More sharing options...
Energy-Jason Posted June 27, 2016 Share Posted June 27, 2016 Im sure the guys can help. Please do send us some pictures and a brief diagram of your system as well as components. Sincerely Jay Quote Link to comment Share on other sites More sharing options...
viper_za Posted June 27, 2016 Share Posted June 27, 2016 Hi djacobs As Jay said we need to know the rest of your components also to give some advice Quote Link to comment Share on other sites More sharing options...
djacobs Posted June 27, 2016 Author Share Posted June 27, 2016 Hi All, I have a 5Kw RCT inverter, 12 x 105ah batteries and 12 x 250w panels. I will upload some photos tomorrow. As far as what i can see is 6 x wires to one juntion box and then black out, and six wires with red out to inverter. Quote Link to comment Share on other sites More sharing options...
Energy-Jason Posted June 27, 2016 Share Posted June 27, 2016 Great Photos will help greatly. Jay Quote Link to comment Share on other sites More sharing options...
Guest Posted June 27, 2016 Share Posted June 27, 2016 12 x 25w panels, 2 x 250w connect in series, 6 stings in parallel. From panel to controller, having just been through such a questions, and having "lost" a panel once before due to wiring causing burnt out diodes on one panel, this are the most obvious ones to look for: Batteries, controller is not in float or absorption mode most of the time, with a small load? Shade during the day? Dirty panels? More complicated: Can you test each strings voltage? IF one string differs, focus on that strings panels by checking: Are all the connectors 100%? All the wires 100% and correctly wired? Are all the diodes still perfect? This is where I saw me bottom once before. Even more complicated, if all the above checks out: Start per string, see that each string gives you the same amps under load as the others do. Again, if once string is not doing so, then again focus on that strings panels. Quote Link to comment Share on other sites More sharing options...
viper_za Posted June 27, 2016 Share Posted June 27, 2016 For your inverter I would say the panels should be connected as 4 strings consisting of 3 panels in series per string. These would need to run to the combiner box. Each string will have two cables "+" and "-" running to the combiner box. In the combiner box the strings will be paralleled and will have a set of cables also "+" and "-" running to a isolator/ DC rated Circuit breaker and then to the PV inputs of the inverter. Then in the settings make sure option 31 is set to "sbe" : If selected, solar input power will be automatically adjusted according to the following formula:Max. input solar power = battery charging power + Connected load power Do not use "sbd" uses the following formula (Max. solar power = battery charging power) edmundp and Arandoza 2 Quote Link to comment Share on other sites More sharing options...
Arandoza Posted June 27, 2016 Share Posted June 27, 2016 Also to add to what viper just said maybe check what your maximum Mppt input voltage is? I have a Axpert 5kva and it's only 115 volt, some other folks seem to advise theirs is 145 volts of I recall correctly? Then check what the max Volts is on your panels and confirm that 3 in a string will not exceed the Mppt voltage. If you do it will damage the Mppt in the Axpert. Two other things to consider is that I have only seen my Axpert running at a reported - via LCD display - 2800 - 3600 watts or so and only from 10am to 2pm this winter, and when under load of around 2.3 kW output. If one is not using the load it stays very low around 1200 watts. viper_za 1 Quote Link to comment Share on other sites More sharing options...
viper_za Posted June 27, 2016 Share Posted June 27, 2016 2 minutes ago, Arandoza said: Also to add to what viper just said maybe check what your maximum Mppt input voltage is? I have a Axpert 5kva and it's only 115 volt, some other folks seem to advise theirs is 145 volts of I recall correctly? Arandoza you will see those are two separate ratings. If you look at your PV panels you should see two different voltage ratings. VMP: Maximum Power Voltage (This is the MPPT Voltage range, for the 5kva Axpert it needs to be 60-115vdc) VOC: Open Circuit Voltage (Max open circuit voltage on the 5kva, 145vdc) 7 minutes ago, Arandoza said: Then check what the max Volts is on your panels and confirm that 3 in a string will not exceed the Mppt voltage. If you do it will damage the Mppt in the Axpert. Yes please do this first Arandoza 1 Quote Link to comment Share on other sites More sharing options...
djacobs Posted June 28, 2016 Author Share Posted June 28, 2016 Hi Guys, Please note that I am totally an amateur with this and need a dummy guide.Thanks for you help this far. Here are some photos. Quote Link to comment Share on other sites More sharing options...
viper_za Posted June 28, 2016 Share Posted June 28, 2016 Who installed this for you? I see no fuses or DC breakers/ Isolators Does your battery bank have a fuse and isolator? By the looks of things your panels are connected in 6 strings of 2 panels each. Have you checked what option 31 is set to on the inverter? Quote Link to comment Share on other sites More sharing options...
djacobs Posted June 28, 2016 Author Share Posted June 28, 2016 Led Solar World (Bunch of Monkeys/ Idiots/ .............etc). They went bankrupt and still owe me money. No there are no Fuses or DC Breakers on everything. Option 31 is set SBE. Arandoza 1 Quote Link to comment Share on other sites More sharing options...
superdiy Posted June 28, 2016 Share Posted June 28, 2016 OK, looking at the "combiner boxes" it seems that you have 6 strings - I assume 2 panels in series per string. The Voc of 250W panels are about 38V per panel and the Vmpp is around 31V per panel, thus having two panels in series per string will give you a Voc of about 76V per string and a Vmpp of about 62V per string. Your inverter has a maximum PV input voltage of 145V and the MPPT will operate with a voltage between 60 and 115V. Say you have a bright sunny day in summer and an irradiance of 1000W per m2, low ambient temperature and the sun hitting the panels at 90° you should get about 62V per string, but since it is winter, with probably a much lower irradiance than 1000W per m2 and the sun not hitting the panels at 90° all the time you should seldom reach anything close to 62V per string and therefor the MPPT in the inverter will probably never work at all. As mentioned earlier in this thread the ideal PV array using your existing panels would be in a "4 parallel strings of 3 panels each connected in series" configuration - that would give you an open circuit voltage of about 114V, which is much lower than the maximum input voltage of 145V on the inverter and under ideal conditions the panels will produce a max power point voltage of about 93V per string which is well within the MPPT range of the inverter (60V - 115V). So what it comes down to is to re-wire the panels in a 4 x 3 configuration and while you do that add a fuse per string as well (if you currently don't have any installed) (PV string fuses are usually installed in the combiner boxes and your's do not have any installed). viper_za and ___ 2 Quote Link to comment Share on other sites More sharing options...
viper_za Posted June 28, 2016 Share Posted June 28, 2016 15 minutes ago, superdiy said: So what it comes down to is to re-wire the panels in a 4 x 3 configuration and while you do that add a fuse per string as well (if you currently don't have any installed) (PV string fuses are usually installed in the combiner boxes and your's do not have any installed). 100% with a Isolator for the PV also. Then next step is to add a fuse and isolator to the battery bank superdiy 1 Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted June 28, 2016 Share Posted June 28, 2016 eish. Hopefully you don't have blown diodes. Fuses are there to protect the cables and panels in case of faults. 2 panels per string would be within the safe MPPT Voc but I would still run fuses. Use 12A fuses on these panels. Also, if the battery bank is full, the panels "draw" will be less. i.e. you will only see full draw on an empty battery bank, or with heavy load for more than 10 minutes. Quote Link to comment Share on other sites More sharing options...
djacobs Posted June 28, 2016 Author Share Posted June 28, 2016 Ok ok is there somebody that can do this for me. Yes I will pay. All I need is for this to get sorted out. I have been raped by chancers and now I am payimg for it. Please let me know. Thanks all. Quote Link to comment Share on other sites More sharing options...
Chris Hobson Posted June 28, 2016 Share Posted June 28, 2016 Silver is an installer in the Gauteng area. ___ 1 Quote Link to comment Share on other sites More sharing options...
Guest Posted June 28, 2016 Share Posted June 28, 2016 3 minutes ago, djacobs said: ... is there somebody that can do this for me. Yes I will pay. All I need is for this to get sorted out ... Danie, ek VOEL jou pyn. Wat amper meer pynlik is ne, is om iemand te kry om dit te kom doen vir jou. Dis soos om hoender tande te trek. Jy kry net NIKS reg. Quote Link to comment Share on other sites More sharing options...
djacobs Posted June 28, 2016 Author Share Posted June 28, 2016 Ek is gerape Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted June 28, 2016 Share Posted June 28, 2016 31 minutes ago, djacobs said: Ok ok is there somebody that can do this for me. Yes I will pay. All I need is for this to get sorted out. I have been raped by chancers and now I am payimg for it. Please let me know. Thanks all. Hi, I'll send you a PM. Cover my petrol and I'll come check it out and make recommendations and you can then decide Fritz and Chris Hobson 2 Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted June 28, 2016 Share Posted June 28, 2016 27 minutes ago, The Terrible Triplett said: Danie, ek VOEL jou pyn. Wat amper meer pynlik is ne, is om iemand te kry om dit te kom doen vir jou. Dis soos om hoender tande te trek. Jy kry net NIKS reg. Dis nie my skuld jy bly in die Kaap nie.... ___ 1 Quote Link to comment Share on other sites More sharing options...
Guest Posted June 28, 2016 Share Posted June 28, 2016 Sien Danie, sorted. Quote Link to comment Share on other sites More sharing options...
superdiy Posted June 29, 2016 Share Posted June 29, 2016 11 hours ago, SilverNodashi said: 2 panels per string would be within the safe MPPT Voc but I would still run fuses. Also, if the battery bank is full, the panels "draw" will be less. i.e. you will only see full draw on an empty battery bank, or with heavy load for more than 10 minutes. Yes, 2 panels per string would be within the safe MPPT Voc, BUT the voltage would be to low for the MPPT to work 99% of the time. If the MPPT cannot do its thing, you essentially waste power. Yes, when the batteries are charged and the load is low, you are not going to use the power in any case, BUT when the batteries are not charged and/or the load is high enough to make use of all the available power from the panels, you will have less available power using 2 panels per string than what you would have with 3 panels per string and the MPPT doing what it is designed for. The Voc of 3 panels per string is still well below the max PV input voltage of the inverter, so no worries there. viper_za and Chris Hobson 2 Quote Link to comment Share on other sites More sharing options...
subok01 Posted July 30, 2016 Share Posted July 30, 2016 Djacobs, contact MLT power in Midrand. They will sort you out. Solar System Designer and IT Systems Auditor Quote Link to comment Share on other sites More sharing options...
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