Posts : 47 Join date : 2014-08-07 Age : 50 Location : Hong Kong
Subject: Off Grid Solar Combiner Thu Aug 07, 2014 4:03 pm
It is not easy finding a combiner box for off grid systems using 12v or 24v battery banks. Everything seems to be made for grid tied systems with voltages up to 600v.
I live on the power I make, and have no care to sell back any power at a fraction of what an electric company would charge me to buy from them... seems pointless to me !
My solar charge controllers (MorningStar TS-60 MPPT or PWM) are rated at 60 amps, and thus require a combiner box for each array of 50A to 60A with lightening protection at each. Each controller is set to one voltage... 12v or 24v, so the Lightening protection should be set to that voltage... I have either a 12v or a 24v SPD in each box. That will dedicate the set voltage for each combiner.
Every DC breaker I can find is rated at 250v... I need nothing that high... 48v DC would be the maximum... so I have to have them made. Found a reliable factory, and here they are ! I want to break both the negative and positive for total isolation, should I require the need to do any maintenance or repairs, as well as isolate the entire array at now breaker !
I am very happy living off grid, and although the majority see earning fractions of pennies for power they can sell to an electrical utility company worth it. Living off grid for me, gives full payment for what power I make !