A Forum run by Enthusiasts of MidNite Solar

PV Combiners => Standard non-disconnecting PV Combiner Discussion => Topic started by: gordo on April 19, 2012, 12:01:49 AM

Title: combining combiner boxes
Post by: gordo on April 19, 2012, 12:01:49 AM
howdy . my name is gordy live in east idaho.  off the grid 500watt array and tracker from 1985.  outback 3524/flex max 80. 

so i have a mnpv6 combiner on my tracker and i have another tracker with about 10 functioning 50watt panels that i would like to hook up cause there just sitting there.  can i buy another mnpv6 and run some mc up to the current one or should i buy an mnpv12? 

thanks
Title: Re: combining combiner boxes
Post by: vtmaps on April 19, 2012, 06:45:38 AM
gordy, Welcome to the forum.   We need more info to answer your question. 

How many panels are you using now, what are their specs, and how are they combined (number of strings)? 

Regarding your unused panels, how many (you wrote 'about 10') and what are their specs?

How far apart are the two arrays?  How far are they from your FM80?  Will both arrays have identical exposure to the sun?

--vtMaps
Title: Re: combining combiner boxes
Post by: gordo on April 19, 2012, 10:52:44 AM
vtmaps-  12/ 43 watt arco panels (also mid 80's), 2.5 amp.    80 ft from fm80  3/0 wire.  arrays would be about 10 ft apart.  exposure will vary.  one array is on a tracker.  other would be fixed.  i can see the two varied exposures being a problem for max solar gain.  where the tracker would be canceled or reduced output to match the fixed array.  i have another tracker just don't have the money for another tower?  any input to connect my remaining 10 panels to use would be great.  they are the same specs as the array on the tracker.

cheers gordo
Title: Re: combining combiner boxes
Post by: vtmaps on April 20, 2012, 05:48:26 AM
Gordo, I still don't understand how your 12 panels on the tracker are wired or their specs.  What voltage are they? Are all 12 panels in series, in parallel, or do you have three parallel strings of 4 panels each, 6 parallel strings of 2 panels each, 2 parallel strings of 6 panels each, 4 parallel strings of 3 panels each?
--vtMaps
Title: Re: combining combiner boxes
Post by: Robin on April 29, 2012, 05:17:47 PM
The busbar in your MNPV6 is good for up to 120 amps, so disregarding all other issues, you can combine two MNPV6's as long as the short circuit current is 120 amps or less. This is why we include two box lugs with each MNPV6. The MNPV12 has 200 amp busbars.