Marine System Check. Tripping Combiner Box

[flackbrandon]

Hi all, thanks for any and all help or advice. We have 10 panels in 4 strings (3,3,2,2) wired up in parallel. We have significant shading issues wirh the sail stored and rarely get more then 40 amps out of the 12v 60 amp charge controller (our best days are about 240 ah in total).

Still once a week or so we are tripping the circuit breaker in the 63a combiner box? Specs below - any suggestions welcome!

1- OutBack Power FM60-150VDC FLEXMax 60 Charge Controller



1 - Solar Combiner Box PV Combiner Box 4 String With15A Rated Current Fuse Solar DC Breaker



10 - Renogy Solar Panels 100 Watt 12 Volt, High-Efficiency Monocrystalline PV Module Power Charger

 

[wpns]

I'm not sure I understand your configuration, you have 3S, 3S, 2S, 2S all wired in parallel to a single MPPT input?

Your topic says tripping combiner box but your text says charge controller?

 

[flackbrandon]

Yes on the wiring. Sorry, we are tripping the combiner box 63a breaker - revised original post.

Breaker tripping is orange one in photo.

 

[mikefitz]

suggestions welcome!

Any strings in parallel need to have the same total volts. With 10 off 100 watt panels, Voc 24.3, you can have two strings of 5 panels in series, three strings of 3 panels in series, five strings of 2 panels in series.
The four strings you have, are in effect, two panel strings.
A 63 amp breaker should handle 20 amps of 4 strings, is it rated for DC ?

With shading on a sailboat, seperate controllers for each strings can deliver more yield. A suggestion is to use two panel strings and Install 5 Victron Smart 75/15 controllers.

 

[wpns]

Yes on the wiring. Sorry, we are tripping the combiner box 63a breaker - revised original post.

Breaker tripping is orange one in photo.

4 strings at Isc of 5+ amps isn't going to trip a 63A breaker, is it possible the breaker is defective? The SCC has a log, can you tell what the solar input current was just before it tripped?

What size are the fuses in the combiner box?

 

[flackbrandon]

Any strings in parallel need to have the same total volts. With 10 off 100 watt panels, Voc 24.3, you can have two strings of 5 panels in series, three strings of 3 panels in series, five strings of 2 panels in series.
The four strings you have, are in effect, two panel strings.
A 63 amp breaker should handle 20 amps of 4 strings, is it rated for DC ?

With shading on a sailboat, seperate controllers for each strings can deliver more yield. A suggestion is to use two panel strings and Install 5 Victron Smart 75/15 controllers.

Like this idea... and if we went to 12 panels we would could just add one more. Does this mean we can take out our combiner box and outback mppt unit?

 

[flackbrandon]

These are the fuses we have in the current combiner box.

 

[mikefitz]

Does this mean we can take out our combiner box and outback mppt unit?

Yes, no series solar fuses are required, an isolator on each string would be useful. All controllers connect to the battery bank with suitable fuses/breakers for each controller positive feed cable. With two panel strings a 75/15 is needed. With three panel strings a 100/20. With the Victron Smart controllers its easy to see instant and daily total string yield via the Victron app.

 

[wpns]

These are the fuses we have in the current combiner box.

Those are the fuse HOLDERS you have. Turn off the breaker and pop one (or all) of the fuses out and see what size they are.

 

[HarryN]

Breaker might be defective, or you could be getting reverse current back into the solar panel arrays that are lower voltage. ( damaged panels ) Difficult to know.