Trina Solar TSM-280 Series wiring question

latinhawk

I need 3 panels in series. However, the specs say Max Series Fuse 15a. My 3 panels together would be more than that. Should I use the fuses/breaker before combining or can I ignore that and use a 32a breaker after joining the string. Please see the picture of the panel babel attached.

mcgivor

When modules.are in series the voltage increases but the current remains the same, so use the recommended fuse or circuit breaker, 15A in this case.. 

latinhawk

Thanks.

Estragon

If you just have one or two strings, you don't really need OCP (fuse/breaker) on each string at all.  String breakers can be handy for troubleshooting though.  With three or more strings (or panels connected in parallel), OCP is needed to prevent a short in one string/panel from being fed the combined current from the remaining 2+ strings.  The 15a max OCP size is to protect panel wiring in this event.

You didn't mention whether the three panels are being connected as a series string (in which case @mcgivor is correct that current is the same as a single panel), or in parallel (in which case OCP is needed on each).  Depending on the application, one way or the other of wiring could be best.

Edit... missed the ref to series in your post

Where/if the strings are paralleled, current adds, so OCP should be added on the parallel to combiner circuit and sized to protect the chosen wire size on that circuit.