Thanks for the complete and thorough response. Dave.
Sent from my iPhone > On Aug 30, 2021, at 7:57 AM, Riley Anderson via CnC-List > <cnc-list@cnc-list.com> wrote: > > > Just to clarify some of the half answers posted previously: > > The wires from the panels to the charge controller must be sized to handle > the short circuit current of the entire array (additive if parallel array). > Because the maximum current under normal conditions is often ~95% of short > circuit current, it is essentially impossible to fuse this side with the > industry standard 25% safety factor without having the fuse blow prematurely > under normal conditions. > > The most critical fuse/breaker is on the battery side of the charge > controller as the battery bank has a much larger potential to dump high > current in a short circuit. This fuse/breaker should be mounted to the charge > bus (if available) or as close as possible to the battery. > > However, it is not a bad idea to have a dual pull breaker between panel and > charge controller sized at 10-15% > short circuit current. The main purpose > of this breaker is to be able to safely disconnect the panels for maintenance > or replacement. > > To the original poster: > How large is your battery bank and how old is it? Lead acid or gel? How large > is the solar panel? > > Knowing these paramater can help us narrow down the likely problems. > > My guess, is that the most likely cause is you had days of cloudy skies after > the hurricane and weren't getting any charge. Or your battery bank may be > small or aging and unable to accept a trickle charge anymore. > > >> On Sun, Aug 29, 2021, 8:44 PM Dave S via CnC-List <cnc-list@cnc-list.com> >> wrote: >> My 175w and 50w are fused for the gauge of the cable, directly adjacent to >> the controller. This is per the renogy manual I believe. 12 awg solar >> cable would be likely fused at 20a (assumes 105deg rated insulation) which >> at our 20vdc would translate to a BIG 400w panel. (C&C 65?) These bigger >> panels are typically 48vdc I believe so the current stays modest. anyway - >> no need to fuse at the solar panel. >> >> The batteries are connected in parallel with copper bus bars and the >> positive wires are protected with cube fuses at the battery. (Both solar >> and shore power Chargers and the cables to the battery switch) >> >> Dave 33-2 >> >> Dave >> >> Sent from my iPhone >> >>>> On Aug 29, 2021, at 7:47 PM, Marek Dziedzic via CnC-List >>>> <cnc-list@cnc-list.com> wrote: >>>> >>> >>> I have that end covered. Proper fuses right at the battery terminals. And >>> the solar panel is tied to the controller, not the batteries themselves. >>> But there is some 25’ of cable from the panel to the controller and I >>> always wonder if that part should be protected as well. The solar panel is >>> only 50 W, so it cannot produce too much current (and too much heat). But I >>> wonder what it the proper way to connect it and protect it. >>> >>> >>> >>> Marek >>> >>> >>> >>> From: Ken Heaton via CnC-List <cnc-list@cnc-list.com> >>> Sent: Sunday, August 29, 2021 6:26 PM >>> To: Stus-List <cnc-list@cnc-list.com> >>> Cc: Ken Heaton <kenhea...@gmail.com> >>> Subject: Stus-List Re: Another Solar question >>> >>> >>> >>> Really, should there be a short or other electrical failure, the big source >>> of current that would heat up and burn up the wires and possibly set the >>> boat on fire, would be the boat's house or starting battery bank. So the >>> fuse should be as close as possible to where the wires from the solar >>> panels tie into larger wires or bus bars (or the batteries if wired direct >>> to the battery bank). As close as 6 inches if possible. >>> >>> >>> >>> Ken H. >>> >>> >>> >>> On Sun, 29 Aug 2021 at 19:19, Marek Dziedzic via CnC-List >>> <cnc-list@cnc-list.com> wrote: >>> >>> I have a simple question - the fuse is there to protect the wire; so, the >>> fuse should be as close to the solar panel as possible, shouldn't it? Where >>> would you put it? Outside, next to the panel? Or inside, as soon as the >>> wire goes through the deck? >>> >>> >>> >>> I bet there are some rules of thumb. >>> >>> >>> >>> Thanks >>> >>> >>> >>> Marek >>> >>> 1994 C270 Legato >>> >>> Ottawa ON >>> >>> >>> >>> >>> >>> Thanks to all of the subscribers that contributed to the list to help with >>> the costs involved. If you want to show your support to the list - use >>> PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - >>> Stu >> Thanks to all of the subscribers that contributed to the list to help with >> the costs involved. If you want to show your support to the list - use >> PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - >> Stu > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
Thanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
