[C320-list] In-line fuse on battery cables

[kendgb]

Sara, I think the online fuses that you are referring to are on the charging cables from the charger to the batteries.  One each bank as Dean says and on our 2000 #765 they are 30 amp as shown on the Catalina 320 wiring diagram.  I have recently found one blown for unknown reasons.  The fusing size relates to the wire size being used so you should figure out that size before you go to a larger fuse.  Again see if the wiring diagram is of any help.I wonder about your charger putting out 40 amps but others will know better.Good luckKenNorthern Dream Sent from my Samsung Galaxy smartphone.
-------- Original message --------From: dean at vermeire.us Date: 2020-09-14  12:53  (GMT-05:00) To: C320-List at Catalina320.com Subject: Re: [C320-list] In-line fuse on battery cables    I recently installed a new ProNautic 1230P (30A) and have the original   configuration of 2 4D batteries with one on each bank. The inline fuses   on mine are 30A.   Everything is working great.   Since your charger will automatically adjust the amperage up to 40A on   a bank, I would think a 20A fuse would be easy to blow.   On Sep 14, 2020 11:33 AM, SARA SCHROEDER <saras951 at comcast.net> wrote:     I had reached out to the group regarding recommendations on battery     charges, echo-chargers and solar panels.  As a reminder I have two     4D deep cycle batteries, did not have a starter battery or     echo-charger and my batteries were either not being fully charged or     were losing capacity. After doing research, my helper and I ganged     the two 4D batteries together into one house bank which became bank     #1 and installed a new starter battery which became bank #2.  We     also installed a new ProMariner ProNautic 12V 40 AMP battery     charger.     After a full weekend away from the dock, this set up turned out to     be an epic failure.  The batteries were not being charged at all -     either by the new charger or the alternator.  Upon further     inspection we discovered that both the alternator and the new     charger were blowing the 20amp in-line fuse located in the positive     battery cable. We considered just putting in a larger fuse but Platt     Electric recommended we not do this.     We undid everything and reverted back to the factory settings.  One     4D is back to house bank #1 and the second 4D is house bank #2.  The     starter battery and echo-charger are on hold for the moment.  We     installed new fuses in both positive cables, fired up the new     battery charger and my batteries finally started getting a charge.     At first the ProNautic was pumping in about 40amps but this quickly     came down to about 20amps.  After about 30 minutes of charging my     helper reached down and touched the in-line fuse casings. They were     shockingly hot. We could not really even touch them.  I stayed at     the boat to monitor them and after about 3 hours I could touch them     and the cables themselves were "slightly" warm but not hot.     I suspect the fuse housings are original which makes them 20 years     old.  Does anyone have these round in-line fuse housings or is it     just me? Have you had problems with them failing or replaced them?     If you replaced them what did you use?  Thanks as always!     Sara     Wandering Star     2000 / #707