[C320-list] Alternator to batteries (FUSES)

[Jeff Hare]

Finding inline fuses that are large enough and still fit the inline fuse holders is a bit challenging.

We have a 60A Charles charger for our pair of AGMs.  Be sure that the inline fuses are each able to handle the full charge current.  Normally, the charger divides its current among all the connected outputs (C320 is factory wired for 2 charger outputs).  Current would be split between the two outputs, but if one blows, then the other leg will be able supply up to the charger's full rating and would then quickly blow the second.  Ask me how I know.  😊

We switched to using these.  $6  It's the highest rating in this form factor we could find anywhere. ...so far
Bussmann (BP/AGU-60GP-RP) Gold Plated 60 Amp Fast Acting AGU Fuse, (Pack of 2) 
by Bussmann 
Link: http://a.co/cP27rTV

-Jeff Hare

-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Warren Updike
Sent: Monday, March 27, 2017 8:13 AM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Alternator to batteries

Ahhh, someone I know rather well changed the shore charger from 20 to 40A and didn't know to increase the amperage of the fuses on the battery cables. That nearly crashed a cruise.

Battery fuses are now required/suggested by ABYC. Their purpose is not to protect equipment but to prevent melting cables in case of a direct short. These fuses are sized to the ampacity of the cable not necessarily the maximum load potential. Or so I'm given to understand.

Warren and Pattie Updike
1994 C320 "Warr de Mar" #62
Middle River, Chesapeake Bay

-----Original Message-----
From: B. Stumpp [mailto:bstumpp at comcast.net]
Sent: Sunday, March 26, 2017 3:28 PM
To: c320-list at lists.catalina320.com; tharrison at innovations-plus.com
Subject: [C320-list] Alternator to batteries

Ted, 

 

Reach under the settee where your batteries are and feel for an inline fuse in your positive (and negative?) cables a few inches from the terminals. 

One or all of these fuses are probably blown and need to be replaced.  

I've never seen inline fuses in battery cables fuses before, Catalina must put them there for some sort of boat manufacturer regulation.

Finding the fuses there is a surprise to a lot of people. 

I ran into the same problem a few years ago and couldn't figure out why my batteries were going bad when in fact they just were not charging.  

Found the problem by disconnecting both ends of the cables and doing a continuity test.  

Never understood why/how I blew these fuses but people have surmised it may have something to do with plugging into shore power. 

 

Bruce Stumpp

#647, Adventure

Frog Mortar Creek, Maryland

 

Message: 8

Date: Sat, 25 Mar 2017 11:53:23 -0400

From: Ted Harrison <tharrison at innovations-plus.com>

To: C320-List at Catalina320.com

Subject: Re: [C320-list] Alternator to batteries

Message-ID:

                <132D5517-84A0-4668-A8D3-DE38DAA7F042 at innovations-plus.com>

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I will get back to you on this one. Will go to the boat (on the hard) next weekend 

 

Thanks for your help. 

 

Ted Harrison