[C320-list] Fuses at the 3rd Battery

[crashley at gte.net]

Jeff,

Interestingly, I found that the red 1/0 sized wire from the battery selector 
switch (common) to the starter solenoid (on the engine) was actually 
connected DOWNSTREAM of the 135A breaker next to the battery switch, the 
same breaker that feeds the DC distribution panel. The Catalina wiring 
diagram shows it connected to the common of the battery selector switch, so 
I moved it there. It was actually a little difficult to do with the 1/0 size 
wire, which is maybe why it was connected where it was. I plan to put a 200A 
in line fuse on that line behind the battery switch in case a short to 
ground develeops in the solenoid for some reason (I know it shouldn't happen 
but that's what fuses are for, right?) I've been sort of upgrading my DC 
system and plan to post some details on the site when I'm done.

CRA
Rosebud #882

----- Original Message ----- 
From: "Jeff Hare" <catalina at thehares.com>
To: <C320-List at Catalina320.com>
Sent: Friday, February 15, 2008 2:50 PM
Subject: Re: [C320-list] Fuses at the 3rd Battery


>I believe he's referring to a fuse on the charging line leading from the
> charger to the battery.  That way if the charger develops a short the fuse
> will blow.
>
> As you suspected, you would really not want a fuse in line with the 
> starter.
> That cable should be bolted in place at both ends and we "expect" them to
> stay bolted in place or bad things are guaranteed to happen.  :)
>
> I mentioned earlier, if you really want to protect the battery and all the
> load circuit wiring from all grossly abnormal loads, get a large 250 Amp
> terminal block Fuse.  Lead a jumper from the GROUND of your battery bank
> through this fuse and then connect any ground return cables the other side
> of the fuse.
>
> This is, surprisingly, safer and much easier than trying to Fuse the
> positive side of the battery (given all the things that tend to tap into 
> the
> battery positive side). Electricians tend to Look for a Ground anywhere 
> they
> can, but are strangely more particular about where they source their power
> from.
>
> -Jeff
>
> PS:  As an interesting side note,  I was working on a boat a year or so 
> ago
> that had some really bizarre electrical system quirks.  You'd key the mic 
> on
> the VHF or Sideband and the chart plotter would reset.
>
> What was happening was that the P/O was careful to feed properly sized 
> +12v
> lines from the battery, but just jumpered over to whatever Ground 
> connection
> was close to the area, assuming that they all lead back to the same place.
> Well, they did.  Just that in one place, they all funneled through a short
> 8" section of 14 gauge wire.  Apparently an old power hungry piece of
> equipment got removed, along with its hefty power and ground wires.  But
> that ground had begun serving as the load return for a bunch of other 
> things
> added over the years.
>
> Moral of the story:  If you have to add a wire to power something, be sure
> to provide at least the same gauge of wire back to a PROPER ground bus, 
> not
> just a place that looks like ground to your volt meter.
>
>
> -----Original Message-----
> From: c320-list-bounces at lists.catalina320.com
> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of
> crashley at gte.net
> Sent: Friday, February 15, 2008 8:58 AM
> To: C320-List at Catalina320.com
> Subject: Re: [C320-list] Fuses at the 3rd Battery
>
> One comment, the starting battery shouldn't be fused so low that the 
> starter
>
> will blow the fuse (duh), not sure what that fuse rating needs to be but 
> 40A
>
> sounds a little low.
>
> CRA
> Rosebud #882
>
> ----- Original Message ----- 
> From: "Jon Vez" <jonvez at comcast.net>
> To: <C320-List at Catalina320.com>
> Sent: Friday, February 15, 2008 5:27 AM
> Subject: Re: [C320-list] Fuses at the 3rd Battery
>
>
>> Bruce,
>>
>> All batteries should be fused...you can use the same as you did for your
>> house bank...
>>
>> Regards,
>>
>> Jon
>>
>> -----Original Message-----
>> From: c320-list-bounces at lists.catalina320.com
>> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Bruce
>> Stanley
>> Sent: Thursday, February 14, 2008 10:25 PM
>> To: C320-List
>> Subject: [C320-list] Fuses at the 3rd Battery
>>
>> C320 #1084 has 40 Amp fuses, 7" from the 2x4D batteries.........as now
>> installed by Catalina.
>>
>> Question:
>> should I have installed a FUSE, 7" from my new 80amp Starting
>> Battery?????????
>> Should it be 40 Amp?
>>
>> I followed the 3rd Starting Battery Tech notes (as on the C320IA site),
>> but
>> I do not recall installing a Fuse at the Battery.
>> I am a bit worried. We will be back on board, this afternoon.
>>
>> thanks in anticipation.
>>
>> Bruce Stanley #1084
>> Sydney Australia
>>
>>
>
>
>