ACR Start Isolation Feature Question

Oct 26, 2008
6,045
Catalina 320 Barnegat, NJ
If you want to go from bank 1 to bank 2 the best pathway is through BOTH. No drop out of electronics and no blown diodes and the resultant transient to house loads if the alts still flows through the battery switch.
Yes, you don't want to go thru the "OFF" position instead. I've never heard about problems passing thru "1+2" to get to "2".
"Make then break" is the rule, right?
 
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
Even after reading all the posts on these battery switch topics, I missed the point that high starting currents can be carried across the ACR.
I learned this the hard way. The start battery wasn't charging. The fuse on the ACR lead to the start battery popped.

I will now have to wire the SI feature. :confused: (Even though it would be an extremely rare event when it would be necessary, it seems)
This really isn't that hard. It is one small wire (14-16 ga), fuse holder and a couple of connectors. The instructions say connect to the key switch. It can also be connected at the solenoid, which may be a shorter easier run.

Except for the alternator output, I am left wondering why we need the ACR, though. It seems that our battery charger (you now have the same one as mine) could simply be wired to both banks. But I guess when you consider the AO, we might as well leave it in place.
With an ACR, the charger only needs to be connected to the house battery. The ACR takes care of the rest. If the ACR and charger are wired to a positive bus bar, it will charge the start battery even if the house battery is out of service.
 
Oct 26, 2008
6,045
Catalina 320 Barnegat, NJ
If the ACR and charger are wired to a positive bus bar, it will charge the start battery even if the house battery is out of service.
Yes, this is how I'm wired. I was just ruminating that if I didn't use the ACR, then I could have isolation with my DCP without having to install the SI wire. :confused: It really goes to show how many options there are for wiring a system and how many ways you can :yikes:-up!
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
Thanks for this discussion, Ward. Even after reading all the posts on these battery switch topics, I missed the point that high starting currents can be carried across the ACR. I thought that by adding the 2 on-off switches with my DCP, that I finally had true isolation in both banks.

I will now have to wire the SI feature. :confused: (Even though it would be an extremely rare event when it would be necessary, it seems)
For smaller engines it would be very, very unlikely the 7610SI's relay would be damaged as they are really quite over-built. I have yet to see one fail due to this, but it never hurts to use it. As we get into larger engines, & dedicated starting banks, the SI feature becomes more relevant.
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
Yes, this is how I'm wired. I was just ruminating that if I didn't use the ACR, then I could have isolation with my DCP without having to install the SI wire. :confused: It really goes to show how many options there are for wiring a system and how many ways you can :yikes:-up!
If I had a dime for every boater who spent money on the Dual Circuit Plus / ACR kit, and did so because they expected "start bank isolation" and they failed to wire the SI feature and also had solar................ :wink: Suffice it to say you're not the only one to have not wired the SI feature with a DCP switch.
 
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
If I had a dime for every boater who spent money on the Dual Circuit Plus / ACR kit
But then you would be retired living in the tropics or perhaps the backwoods of Maine. And then where would we be?????:yikes:
 

Ward H

.
Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
To make this work correctly, each bank needs a separate on/off switch prior to feeding the DCP switch.
Adds one more too many switches. Trying to keep it simple and obvious to Admiral and guests.

Or just sail it back! :waycool:
Always my first choice. :biggrin:

There is NOTHING WRONG with passing through the BOTH position and you don't drop instruments or such by doing so...
That is what I didn't understand when I spoke of the "issue" in my other thread. Now I know its not an issue.

it prevents the high starting currents from being carried across the relay when you have alternative energy or are starting at the dock while still charging and the relay is in combine mode...
So there is a reason to wire it up. I'll do it.

no blown diodes and the resultant transient to house loads if the alts still flows through the battery switch.
Which is why I'm following your advice and wiring the AO to the positive bus bar at the house bank as well as all charging devices.

My goal in this upgrade is to make the system as bullet proof as possible while keeping it as simple as possible for all users.