Confused about Wire/Fuse sizes needed for Battery switch

bthessel

Cadet
Joined
Jun 21, 2010
Messages
22
So I am adding dual batteries to my boat. I bought a Blue Sea 7650 with the ACR and a bus bar. I am confused though about what gauge wire and fuses I need to use to connect it all. The diagram appears to show 4 fuses in the cables, 2 close to the batteries,one in the Accessory wire going to the switch, and one in the ground wire between the ACR and the bus bar.

If my engine/alternator is just the stock one in a 97 Maxum with the 4.3 how heavy of cables do I need if everything is going to be together in the back of the boat?


Also where do you find the large fuses and fuse holders? On the package it says 75A/90A for #6 wire. I have checked 3 auto parts places and none of them have fuses and holders that large.


Thanks in advance for any help.
 

minuteman62-64

Lieutenant
Joined
Apr 12, 2011
Messages
1,350
Re: Confused about Wire/Fuse sizes needed for Battery switch

I'm strictly a newby w/regard to boat wiring. However, I'd take a close look at that fuse in the ground wire. It's contrary to everything I've ever read/learned about any sort of wiring.
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
Messages
62,321
Re: Confused about Wire/Fuse sizes needed for Battery switch

About the fuse in the black wire for the ACR is explained here Fusing the Negative Circuit of ACRs and Other Electric Relays - Blue Sea Systems

Wiring sizes and fuse ratings for the ACR is found here Selecting the Appropriate Fuse Rating When Installing the 120A SI ACR - Blue Sea Systems

Large amperage fuse holders can be found here at iboats, auto parts stores probably don't have them.
Blue Sea Maxi Fuse Block - iboats

Have tried many BEP products in the past, not really impressed at all with them.
 

MH Hawker

Vice Admiral
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Jul 13, 2011
Messages
5,516
Re: Confused about Wire/Fuse sizes needed for Battery switch

I used a ATC fuse holder for 50 amps
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
Messages
62,321
Re: Confused about Wire/Fuse sizes needed for Battery switch

I used a ATC fuse holder for 50 amps

Probably would be a bad idea for him to use a 50A fuse with a 65A alternator.
 

MH Hawker

Vice Admiral
Joined
Jul 13, 2011
Messages
5,516
Re: Confused about Wire/Fuse sizes needed for Battery switch

Yes it sure would, I was talking about a 8 gage wire size. The ATC style holders go up to 75 amps I believe but not sure.
 
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