Go Back  The Hull Truth - Boating and Fishing Forum > BOATING FORUMS > Marine Electronics Forum
Reload this Page >

Main fuse on battery terminal or after switch on +12v?

Notices
Marine Electronics Forum

Main fuse on battery terminal or after switch on +12v?

Old 02-27-2012, 08:49 AM
  #1  
Junior Member
Thread Starter
 
Join Date: Feb 2012
Location: Riverview, FL
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default Main fuse on battery terminal or after switch on +12v?

Continuing my project...

I am rewiring. I got some great advice regarding the use of a main fuse after the battery switch and before the run to the console fuse block. I then researched fuse types, and I've found 5 threads suggesting the use of a Blue Sea terminal fuse (pre-switch) and 5 threads suggesting a fuse after the switch. The ~7" from battery seems consistent though. Is there a consensus out there among you veterans? Thanks again guys/gals...I'm trying to do my due diligence prior to posting but there seems to be some difference of opinion.
Old 02-27-2012, 04:11 PM
  #2  
Senior MemberCaptains Club Member
 
Join Date: Dec 2007
Location: PBG, FL
Posts: 8,940
Likes: 0
Received 12 Likes on 12 Posts
Default

Usually a breaker after the switch will get the job done.
Old 02-28-2012, 04:59 AM
  #3  
Senior MemberCaptains Club Member
 
Join Date: Dec 2001
Location: Raleigh, NC. USA
Posts: 1,083
Likes: 0
Received 5 Likes on 4 Posts
Default

My setup has a 40 amp Blue Sea breaker installed just within a foot of the switch then goes up front to the main bus.
Old 02-28-2012, 05:24 AM
  #4  
Senior Member
THT sponsor
 
Join Date: Aug 2011
Location: Beaufort NC
Posts: 6,624
Received 3,316 Likes on 1,516 Posts
Default

ABYC guidelines call for circuit protection within 7" of the battery positive terminal with a couple exceptions allowed; a cranking motor lead (starter) doesn't "have" to have protection (but it is still a good idea). The other exception is if the wire is enclosed in a conduit or chase for chafe protection. If it is, up to 72" is allowed and believe it or not, split loom qualifies for this protection!

Unless it's a small engine, there aren't many breakers that will handle the current a starter motor will draw so a large ANL type fuse block is often used.


In most smaller console boats with a single battery, the battery hot lead goes to a nearby switch (with 2ga. wire), then the starter lead goes to the motor (with or more often without a fuse). A second larger (6 ga.) wire is then connected to a large waterproof breaker which then goes forward to the console along with a matching gauge ground lead.
Old 02-28-2012, 06:05 AM
  #5  
Junior Member
Thread Starter
 
Join Date: Feb 2012
Location: Riverview, FL
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks all... I've had my nose in the Boatowner's Illustrated Electrical Handbook by Charlie Wing (recommended on this forum somewhere) so I'm trying my best not to ask too much. I'm looking forward to this project now. To be honest I'm still not sure what protection I will use near the main switch, but it's becoming clearer the more I read. Thanks again.
Old 02-28-2012, 09:26 AM
  #6  
Senior MemberCaptains Club Member
 
Join Date: Dec 2001
Location: Raleigh, NC. USA
Posts: 1,083
Likes: 0
Received 5 Likes on 4 Posts
Default

Spot, here is a pic to give you a view of how it is rigged. This is factory: The breaker is the black box with red reset button to left of switch.
Attached Images  
Old 02-28-2012, 09:28 AM
  #7  
Senior MemberCaptains Club Member
 
Join Date: Dec 2001
Location: Raleigh, NC. USA
Posts: 1,083
Likes: 0
Received 5 Likes on 4 Posts
Default

Wait, found a better pic and closer up shot:
Attached Images  
Old 02-28-2012, 10:12 AM
  #8  
Junior Member
Thread Starter
 
Join Date: Feb 2012
Location: Riverview, FL
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default

Wow, awesome reference. Thank you. I like that simplicity.
Old 02-28-2012, 04:45 PM
  #9  
Senior MemberCaptains Club Member
 
Join Date: Dec 2007
Location: PBG, FL
Posts: 8,940
Likes: 0
Received 12 Likes on 12 Posts
Default

His is a 40 amp breaker. Make sure u have the right size breaker or fuse for ur boats use.
Old 02-28-2012, 04:50 PM
  #10  
Junior Member
Thread Starter
 
Join Date: Feb 2012
Location: Riverview, FL
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default

I will do... I'm still reading, then I'll do my calculations from there regarding fuse and wire sizes/lengths. Those Blue Sea battery mounted fuses just seem so simple, but I can see the sense in placing something after the switch. Thanks again everyone

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.