Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 10-08-2009, 21:50   #1
Registered User
 
Down2TheC's Avatar

Join Date: Aug 2009
Location: Lake MI
Boat: Tartan 37
Posts: 83
ANL Fuse to Starter

Just did an electrical upgrade. When it came time for implementation, I balked at using the ANL fuse.
ABYC wants it between the alternator and the batteries... fine. But our Westerbeke has one lead from the engine to the battery compartment. It serves both directions. Charging from the Alternator and providing juice to the starter. Not sure I want to run my starter through a fuse. I have a 100Amp ANL which was fine for the Alt. but I see no documentation on what the starter potentially draws.

Any opinions? It's a Westerbeke 50 with a 40A alternator. I figure the thing hasn't fried itself in 28 years, it should be okay without it.
__________________

__________________
... and all I ask is a tall ship and a star to steer her by...
Down2TheC is offline   Reply With Quote
Old 10-08-2009, 22:34   #2
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
No, I don't think they require you to put a fuse there if it is the standard alternator charging the starter battery (but they do when you charge house batteries). Then again, I am no expert on ABYC. In fact, I think they impose no requirements at all, just suggestions.

I have 3 alternators on my engine: the standard one which charges the starter batteries (and uses the same cable as for starting) which has no fuse, and two extra ones that charge the house batteries, which do have a fuse each. And the boat has the ABS approval so I guess it's okay.

On a down to logic level: the wiring between starter battery (both positive and negative) and engine should be rated to easily carry the starter current and also easily carry the alternator output current. The alternator isn't going to output twice as much suddenly, but if you change to a high output alternator you might need bigger wires (which is forgotten sometimes).

Your 40A alternator doesn't sound like it could fry the cable that also starts the engine so you should be just fine without the fuse.

cheers,
Nick.
__________________

__________________
s/v Jedi is offline   Reply With Quote
Old 11-08-2009, 00:50   #3
Registered User
 
Down2TheC's Avatar

Join Date: Aug 2009
Location: Lake MI
Boat: Tartan 37
Posts: 83
That's my logic. Starter will certainly have the potential to draw more from the batts than the alternator could provide, so the OEM W50 cable was rated for the starter. And while I haven't dug for the schematics, I'd bet there's some fusible links built into the engine package in case of short or excessive starter draw.

So... anyone in the market for an ANL fuse?

I should mention, it's on a combiner so I'm charging both batts (2 T105's and a basic starter batt) anytime voltage breaks 13V.
__________________
... and all I ask is a tall ship and a star to steer her by...
Down2TheC is offline   Reply With Quote
Old 22-08-2009, 22:18   #4
Commercial Member
 
CharlieJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: St. Petersburg, FL
Boat: Gulfstar Long Range Trawler; 53'; BearBoat
Posts: 835
The reasoning behind requiring an over current protection device at both ends of the alternator/battery conductor is to minimize the amount of unprotected conductor exposed to out of specification current should the alternator short to ground or the battery fails internally.

In your case, I would recommend installing the ANL fuse on the engine stringer close to the B+ stud for the starter and run the output from the alternator to the fuse and then to the B+ stud. At least that portion of the conductor is protected from the conditions noted above.

Hope this helps.
Charlie
__________________
Charlie Johnson
JTB Marine Corporation
"The Devil is in the details and so is salvation."
CharlieJ is offline   Reply With Quote
Reply

Tags
fuses

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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 Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Fuse Box or Not? landonshaw Marine Electronics 16 10-07-2015 05:12
Calculating House Bank DC Fuse size. Pelagic Electrical: Batteries, Generators & Solar 1 28-07-2008 03:05
Starter fuse for outboard... Allan S Engines and Propulsion Systems 2 11-05-2008 19:27
Fuse between Battery(s) and Selector Switch Chief Engineer Electrical: Batteries, Generators & Solar 27 14-01-2008 17:25
Fuse Protection Ted Beyer Electrical: Batteries, Generators & Solar 5 17-05-2005 11:07



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 01:58.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.