|
05-24-2011, 11:00 AM
|
#1
|
Guru
Join Date: Nov 2009
Posts: 649
|
Fuse on starting battery
I put a fuse holder on my starting battery with a 200 amps fuse. The fuse blew right away. What size fuse would I need? 300 amps? Do you have a fuse on your starting battery?
|
|
|
05-24-2011, 12:39 PM
|
#2
|
TF Site Team
City: Jacksonville
Join Date: Nov 2008
Posts: 11,682
|
RE: Fuse on starting battery
Hobo's starting battery is fused with a 400amp, Class T fuse.
|
|
|
05-24-2011, 06:49 PM
|
#3
|
Grand Vizier
Join Date: Jan 2010
Posts: 3,816
|
RE: Fuse on starting battery
You should be able to find out the inrush current for the starter, and that will guide the selection of the right fuse. *Here's a source I use:
*
http://amplepower.com/products/fuses/index.html
|
|
|
05-25-2011, 02:41 AM
|
#4
|
Guru
Join Date: Oct 2007
Posts: 22,553
|
RE: Fuse on starting battery
I can understand a really heavy duty switch ,(see Practical Sailor) but why a fuse?
The most common failure is probably the starter bendex sticking , and the spinning starter throwing 100V or more into the vessels electrical system .
A switch will stop it , or a starter fire , but a fuse works on Amps , so probably wont mind a bit.
|
|
|
05-25-2011, 07:40 AM
|
#5
|
Guru
City: Everett Wa
Vessel Name: Eagle
Vessel Model: Roughwater 58 pilot house
Join Date: Oct 2007
Posts: 2,919
|
RE: Fuse on starting battery
When we bought the Eagle already had a 500 amp fuse, which we blew the fist time we took the boat out as we changed the filter and got air in the lines, cranking the 671.* The engine ran long enough to get out of the marina and died.* Being a newbie did not know diesel do not like air in the fuel lines.* Luck would have it the wind blew us right into the Lake Union Police marina, which they of course got all excited.* However, they were nice enough to have their mechanic bleed the engine and find the fuse, so we would get off THEIR DOCK.*
|
|
|
05-25-2011, 08:01 AM
|
#6
|
Guru
Join Date: Jun 2008
Posts: 5,037
|
RE: Fuse on starting battery
Quote:
FF wrote:
The most common failure is probably the starter bendex sticking , and the spinning starter throwing 100V or more into the vessels electrical system .
|
*This happened to one of the boats (40 Viking)*on our dock last summer. One of the twin*Detroit 6-92 450s. The owner ran the boat about an hour + with the starter engaged. Did not know, couldn't hear the starter, but the exhaust sounded "funny". Did not*overload boat's electrical system except for burning up the starter.
*
|
|
|
05-25-2011, 08:25 AM
|
#7
|
Guru
Join Date: Nov 2009
Posts: 649
|
RE: Fuse on starting battery
Thanks. The more I think about it the more I don't see why I would put a fuse on the starter battery.
|
|
|
05-26-2011, 02:50 AM
|
#8
|
Guru
Join Date: Oct 2007
Posts: 22,553
|
RE: Fuse on starting battery
A second problem is many alternator outputs simply go to the starter terminal.
Its close , and the wiring is always ample to handle the alt output.
Should a fuse disconect an operating alternator its usually diode time.
Have the press and spare diodes aboard?
A good rotary switch and proper wiring solves this.
There is (on a good rotary switch) an alternator field power terminal.
It breaks the alt field before disconnecting the selected batt.
Connects the batt , then powers the alt , when selecting a batt.
GREAT INSURANCE , if your alt is hooked to the starter.
IF someone were to go to the trouble of rewiring to install a field disconnect switch , I would add a manual switch in the event of V reg failure, with the chance of over voltage charging, boiling battsets.
|
|
|
05-26-2011, 09:17 AM
|
#9
|
Guru
City: Everett Wa
Vessel Name: Eagle
Vessel Model: Roughwater 58 pilot house
Join Date: Oct 2007
Posts: 2,919
|
RE: Fuse on starting battery
The reason you might is I beleive its ABYC standard.* We had an insurance audit that went through the Eagle from the*bow to the stern and had to bring the Eagle up to ABYC standard.*
|
|
|
05-26-2011, 07:02 PM
|
#10
|
Senior Member
City: Anacortes, WA
Vessel Name: Thea
Vessel Model: 46 Grand Banks Classic
Join Date: Oct 2007
Posts: 280
|
RE: Fuse on starting battery
ABYC 11.10.1.1* exceptions to overcurrent device requirements:
1.* Cranking motor conductors
|
|
|
05-26-2011, 08:12 PM
|
#11
|
Guru
City: Concrete Washington State
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 18,743
|
RE: Fuse on starting battery
We have a 500 amp fuse in our starting motor circuit. Just noticed it last week and wondered what it was for. Maybe the fuse is viewed as a safety switch so when someone lays a wrench across the terminals the fuse limits the time of extreme current. Could be fire safety. How hot would a battery cable get w over 500 amps going through it?
|
|
|
05-27-2011, 03:10 AM
|
#12
|
Guru
Join Date: Oct 2007
Posts: 22,553
|
RE: Fuse on starting battery
How hot would a battery cable get w over 500 amps going through it?
Depends on how thick the cable actually is.
|
|
|
05-27-2011, 05:42 AM
|
#13
|
Guru
City: Cruising East Coast US
Vessel Name: Grace
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 2,420
|
RE: Fuse on starting battery
Don't fuse the starting battery, disconnect switch yes, fuse no.
|
|
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Trawler Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|