ANL fuses on batteries

Maine Sail · Dec 26, 2013

c130king said:
Sitting on Polaris this cool day getting ready to go sailing. During engine start I blew the ANL fuse on battery 1. It had an 80 amp fuse.

Replaced this fuse back in March when I got my new batteries and seem to recall the previous fuse was 130 but not positive about that. Seem to recall that all the shop had was 80s so we went with it.

The fuse on battery 2 has worn off printing so I can't read it.

Can anyone help me out on determining proper amp fuse?

I have 2 x group 4 marine batteries.

Thanks and Merry Christmas!

Cheers
Jim

What guge wire..? If starting an engine you will want 250 - 300A but this will depend on wire size..

Long Story · Dec 26, 2013

The Wiring Diagram I have (Catalina) shows a 250 AMP fuse, and 2/0 cable. Maine Sail can advise if that makes your fuse or your cable the "weak link" (you want the fuse to be)

Maine Sail · Dec 26, 2013

If he has 2/0 than I would definitely go with 300A...

JK_Boston_Catalina310 · Dec 26, 2013

The Catalina 310 came from the factory with 2/0 gauge wire for the batteries. I had 150 amp on mine from my PO. After consulting with Mainesail and a sizing chart I had upped to 250 amp and had no issues.

paulj · Dec 26, 2013

c130king said:
Back at the house. Sailing today went just fine...but only used Battery 2.

I did learn...at the end of the day...that my bilge pump is wired through Battery 1. I had the switch in "2" for about 3 hours and at the end of the day when I turned the switch to "All" momentarily the pump kick on because the water had risen some in the bilge. In "2" the pump didn't work. Battery "1" was not providing any power due to the blown fuse. But this is a different subject.

I am not sure of the size of the wire. My neighbor guessed 1/0. I can see the harm of selecting a fuse with too high of an amperage...the wire could overheat before the fuse blows.

But is there any harm of having too small of a fuse other than the fuse may blow too often? I think I had a 130 and went with an 80. The 80 has worked for about 8 months with no issue but today with cold engine and extended "preheat" and extended "starter" waiting for engine to catch...the fuse blew.

I am leery of going with a 250 or 300 amp fuse as I am not sure of my wire gauge.

Thoughts???

Thanks,
Jim

c130king

My small bilge pump is wired to battery all.

My thought...........

So much for the fuse .....how was the sailing?

paulj :troll:

Maine Sail · Dec 26, 2013

c130king said:
Back at the house. Sailing today went just fine...but only used Battery 2.

I did learn...at the end of the day...that my bilge pump is wired through Battery 1. I had the switch in "2" for about 3 hours and at the end of the day when I turned the switch to "All" momentarily the pump kick on because the water had risen some in the bilge. In "2" the pump didn't work. Battery "1" was not providing any power due to the blown fuse. But this is a different subject.

I am not sure of the size of the wire. My neighbor guessed 1/0. I can see the harm of selecting a fuse with too high of an amperage...the wire could overheat before the fuse blows.

But is there any harm of having too small of a fuse other than the fuse may blow too often? I think I had a 130 and went with an 80. The 80 has worked for about 8 months with no issue but today with cold engine and extended "preheat" and extended "starter" waiting for engine to catch...the fuse blew.

I am leery of going with a 250 or 300 amp fuse as I am not sure of my wire gauge.

Thoughts???

Thanks,
Jim

Whether you have 1/0 or 2/0 you can still use a 250 or 300.. Remember the fuse protects the wire, fuses can cause voltage drop thus the best fuse is usually the largest that can be fitted, especially with starting motors and battery bank fusing..

Maine Sail · Dec 26, 2013

c130king said:
The sailing was very nice. Temps in the low 50's with winds around 7-10. Cloudy but we got a sunset when the sun got low enough. And we had a few dolphins checking us out. Mississippi Sound is nice sailing most of the time.

The boat looks great...new polishing and wax job. And is running great except for a few minor issues:

1) the aforementioned ($0.50 word alert) ANL fuse...and...

2) I now have a "squeal" between about 1300 - 1800 RPM. Idle around 1000 and max at 2500. Did not have the squeal before the boat went into the yard a few weeks ago. Suspect the cutlass bearing...but my friend and I aren't 100% positive on that. Prop and shaft are now much cleaner...numerous barnacles before being sand blasted. I had no zincs...one put on in Summer was gone (no trace). Have 2 1" zinc footballs now. And now there is paint on the exposed shaft and prop. Yard manager told us that cutlass bearing could dry out and the squeal may go away after it soaks for a while but it has been over a week and still had the squeal today.

Back to the ANL Fuse question...why are the Blue Sea System fuses so much more expensive than the ones I see on Amazon? Is there something special about them?

Cheers,
Jim

The Blue Sea fuses are real ANL's tested for ignition protection, have trip delay curves and they have a proper AIC rating. I personally tested a huge batch of elcheapo ANL's from Amazon and a fair number of them failed in an unsafe manner. Scary stuff... They also lack the trip delay durations a true ANL is built to handle.. I would not suggest using anything but a Class T, an IP rated ANL or an MRBF fuse for a battery bank..

Maine Sail · Dec 27, 2013

c130king said:
Can that last sentence be interpreted to mean you recommend "a Blue Sea fuse"?

Thanks,
Jim

Yes! They are not made by Blue Sea but Blue Sea has paid for the ignition protection ratings and they are built to BS specs. They are very high quality fuses that are purposely designed to handle motor starting loads..

woodster · Dec 27, 2013

after looking at the fuse to wire gage chart ...i have new #2 wire from guinedezels on a 180 battery bank that powers a 2gm20f yanmar if i read it correctly i need to use a 200 amp fuse...am i reading this chart correctly.....thanks...

regards

woody

Maine Sail · Dec 27, 2013

woodster said:
after looking at the fuse to wire gage chart ...i have new #2 wire from guinedezels on a 180 battery bank that powers a 2gm20f yanmar if i read it correctly i need to use a 200 amp fuse...am i reading this chart correctly.....thanks...

regards

woody

Woody,

Where engine starting is involved I really don't like to see fuses below 200A. The risk of a nuisance trip is too great. If you regularly overload a fuse it develops edge burn and eventually trips in a nuisance manner.

I have posted this before but one needs to keep in mind that the ABYC allows for 150% of this rating for OCP, if it is needed.

I have also posted this before. 300A fuse on 15' of 8GA wire connected to a 400Ah LiFePO4 battery bank capable of throwing 20,000+ amps into a dead short.

woodster · Dec 27, 2013

thanks for the reply Maine...so if i go to 250 amp i should be ok fine.....

regards

woody

Tom J · Dec 27, 2013

c130king said:
The sailing was very nice. Temps in the low 50's with winds around 7-10. Cloudy but we got a sunset when the sun got low enough. And we had a few dolphins checking us out. Mississippi Sound is nice sailing most of the time.

The boat looks great...new polishing and wax job. And is running great except for a few minor issues:

1) the aforementioned ($0.50 word alert) ANL fuse...and...

2) I now have a "squeal" between about 1300 - 1800 RPM. Idle around 1000 and max at 2500. Did not have the squeal before the boat went into the yard a few weeks ago. Suspect the cutlass bearing...but my friend and I aren't 100% positive on that. Prop and shaft are now much cleaner...numerous barnacles before being sand blasted. I had no zincs...one put on in Summer was gone (no trace). Have 2 1" zinc footballs now. And now there is paint on the exposed shaft and prop. Yard manager told us that cutlass bearing could dry out and the squeal may go away after it soaks for a while but it has been over a week and still had the squeal today.

Back to the ANL Fuse question...why are the Blue Sea System fuses so much more expensive than the ones I see on Amazon? Is there something special about them?

Cheers,
Jim

I have a similar squeal in the same RPM range. When I step on the companionway stairs, the noise stops, so it is apparently vibration induced. Hope this helps.

Witzend · Dec 27, 2013

My Gore Tex packing tends to squeal from idle to ~1350RPM, but I run it almost drip less.
Try loosing the packing nut and see if it goes away.