Put Blue Sea ANF fuse holder under battery box lid?

Discussion in 'OnBoard Electronics & Controls' started by sdowney717, Aug 2, 2021.

  1. sdowney717
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    sdowney717 Senior Member

    I found it does fit under the lid. Anyone do such a thing?
    I could run a piece of copper bar from lug to lug or just short length of wire, except the copper bar is easier.
    Tell me why it's wrong, bad, boat will explode, daft idea only a fool would consider, etc.... that battery shown is the start battery, all it does is crank engines, nothing else.

    The box is also length wise big enough, fuse could be put sideways on a piece of wood next to the battery still keeping fuse holder inside the box. Slide battery all the way to one end of box. Gotta put wood in the box anyway to keep battery from sliding around
    Fuse holder has side cover breakout tabs
    upload_2021-8-2_18-14-29.png

    I plan to test the 300 amp fuse for the starters and wonder if it will explode. Nah, its all Blue Sea Tech.

    starter bank fusing
    I quote Nigel Calder here:

    "The net result is that nowadays, electrical shorts are probably the number-one cause of fires on boats. There is simply no excuse for not protecting all high-current circuits, including the cranking circuit." (From the Nigel Calder Cruising Handbook)

    Battery Bank Fusing Photo Gallery by Compass Marine How To at pbase.com

    Lets say it nuisance blows someday. I can move house bank rotary switch to 'both, 1+2', and the house bank is joined with the starter bank. Engines will then start. And I am out the $14 spent on the 300 amp fuse. Position #2 on house rotary switch runs a wire to the start battery bus. Normal running that switch stays on 1, off is off, he's dead Jim.
     
    Last edited: Aug 2, 2021
  2. sdowney717
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    sdowney717 Senior Member

    When I post pictures, can you all see them? There is a picture in my first post. Some people say google tells them its private.
     
  3. kapnD
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    kapnD Senior Member

    A 300 A fuse is going to get very hot before it blows.
    Are you sure you want that in your battery box?
     
  4. sdowney717
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    sdowney717 Senior Member

    A 300 amp terminal fuse from Blue sea is also fit in a battery box all the time directly on the battery post. Good question though, do these fuses get very hot in operation. I could see that happening with a poor connection to corroded or loose lugs. These fuses are designed to work in hot engine bays, and are ignition protected, I don't think this is an issue.
     
  5. kapnD
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    kapnD Senior Member

    I’m not an engineer, and do not know the applicable rules, but as someone who does things from a practical point of view, I see that as an opportunity for explosive gasses and high heat to coincide.
    Is space so limited on your vessel?
     
  6. sdowney717
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    sdowney717 Senior Member

    37 foot long 1970 cabin cruiser
    Gasses I know but ignition protected, they put such fuses in a battery box today
     
  7. sdowney717
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    sdowney717 Senior Member

  8. fallguy
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    fallguy Senior Member

    The anl fuse holder is designed to be mounted to something. See the screw holes in it? The reason for the battery cover is to keep out the weather. Is the battery outside in a 37 foot boat?
     
  9. sdowney717
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    sdowney717 Senior Member

    The battery is right next to the engines and can never get rained on, under the main salon floor, under carpeted hatches.
    The battery box is maybe 3 inches longer than the group 29 start battery, so has to be slid back and a piece of treated wood stuck there to keep it from moving around. Plan is to mount the ANL holder to that block of wood. And run a solid copper bar from terminal post adapter straight over to the fuse holder , the wires will align perfectly with the wire formed pockets on the lid of the box.

    And if for some reason, the fuse blows on the starter circuit, I plan to do something similar for the house bank, so the fuse holder will be put to use. Right now, there is no main battery fuses on starter wires, house has 3 large MEGA AMG branch fuses on the house bank, 500 amp semiconductor fuse for the 3000 watt inverter, 150 amp for house, 100 amps for lectrasan head.
    Both engine alternators are fused to 80 Amps (short protection only, alternators cant put out that much) . Victron charger output joined to Alternator output on a buss, with the alt-charger fuse there too in the cabinet then sheathed wires runs to the battery rotary number 1 switch lugs for each bank to which is also the large battery wire to the battery post.

    So over the decades, I have made some improvements to the system.

    Keeping the box lid cover on the batteries also keeps the strap holdown running neatly over the top of the battery box, It came with the box, so plan to use it. Otherwise the strap to hold boatteries in runs across the top of the batteries and wires, and just wont be as good IMO.

    A 500 amp semiconductor fuse will blow instantantly on a 500 amp short, but a 500 amp ANL fuse will take a long long time or never. It takes a lot more amps to blow ANL fuses. Semiconductor fuse has the same form factor as Class T, I used it as it cost less money, I found it on an Ebay sale

    Here is the starter battery box
    Amazon.com : attwood 9084-1 Large 29/31 Series Vented Marine Boat Battery Box with Mounting Kit and Strap, Black, Black, One Size (9084-1) : Sports & Outdoors

    Here is the golf cart battery box, you put 2 batteries in one box, but still have not gotten it yet.
    Amazon.com: Camco Heavy Duty Double Battery Box with Straps and Hardware - Group GC2 | Safely Stores RV, Automotive, and Marine Batteries |Durable Anti-Corrosion Material | Measures 21.5" x 7.4" x 11.2" - (55374): Automotive

    For now, the batteries still sit in their battery tray, as they have done for many years.
     
    Last edited: Aug 6, 2021
  10. sdowney717
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    sdowney717 Senior Member

    I dont think it's worth replying anymore until I actually finish the project and can show some pictures of how it works, videos of it starting on the fuse etc..., if people are just going to not understand or take the time to think about the things I am talking about doing. It is like talking to a wall, waste of time. I still dont have my other box, cant finish the job yet.

    Also I think long descriptive paragraphs are not accomplishing much as far as communication of ideas. Short one line comments are better.

    NEC allows fuses in hazardous locations, some people would say in their view hazardous is inside the battery box, and Blue Sea ANL fuses are ignition protected.

    Originally posted by NEC 240.21 (H)
    Overcurrent protection shall be permitted to be installed as close as practicable to the storage battery terminals in an unclassified location. Installation of the overcurrent protection within a hazardous (classified) location shall also be permitted.

    Unclassified simply means the location makes no difference, install the fuse as close to the terminal as you can. Hazardous could mean any potentially dangerous location, tight spaces closed room potentially with explosive fumes such as a bilge space.
     
  11. fallguy
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    fallguy Senior Member

    I don't have room in my battery compartment for a conventional battery box, so I am custom building the box and hold downs. But I class t in the compartment above the batteries. I still don't understand your purpose for fusing the starts.

    I think installing a fuse holder on the battery itself would be considered an error by most surveyors.

    If the spacer block is mounted and not loose, then the fuse holder might go on it, but wires also require being supported in a boat and they can't support themselves. I don't have the relevant rule in front of me, but seem to recall reading it somewhere. Best of luck.
     
  12. sdowney717
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    sdowney717 Senior Member

    Got it done today. Took my battery tray home since I had to modify the shape and the start battery.
    My tray was made to hold batteries no boxes, so boxes cant fit side by side, and my double Camco box is back ordered to who knows when.
    So for now have to work with what I got.

    It is not a sloppy loose fit inside the box the wood spacer I made from a 25 year old treated 2x4 from my kids playset, which the grandkids still use a lot.
    Glued the sections together with PL premium polyurethane adhesive. Plan to paint the wood white.
    The wood can still move a little.
    The fuse is screwed to the wood.
    A 4/0 or so looking wire very short, part of a joiner for 6vdc batteries which I dont need, I cut and put a lug on the end. I measured the width of the copper strands at 0.46" thereabouts. That terminal is coated brass, and was made so it could be flipped over to allow you run the wires one side of terminal or other side.

    So the short wire still has flex.
    The wire runs to the rotary switch above the battery right from the battery as it always has for decades, nothing has really changed. You could run a couple SS screws thru box at top to fully secure the wood in the box if wanted.

    That is a Group 29 battery in an Attwood box. For some reason they make the box a lot longer. The spacer wood is 2.5" deep, 7" wide at bottom, 8" tall, 7.5" wide at top.
    20210825_145238.jpg
    20210825_145318.jpg 20210825_145247.jpg
     
  13. gonzo
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    gonzo Senior Member

  14. sdowney717
    Joined: Nov 2010
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    sdowney717 Senior Member

    Blue Sea ANL are Ignition protected fuses. They cant explode.
    Though I dont think it will survive a blow torch!
    ANL Fuses - Blue Sea Systems
    And here is how Blue Sea describes ignition protected
    Do You Have The Ignition Protection You Need on Your Boat? - Blue Sea Systems

    Ignition protected devices are designed in such a way that:

    • they won't ignite a surounding air-fuel mixture if there is an explosion inside them.
    • they can't reach a high enough surface temperature or generate enough spark to ignite an air-fuel mixture.
     

  15. gonzo
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    gonzo Senior Member

    Interesting, some are ignition protected. I just learned something useful.
     
    sdowney717 likes this.
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