high amperage fuses

[tech_dog]

What is everyone doing for their high current fuses?

I'm trying to figure out what I need to fuse the connection between the main battery and the isolation solenoid, and the connection between my aux battery and winch.

In order to keep all my options open, I need a fuse that pops at 500 amps, as the max winch amperage is 475.

I'm looking at this: http://www.northeastmarineelectronics.com/browseproducts/BLUE-SEA-5003-FUSE-BLOCK-ANL-500-AMP.HTML

Has anyone found anything better or more cost effective?

T.

 

[Mike S]

I noticed that this fuse block "Accepts wire sizes 18-4 AWG from sides or bottom."

How much amperage will your winch draw at maximum load - 475 AMPS? Even #4 AWG is not heavy enough for of 12V/475 AMPS to the winch over a short run. You'll get about 11 volts at the end of a 3 ft run of AWG#4 wire. And the wire would act as a fusible link and get fried. I suggest that 2/0 copper stranded welding cable be used. You prolly already know all this stuff, if so, please ignore me.

I have seen HD fuse blocks at West Marine, and replaceable fuses to work with them, so you might check them.

M

 

[SR.GRINGO]

I purchased a fuse block at West Marine but I think the biggest they come in are 300 amps. They are called mega fuses. Here are couple 400 amp versions that you might consider. The 2nd once excepts 4/0000 wire.

http://www.westmarine.com/webapp/wcs/stores/servlet/product/10001/-1/10001/17899/10001/119/118/9

http://www.westmarine.com/webapp/wc...119&subdeptNum=118&storeNum=9&productId=17898

 

[Hants]

BlueSea offers both ANL and T fuses in this range. The T fuses are "quick".

ANL Fuse Block (325-750A)

<http://www.bluesea.com/product.asp?Product_Id=31067&d_Id=7463&l1=7463&l2=>

ANL Fuses (50-750A)

<http://www.bluesea.com/product.asp?Product_Id=23472&d_Id=&l1=&l2=>

Class T Fuse Block (225-400A)

<http://www.bluesea.com/product.asp?Product_Id=31068&d_Id=7463&l1=7463&l2=>

Class T Fuses (225-400A)

<http://www.bluesea.com/product.asp?Product_id=148552>

You might also consider a winch power switch (to completely shutoff power to your winch)

<http://www.bluesea.com/product.asp?Product_Id=174047&d_Id=18013&l1=7459&l2=7492>

or the slightly lower intermittent rated

<http://www.bluesea.com/product.asp?Product_Id=174084&d_Id=18013&l1=7459&l2=7492>

 

[tech_dog]

The block I linked to has a maximum rating of 750 amps, and I was going to fuse it at either 400 amp or 500 amp. I was going to go with the ANL type because it's flash protected and safer around gasoline fumes, i.e. under the hood.

Mike noticed that the wire size seems inconsistent with the fuse block rating. I sent an e-mail to Blue Seas last night asking for clarification, but have not yet gotten an answer. They make what looks like a physically identical 400 amp T class unit that is rated up to 2/0 wire, and I think it likely that the description is inaccurate and that 2/0 wire can be used.

That was really the reason for posting this question. I'm hoping that a "been there, done that" person pops out of the crowd.

 

[tech_dog]

I just got a call back from a very helpful tech support person at Blue Sea, and you can indeed run 0000 (4/0) into the Blue Sea 750 amp ANL fuse block, model 5003. The description on the Blue Sea web page is not accurate.

EDIT: They've now updated their web site with the correct description. That was pretty quick....

 

[Mike S]

That makes sense. No way to run that amperage thorugh such a small pipe. Please post on how this comes out. I am going to do a dual batt in the 80 - loved it in the 60.

M

 

[John E Davies]

I've never fused a super-high amperage cable, so I can't help specifically.

But remember that you can very easily parallel two smaller fuses and get double the individual rated current through them. As long as both sets of connections are kept clean and protected with silicone grease or an anti-corrosion spray, the currents should stay equal through the two legs. The best setup would be two fuse blocks side by side connected by heavy copper bus strips.

"Mega" electrical components tend to get exponentially expensive as the rating goes up, and the physical size grows also. Two smaller, cheaper fuses for each circuit might make more sense.

Me? I am going hydraulic

John Davies
Spokane WA

 

[tech_dog]

I thought about going hydraulic, but I decided that the increased risk of a power stearing system failure more than offset any potential benifit. I also discovered that the Milemarker winches only give about 75% of the rated load on an 80 because of the 80's low PS pump pressure.

I've got the fuses mentioned above on order, and will post some pix if it goes well and I don't start any fires.

 

[Mickldo]

Don't have fuses on my 80s dual batteries or winch setup, I don't think they are 100% necessary but at work when I wire up dual batteries for the Ergon Electricity Land Cruisers and trucks I use circuit breakers. The circuit breakers are rated at 150A and when I need a higher rating I wire them together in parallel using buss bars. Depending on the application I wil use either auto or manual reset circuit breakers.
I prefer the circuit breakers to a fuse as a circuit breaker can be reset easily in the field after it has cooled down or the fault has been fixed whereas a fuse needs to be replaced, if you have one.

 

[Hants]

The circuit breakers are rated at 150A and when I need a higher rating I wire them together in parallel using buss bars. Depending on the application I wil use either auto or manual reset circuit breakers.

Do you bar the switches also (so that if one blows it physically turns off the others)?

What would cause you choose manual versus auto reset breakers?

 

[tech_dog]

I would have rather gone with breakers, but with a peak load of 475 amps I couldn't find anything that would result in a clean installation. I'd have needed 3-4 breakers to meet the load, and I'd need a very good distribution bus in order to load them equally. Otherwise, the "shortest path" breaker woudl flip first, and the rest would cascade.

I thought about skipping the fuses in order to keep things simple, but I really don't want to be surprised by an arc welder under my hood.

 

[Mickldo]

Do you bar the switches also (so that if one blows it physically turns off the others)?

What would cause you choose manual versus auto reset breakers?

I only use the auto reset breakers when bussing them together. I'll only use the manual reset circuit breakers if specifically asked for in the quote.
I'm only a dumb mechanic not an auto electrician so if I'm doing this wrong or somebody can show me a better way I'm all ears.

tech_dog, I skipped installing fuses or breakers on my dual battery/winch installation as I didn't think it was necessary. Starter leads aren't fused. Just make sure whether you fuse it or not to add extra insulation around the cabling anywhere there is a possibility of rub through. Make sure to secure the cabling using zip ties or similar to stop unwanted movement too.

Mickldo

 

[alia176]

I've have never fused any of my winch leads either. I've measure with a amp clamp on rare occasions the winch to draw over 500 amp when the stuck vehicle was getting pulled out of a deep mud hole. I can't imagne having to fuse this cable!

Ali