ANL fuse holder question for the gurus

[flee27]

I am adding a 50 amp charger to my boat and have a question regarding ANL fuse holders. Blue Seas has 2 styles. A 5005 and a 5503. The difference is the 5503 has separate studs for attaching the wire from the fuse. The 5005 uses the same stud for both. The 5503 is also almost twice as expensive. Is there I reason to use the more expensive 5503 other than not having to loosen the wire attachment stud to change a fuse?

https://www.bluesea.com/products/500...r_-_35_to_300A

https://www.bluesea.com/products/550...r_-_35_to_750A

Thanks Foster

[noelex 77]

For 50A the smaller fuse holder is more than adequate. It also has the advantage that it is physically smaller. This often makes installation easier.

It is more fiddly to replace the fuse in the smaller holder, but this should rarely be necessary.

The larger fuse holder is needed for higher currents, but 50A is a low threshold for an ANL fuse.

The smaller holder is nowhere near it limits with this current and is perfectly acceptable. If you have the space, and the dollars, the larger holder is better, but it is certainly not needed for 50A and is arguably overkill.

[BilgeRat]

That would be in relation to how lazy one would be vs $$$. They both still do the same job.

[Ziggy]

The advantages of 5503 are:
1) Higher max current rating;
2) Ability to replace the fuse more quickly without disconnecting cables;
3) Ability to connect more cables (but would negate #2).


The advantages of 5505 are lower cost and less space required to mount.
The choice depends on your requirements. depends on your requirements

[GordMay]

Originally Posted by noelex 77

... It is more fiddly to replace the fuse in the smaller holder, but this should rarely be necessary...

Not necessarily. When stacking the bolts, place the cable lugs on first (bottom), with fuse on top. Thus, the cables can remain in place, when replacing fuse.

[noelex 77]

Originally Posted by GordMay

Not necessarily. When stacking the bolts, place the cable lugs on first (bottom), with fuse on top. Thus, the cables can remain in place, when replacing fuse.

I agree this is the best way.

However, if replacing the fuse on the smaller fuse holder, when tightening down on the nuts the attached cables also want to rotate.

The larger fuse holder eliminates this issue as the cables are retained by a seperate mechanism that is not involved or disturbed as the fuse is replaced. The fuse is easier and quicker to replace.

Given the infrequent replacement of ANL fuses, this is not significant problem. The reason for selecting the larger fuse holder has more to do with larger current carrying capacity of the larger model, rather than the ease of replacement of the fuse. Nevertheless the larger fuse holder is better (ignoring cost) if there room for the installation.

It should also be noted that in some installations (such as lithium batteries) the higher IC capacity of T class fuses is needed.

[Manateeman]

Well I’m glad you asked because I had a long talk with Blue Sea Systems recently. Bit of a story, but hang in there.
I’m doing my DC distribution system over. I bought a tee class fuse block ...the simple, less costly model, #5502. It has the clear plastic cover that you squeeze in the middle vs the more expensive unit with the yellow cover clamps.
Nice looking...but I couldn’t get the cover off.
I squeezed and squeezed. I put a 3inch clamp with silicone finger pads on it.
Nothing. I had to use the clamp and a screwdriver on the back side which will be real fun to do after you unbolt the block.
So I called them. They told me ...yes! It is sometimes difficult to get the cover off. New unit. No sign of any defect in the plastic molding. The two teeth that hold the cover onto the base are a 1/2 inch wide but 1/16 thick so if you file them down, you might end up with a cover that falls off.
This is of course a T block, not an ANL but the mechanism is similar.
The above advice gives you all the advantages of both the less expensive and more expensive units. The issue might have been limited to one holder out of tolerance. I love Blue Sea System stuff. Love it, but I’m going with the yellow latch, four post stuff .
My manatees will just have to limit their drinking which I’m sure will result in them tossing cans of spinach at me.
Popeye ...I guess I’m not. Happy trails to you.
Captain Mark and his spoiled manatee crew

[BAD ORCA]

Originally Posted by Manateeman

Well I’m glad you asked because I had a long talk with Blue Sea Systems recently. Bit of a story, but hang in there.
I’m doing my DC distribution system over. I bought a tee class fuse block ...the simple, less costly model, #5502. It has the clear plastic cover that you squeeze in the middle vs the more expensive unit with the yellow cover clamps.
Nice looking...but I couldn’t get the cover off.
I squeezed and squeezed. I put a 3inch clamp with silicone finger pads on it.
Nothing. I had to use the clamp and a screwdriver on the back side which will be real fun to do after you unbolt the block.
So I called them. They told me ...yes! It is sometimes difficult to get the cover off. New unit. No sign of any defect in the plastic molding. The two teeth that hold the cover onto the base are a 1/2 inch wide but 1/16 thick so if you file them down, you might end up with a cover that falls off.
This is of course a T block, not an ANL but the mechanism is similar.
The above advice gives you all the advantages of both the less expensive and more expensive units. The issue might have been limited to one holder out of tolerance. I love Blue Sea System stuff. Love it, but I’m going with the yellow latch, four post stuff .
My manatees will just have to limit their drinking which I’m sure will result in them tossing cans of spinach at me.
Popeye ...I guess I’m not. Happy trails to you.
Captain Mark and his spoiled manatee crew

no my Blue Seas 5005 ANL cover is just as difficult to get off. i have pretty strong grip and i cant get the cover off without a screwdriver.

[smac999]

take a look at the mrbf fuses. I haven't bothered to install ANL fuses for years. mrbf are so much easier. and can be used on bus bars posts or battery posts.

I wouldn't bother with ANL unless it's over 300a

as for the main difference in your 2 models. one is rated for 300a and one is rated for 750a. that's why it's twice the price.

[smac999]

Originally Posted by GordMay

Not necessarily. When stacking the bolts, place the cable lugs on first (bottom), with fuse on top. Thus, the cables can remain in place, when replacing fuse.

ANL fuses are sloted and slide out. there is no need to remove the cables or the nuts. just loosen nuts and slide out.

[GordMay]

Originally Posted by smac999

ANL fuses are sloted and slide out. there is no need to remove the cables or the nuts. just loosen nuts and slide out.

Good point.

[Jammer]

smac999 is correct on all points:
* The larger fuseholder is suitable for higher currents, over 300 amps.
* ANL fuse replacement is facilitated by slots making it unnecessary to remove the nuts completely even on a two-stud fuseholder.
* ANL fuses are an older style that is largely obsolete

If you're using ANL fuses because you have other ~60A ANL fuses on your boat and are trying to minimize the number of spares you need to carry, great, go for it.

Otherwise you may want to consider:
* MRBF fuses, which are more compact. Del City has Bussman branded fuses which are much cheaper than the otherwise identical Blue Sea Systems fuses. The interrupting rating is 5000 amps at 32 volts, essentially the same as the ANL rating of 6000 amps at 32 volts.
* MAXI fuses, available in ratings up to 80 amps. These have a lower interrupting rating of 1000 amps
* Class T fuses, which have a higher interrupting rating (20,000 amps at 160 volts) but are expensive

I used MRBF fuses when rewiring my boat.

In general the higher interrupting rating isn't necessary unless you have a high performance battery and cabling system that is capable of delivering really large currents. At 12v the voltage drop in the battery cables is enough to limit the current in most cases. 6 feet of #6 cable (or 12 feet of 1/0) will limit you to 5000 amps at 12 volts on a dead short, by the numbers, in practice you would get less than that.

On the other hand for someone running 750 MCM cable from a 24 volt string of L16s, the class T fuses would be a wise investment.

[noelex 77]

There are a multitude of fuse options. It pays to standardise the boat as much as possible.

I think ANL fuses are a great option as they are readily available, easy to change, available in a large range of amperages and not too expensive. Just watch the IC rating.

A system that covers lower amperages is also needed. Here ATO-ATC fuses are often used, but for not much more cost the DIN rail MCB circuit breakers are a great alternative. They are available in a wider range of amperages so cover from small to moderately high currents. This provides an overlap that comfortably covers the ANL option. There is a multitude of industrial connecting and mounting options. The IC rating is much higher than ATO-ATC fuses. This provides added protection.

A great bonus is they can function as switches or provide circuit isolation. It is of course easy to tell if they trip and they easily reset without hunting for spares.

Overall there are many well thought out, flexible, safe and relatively inexpensive industrial switching and circuit protection equipment that is often much better than the “marine” alternative.

[GordMay]

I prefer the ATC* illuminated blade fuses (blown fuse indicator) and holders use Light Emitting Diode (LED) technology, to show that a fuse has opened.

* ATC fused are “closed” to the environment, and are a better choice than the ATO, which are open.