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Fuse size for fuse panel?

10K views 34 replies 9 participants last post by  JiffyLube 
#1 ·
So we are installing a blade fuse panel. I got it in position and along with some other components and then happened to look at the instructions for the blade fuse block. Shouldn't of done that! It says I need a 150 amp fuse max size for the fuse panel. OK I looked at them in the store and there is a lot of different sizes of fuses. Should I just put in the max size or how can I tell what my needs are?


Thanks,
Chip
 
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#2 ·
I would need to read the directions, but maybe what they meant was that the wire supplying the power to the panel should be big enough to handle at least 150 amps and fused between the battery and the panel with a 150 amp fuse?

I count 12 fuse blocks on that panel. If they all had 10 amp circuits that ran at the same time, that's 120 amps. (unlikely that would ever happen, but you need to plan for the worst)
 
#4 · (Edited)
Yep Ray has the answer..Its in case of a major short to disconnect the batteries completely...It will be a separate fuse mounted close to the battry bank.

http://www.defender.com/category.jsp?path=-1|328|296553&id=823925
 
#5 ·
ATO/ATC fuses have a maximum size of 30 amps.

Fuses are to protect the wire, not the item at the end of it. The exception to this might be low draw electronics that use a smaller fuse. If using 14 awg wire which is pretty normal, 15 amps is appropriate. Thar is why all Blue Seas circuit breaker panels come standard with 15 amp breakers. The maximum rating for the fuse block is 100 amps.

I have no idea where you read 150 amps.
 
#6 · (Edited)
Tommay makes a good point. That is not a good place for either the fuse block or the main switch. In an emergency - shorted battery for instance - you need to reach the main switch. It should not be in the immediate vicinity of the batteries. And corrosion from the batteries will not be good for either the switch or the fuse block. Or any bus excepting the maxi bus on the left.

I try to keep all wire connections (other than heavy wire buses) as high as possible, usually around counter height. Exceptions are bilge pumps, settee front lights, and engine wiring where necessary. No small gauge wires run in the bilge except for bilge pump and transducer wiring.

And holding down the batteries?
 
#7 · (Edited)
Sorry to blow your entire new electrical design, but the guys are right. Get those items (fuse block and switch) out of the battery box. Even if vented, it's not a good idea to have those things in there. You could keep the large bus bars, but the smaller items will die in there, very very soon.
 
#8 ·
If there's an electrical fire near the batteries... you really don't want to have to reach over them to shut them off...since you'll give the fire a lot more oxygen...

You really want to strap the batteries down or install a wooden bar to hold them down. You really should put covers on the positive terminals, if not both sets.

It would also make a lot more sense to have the battery cables go to the bus bars in a different area of the boat and have the fuse panel and switch located there. It would make it a lot easier to work on them and not risk accidentally shorting the batteries.

BTW, the ATO/ATC fuses go up to 40 amps, not 30. :D
 
#10 ·
#12 ·
No, they're not common, but I've used them for a few projects. :D
 
#13 · (Edited)
Where oh where will they go

OK those are good points.
I can move the switch and the fuse panel out of there. The big 400 amp fuse and two 400 amp busses and the two 250 amp busses would need to stay. The 150 (small buses round and straight ) could they stay?

I think the large fuse needs to be as close to the positive post of the battery as possible.

The batteries are temporary. They came with the boat and I researched them, they are old. We are in the process of building our refer so there is really nothing running off them but some LED lights and the anchor windlass.

We plan on replacing the batteries. I was hoping for AGM's but is may well be Trojans. At any rate they are secured along the sides with wood. At this time the design is in the works. I am not sure what batteries are going in there so we have not gone further with a tie down hold down on the top. We have been working on the boat for 1 ½ years and have not seriously sailed out of the harbor in San Diego much so there has been no threat to the batteries.

We will be re-powering in a month or so and that is going to consume 2 months of time before the new motor is in. There is a one month time of no motor. So we have time to figure it out with the electrical.

This is good input.

The batteries are under the satee. So they are not in the bilge.

Satee space before battery move


Now - satee still works fine. It is a fold out bed so there is plenty of support.
It is covered so there is no chance of dropping anything in there.


There is limited space and places for six batteries. Plus a starting battery. We will be adding two more house batteries. They will go next to these in the next section of the satee. The starting battery is located by the engine. We did not want the batteries in the bilge or by the engine.
I wish there was a place for all the fuse blocks etc away from the batteries but there simply is not.

We are running 4/0 wires also so that requires space. We have a 2000 charger inverter that is 10' away or more from the batteries so 4/0 is required.
I will try to re-think the placement of the large fuse blocks. There is of course a down side to each move. The anchor windlass wires would need to be re-sized if we add length to them. There is no sense with running them in a long loop so where the end at the battery buss now is good. So I could move the 150 amp busses and the switch and the blade fuse panel out of there to behind the nav station. About 10' to 14 feet away as the wires run around and around. The battery ground needs to go to the 400 amp buss. I can not think of another location. If I go to the next satte compartment there will be two batteries there also. Wish I could get all six in this one spot. I can re-try
on that. It could be if I built a little shelf to enlarge the the way the hull shape confines the space. If could fit two more batteries in this space and put all the buses in the next satte space. Not sure about AGM or Trojans sizes, I will need to look them up.

Nav station




I was wrong, the fuse is actually a 125 amp (max) that goes in the positive wire to the blade fuse panel.
30 amps per circuit
100 amps per block
32 vots DC

Please remember this is all still very much under construction :)
 
#14 ·
The items that should be moved are pictured below. The heavy cable busses can stay. The T class fuse has to stay as well.

As far as strapping the batteries down, plan on being at 90+ degrees and strap them accordingly. If and when you get knocked down the last thing you need is an electrical fire.

Trojan batteries or comparable are a better value than AGM and could well last longer.
 

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#15 ·
The buss shuffle

Got to the boat yesterday and made the changes.

How's this look? Got the two 400 amp busses and the two 250 amp busses in place and removed the rest. Left the big fuse where it was. One 400 amp buss is hard to see because it has a black cover on it. I will get covers for the rest.

Am I ready to do the cable ordering for these busses and fuse connections!!




Also I removed these items like sugested

 
#17 ·
Just curious, but why do you need all those bus bars in the battery compartment. Aside from the batteries, what are you connecting to them and why???

Very little should be directly connected to the batteries.
 
#18 ·
600 amp
engine ground to buss
battery neg to buss
Buss to 250 amp buss
One post for growth?

250 amp buss
600 amp buss connecting
Anchor windlass
To 150 amp buss in nav station
To blade fuse holder in nav station

Also I am just not sure what we might need as we are still building out the boat.
Refer - in the works
Water maker
AC for Mexico?
TV & speakers
We will be adding another shore power 110 line.
Does not sound like it but we are trying to keep it simple.
We will be living on the boat at anchor and marinas for the rest of my life. I am 64 so say 15-20 years.
So I am thinking it does not cost much to put them in and it is easier now than later.

Is this flawed thinking?
 
#19 · (Edited)
What Dog is saying is that all this should be at the rear of your electrical panel not in your battery compartment. (The direct windless connection to a fuse is OK)...but all the other stuff you want ran through breakers or your fuse panel anyway..no?

Some thing like this.
 

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#20 ·
OK so I lose the 250 amp busses and just go with the two 600 amp busses and the big fuse block.
On the negative side
1. Then I run the engine ground neg to the 600 amp buss
2. Then battery negative to the 600 amp buss (can go on same post as engine ground)?
3. Then connect the anchor windlass to the 600 amp buss.
4. Solar controller would connect to it.
5. Battery charger to it.
6. Then run a cable to the nav station (where the electrical panel is) to a negative 150 amp buss.
7. Then run a cable to the nav station (where the electrical panel is) to a negative blade fuse panel buss

Could one buss connect to another or would that possibly overload the buss?

Some cables would need to share a post.

So in the picture I see what I think are three negative busses.
This chart confuse me with the panel.
Can you explain this. For instance "White". I am guessing that color was chosen to represent something that was not on the chart list?
Boat Wiring

Anyway one looks like it has a couple shunts connected to it so that must be battery charger.

There are two busses without cables connected to them. The ones without the shunt. I do not understand how they are providing a ground without as ground to the batteries through a cable, loke a 1/0 cable?

I do not see any positive wires going to a buss.

On the positive side of the 600 amp buss the big fuse would connect to the buss.
1. The battery would connect to the buss also.
2. The solar controller would connect to it.
3. The battery charger would connect to it.
4. The anchor windlass.
5. A selector switch.
6. Then run a cable to the nav station (where the electrical panel is) to a blade fuse panel

Some can share the same post on the buss?

Then a cable to it would run to a blade fuse block at the nav station that would be mounted in back by the breaker panel.

And by the way thanks for taking the time to help me, you guys\gals are great. Are you ready to tell me to go buy a book yet, but I feel I am so close to getting it!
 
#21 · (Edited)
Oh Sorry.... some of this is AC House wiring as well...The positive main DC bus is attached to the under side of the shelf/work bench from lack of space and to keep all hot wire terminals better protected...It has the heave gauge battery cable attached to it that you are looking for...I dont have a picture of this...sorry.

Also the wiring was not 100% completed in this picture.
 
#23 ·
That is an AC source selector switch. Used for shorepower/ generator switching or possibly shorepower/inverter switching. Shown below.

Chip
The 2 shunts are for battery monitors (one is visible in the upper right) and/or ammeters.

Your plan sounds good to me. Yes, multiple connections are allowed on the busses, up to 4 per stud although I try to keep it to less when possible.
What size cable are you running to the fuse blocks?
 

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#24 · (Edited)
Thats a industrial grade flux reactor capacitor drive switch like Brian pointed out...I have no clue what it does but Im anxious to get out there and start pushing buttons and turning knobs...:D:eek: :laugher



Hes right on...its the AC /gen selector or all power off switch..;)


Hows work been in this weather Ray?
 
#25 ·
Hes right on...its the AC /gen selector or all power off switch..
Hows work been in this weather Ray?
I stayed off the water Monday and Tuesday while it was blowing. Sun came out Weds when I was out checking JRD22's neck of the woods.

BTW, after watching your video on refinishing your floor, I went out and bought a decent router bit set at home depot. OMG, nothing like having the right tool for the job. I can make saw dust wood chips much more efficiently now.
 
#26 · (Edited)
LOL...just watch the fingers...them routers only like to go one way safely...;)

Wanta play hookie and help me hang my boom some day soon?

Woops sorry for the drift...um er...lets see..oh ya turn a knob or throw a breaker or something?
 
#27 ·
Chip,

I'll tell you a good place to put batteries in our boats, and it's closer to the centerline...providing your year boat is built like mine.

In the berth area under the two large pull out drawers, there is a long door that opens downward to the floor. We have a large gel (8G8D) located in that space in a hold down box mounted length wise, and there might be room for two of those batteries there...might be a tight fit though. It's a good place for no maintenance batteries, if the batteries are not to high.
 
#32 ·
Which spot will they fit in



Yes ours is built that way. I think that is one thing Islander did not change as the years went by.

That would be a good spot. We will be cruising so we need that storage space for other items. It is about the only place our Honda 2000 genset will fit and the same goes for the Sailrite sewing machine and I can still get my guitar and other items in that space. Mostly I keep the guitar in the salon.
Also like you said it is not accessible to do maintenance.

We would like AGM's and even though they are coming down in price it may be we go with wet cells so maintenance would be an issue.

Why does everything that goes into a boat need to be on the rail or some other place (fore or aft) and that is not distributed well. We would like to have the batteries low and center but we compromised.
Hay yea it also helps balance the boat because it lists to port.

I read a blog once were the person explains that we humans and want everything flat and square. But on a boat that is a hard feat. Most all if not all of nature in not flat or square.

Our batteries were in the hanging locker in the stateroom by the PO. The big hanging locker. That was great weight wise. Low and center of boat. A bear to work with and my wife wanted them out from within her clothes.
There is also space for four batteries under the galley deck but for nothing else, no bus and not the two more batteries we want to have (6) and the space is more aft.

Besides, as the batteries move forward they spread the weight around and get closer to the center of the boat.

So this is what we came up with. We know Raferty uses this space for his six batteries and he has the same charger\inverter. Works well for him and he is in the South Pacific now cruising.

We also wanted the charger\inverter out of the living space for heat and noise reasons.

So that is the reasoning and logic etc.
They sure are easy to service.

Our dock mate has a ketch and made battery spots for 4 wet cell batteries. Two spots were hard to get at so he burnt up two batteries for lack of water. Because they were hard to get at he did not service them.
He is now in the process of putting his batteries under his satee. The spot was previously occupied by a water tank. I saw it open and the baffles still there. He has since removed the baffles and built in a plywood box.

Of course there are batteries in all kinds of places on the Islander Freeport's and they work for their captains.

We just need a bigger boat :)
 
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