Scott, if you do your own batt cables.... check this out first .... Making your Own Batteries Cables .... it comes from a very questionable source however ...
Fusing Your Batteries - Another Option
- Thread starter Maine Sail
- Start date
Am I missing something?
I bought the type of set-up everyone is describing but it didn't fit under the covers to my battery boxes nicely - the lids were sort of not on all the way, crooked, and strapping the battery box down over the fuse was not an option. Isn't anyone using battery boxes or am I missing something?
I bought the type of set-up everyone is describing but it didn't fit under the covers to my battery boxes nicely - the lids were sort of not on all the way, crooked, and strapping the battery box down over the fuse was not an option. Isn't anyone using battery boxes or am I missing something?
Like always change is constant and I decided not to use the MRBF's. Went with ANL's again for wiring flow...Still like them but just not for this install due to where I needed my wiring to land..
Just finished laying out my battery wiring panel..
Still like them but just not for this install due to where I needed my wiring to land..Just finished laying out my battery wiring panel..
Excellent Layout MS!
It's funny how I was just on the phone with Blue Sea Systems this afternoon before I saw this thread! I have been scratching my head over my own layout and I decided to use those MRBF's for the cables from the batteries to the ACR. I was asking the tech rep about my alternator output wire because as it stands, it is wired to the positive post on the starter. The tech rep said it is a common installation and for a small system like mine (35 amp alternator output) it shouldn't make much difference, so I was not intending to wire my alternator output to the battery terminal as the wiring diagram for the ACR shows. It look like you run the alternator output to a separate fuse block.
I asked him about fuse protection for the start cable and if I'm not mistaken, I was told that it normally isn't done (amps are potentially too high and fuses would blow too often?). If I'm reading this thread right, I should be incorporating a fuse? The starter can be powered by just the start battery, or both batteries, depending on the switch position. I have the Blue Seas combiner switch which has both batts on and separate or combined depending on switch position. So does it make sense to put the fuse in line between the switch and the start post? I wasn't planning on this. Without a fuse, however, there is no fuse protection between the alternator output and the battery (thru the switch).
I also don't have an in-line fuse for the panel feed right now so .... I am planning on getting a SafetyHub fuse block with 40 amp MIDI/AMI fuse for the panel. This fuse block gives me a few extra links for misc. applications so I thought it would be a good component for future add-ons.
I notice you make use of positive and negative buss bars? Is this redundant for a reason? I also have the shunt for the battery monitor, but my wiring diagram shows a cable to the engine ground directly from the system post on the shunt. You seem to be bridging to a negative buss. What are you bridging with and is it necessary? I was just going to get started on fabricating a panel to fit in a compartment under a seat in the salon which has good access to where the batteries are and it is nice to see your layout for comparison!
Blitz, I don't use those battery boxes, they are not much good. I have those frame type connections that are screwed to a base and lock down the battery. The tops are open for access. It is a tight squeeze, between the top of the batteries and my access hatch cover, though.
It's funny how I was just on the phone with Blue Sea Systems this afternoon before I saw this thread! I have been scratching my head over my own layout and I decided to use those MRBF's for the cables from the batteries to the ACR. I was asking the tech rep about my alternator output wire because as it stands, it is wired to the positive post on the starter. The tech rep said it is a common installation and for a small system like mine (35 amp alternator output) it shouldn't make much difference, so I was not intending to wire my alternator output to the battery terminal as the wiring diagram for the ACR shows. It look like you run the alternator output to a separate fuse block.
I asked him about fuse protection for the start cable and if I'm not mistaken, I was told that it normally isn't done (amps are potentially too high and fuses would blow too often?). If I'm reading this thread right, I should be incorporating a fuse? The starter can be powered by just the start battery, or both batteries, depending on the switch position. I have the Blue Seas combiner switch which has both batts on and separate or combined depending on switch position. So does it make sense to put the fuse in line between the switch and the start post? I wasn't planning on this. Without a fuse, however, there is no fuse protection between the alternator output and the battery (thru the switch).
I also don't have an in-line fuse for the panel feed right now so .... I am planning on getting a SafetyHub fuse block with 40 amp MIDI/AMI fuse for the panel. This fuse block gives me a few extra links for misc. applications so I thought it would be a good component for future add-ons.
I notice you make use of positive and negative buss bars? Is this redundant for a reason? I also have the shunt for the battery monitor, but my wiring diagram shows a cable to the engine ground directly from the system post on the shunt. You seem to be bridging to a negative buss. What are you bridging with and is it necessary? I was just going to get started on fabricating a panel to fit in a compartment under a seat in the salon which has good access to where the batteries are and it is nice to see your layout for comparison!
Blitz, I don't use those battery boxes, they are not much good. I have those frame type connections that are screwed to a base and lock down the battery. The tops are open for access. It is a tight squeeze, between the top of the batteries and my access hatch cover, though.
Main Sail you need help
Clearly you are suffering from some sort of engineering disorder. I'm not a doctor but I'd say that one of the 9 openings in your body has bearing on the picture you posted.
I love you man,but you need to go sailing in the worst way. I'm thinking sunfish, something with out a bilge pump.
PLEASE get yourself some help. I'm genuinely concerned about your state of mental health.
Clearly you are suffering from some sort of engineering disorder. I'm not a doctor but I'd say that one of the 9 openings in your body has bearing on the picture you posted.
I love you man,but you need to go sailing in the worst way. I'm thinking sunfish, something with out a bilge pump.
PLEASE get yourself some help. I'm genuinely concerned about your state of mental health.
Scott,
That is a very typical installation the only problem is that either bank 1 or 2 can be the start battery. You don't need to fuse your alt but if the big starter wire has a fault and grounds the jumper between the alt and starter post is likely going to become the fuse.
This is generally true on much bigger motors than sailboat AUX engines. I have never blown a fuse on a sailboat aux engine from starting. This can happen on large diesels with lots of mass and high compression such as a big Cummins, Deer, Cat, Mann etc. but I have never once had an issue with a small diesel aux.
I have measured the inrush starting current on my 44HP four cylinder Westerbeke at a max of about 165 amps but this is only for a split second. Many of the starters on small diesels are under 1Kw rated. The M-25 for example is a .8Kw...
I actually used to own a Cummins 220B in a down east boat and started that on a regular basis off the 6V house bank which had a 300 amp ANL which also never blew from starting loads..
The other option to fusing is to contain the start battery cable in a conduit all the way from the battery to the starter as this too satisfies the ABYC standard. Fusing the start bank is not mandated in E-11 but in order to not do so they want the cable protected by conduit and an on/off switch. You as a boat owner do not have to do any of this. Catalina's idea of a "conduit" left me with a dead short to the motor so I am grateful I was fused.
Not redundant I just have a bunch of hot and grounds to wire and I am not a big fan of stacking multiple lugs on a single post so I use buss bars.
No not necessary but I like the cleanliness of the install. The neg buss goes direct to the engine and all the loads are tied into it on the load side of the shunt. I used a piece of brass as my jumper after sizing it for the load as this is cleaner than another short piece of 1/0 wire.
The three fuses on the far left are also buss bared together, like the shunt, to give me the correct fuse sizes for my alt, battery cable and battery charger. The house batt comes into the top of the middle fuse. The fourth fuse on the left is for my inverter and is not on the battery buss but is powered off the battery switch feed via the hot buss bar.
There are thousands of ways to wire this up I am trying to be as ABYC E-11 compliant on my re-wire as possible but it is tough to do to the letter....
Perhaps you can come visit when they commit me...
I'm with Druid on this. Just because a 1/0 wire is capable of 285A, why would you fuse higher than 150% of what your max load requirements are? In a dead short situation, a 50 Amp fuse is going to pop more certainly than a 250 Amp fuse. What am I missing here?
You should not fuse higher than 150%, that is the max allowable table IV rating, 285 amps for 1/0, + 150% for short circuit protection. Usually the max load is going to be the starter and if you choose to fuse your house or start bank, and you also start off these, like most do who have a 1/2/BOTH/OFF switch, sometimes up to 150% of the table IV capacity may be necessary depending upon the size of your wire.
Going over the 150% of capacity rule would certainly be unwise. I try to keep it at rated capacity and don't generally find the need for the 150% rule on small AUX engines, but, this often requires large wire. My 1/0 wire is fused with a 250 amp fuse which is only 88% of the 285 amp max continuous rating for 1/0 wire. 250 amps starts my motor just fine and has done so hundreds of times, no need to go bigger.
A starter, perhaps a windlass or eve a large inverter. As I mentioned you can always rate your fuse at a lower capacity if you can get away with it mine is only at 88% of wire capacity.
Considering I had a 250 ANL blow on a dead short I feel the standards and sizing tend to work.
If you guys want to debate the standards, and if you feel they are wrong, I would suggest writing to the ABYC as everything I have posted comes from the ABYC which is time tested and generally quite thoroughly vetted, especially when it comes to E-11..