Odd wiring?

[mikefleetwood]

Working my way through refit and upgrade of Musketeer (Moody 29), I noticed something that seems odd in the electrics. There are 2 12V batteries with a 1/2/1+2/off battery isolator switch. I noticed that with the switch in the "off" position that fuse panel is still live. First I though the switch was faulty/damaged, but on looking at the wiring the fuse panel is wired directly to battery 2. The Isolator switch only controls the feed to the starter (and maybe the alternator, but I've not traced that wiring).

So, my question is - is this normal? The only advantage that I can see is that I can always switch on the bilge pump, or any of the domestic circuits. But surely this negates the whole point of having an isolator?

Fortunately, it's a simple relocation of one cable to fix it (if needed).

 

[PaulRainbow]

That's not how Moody would have wired it. It would have been select battery 1 or battery 2 for engine and domestics. A better way today would be a separate switch for domestics and another for the engine, with a third for emergency starting.

 

[mikefleetwood]

Thanks Paul, It will be simple to move the "domestic" supply from the battery 2 stud on the switch to the output stud. It only came to light when I was fitting a Rutland charger and I was checking the connections - switched "off" and surprised to see things still worked!

Incidentally, the Rutland controller doesn't seem to detect battery 2, although I still measure 12V on the terminals of the controller - Is this a common fault? I guess I'll have to talk to the supplier about getting it replaced. EDIT: just found the Rutland handbook (I'd mislaid it!) I connected battery 1 first, so now it doesn't see battery 2 - all I need do is reset the controller and it will do both batteries.

 

[MontyMariner]

1 2 both switches can be wired a couple of ways .
Mine is wired
Common - output from switch (to engine starter / alternator / instruments)
1 - Battery bank 1 supplying power to engine starter and instruments / recieving power from Solar and alternator
2 - Battery bank 2 supplying power to engine starter and instruments / recieving power from Solar and alternator
Off - power isolated from engine starter and instruments

PS Solar input to batteries is from a dual output regulator so batteries receive charge irrespective of switch position. The 1 and 2 switch terminals were a conviniate place to attach the wires.

 

[LittleSister]

Working my way through refit and upgrade of Musketeer (Moody 29), I noticed something that seems odd in the electrics. . .

That's not how Moody would have wired it . . .

I think it's obligatory for second-hand boats to have mysterious amendments and additions to the original wiring.

 

[[70521]]

When I bought my current boat I looked at the rats nest of wiring behind the switch panel and promptly replaced it.

Looking at the battery end was even more of a mess.

I called the previous owner to ask how it worked and they admitted that they did not know, but it worked.

I slowly worked my way through the system upgrading and simplified it.

There are some real bodgers about.

 

[chriss999]

Working my way through refit and upgrade of Musketeer (Moody 29), I noticed something that seems odd in the electrics. There are 2 12V batteries with a 1/2/1+2/off battery isolator switch. I noticed that with the switch in the "off" position that fuse panel is still live. First I though the switch was faulty/damaged, but on looking at the wiring the fuse panel is wired directly to battery 2. The Isolator switch only controls the feed to the starter (and maybe the alternator, but I've not traced that wiring).

So, my question is - is this normal? The only advantage that I can see is that I can always switch on the bilge pump, or any of the domestic circuits. But surely this negates the whole point of having an isolator?

Fortunately, it's a simple relocation of one cable to fix it (if needed).

My Sadler had that arrangement when I acquired her. I found it inconvenient because I couldn’t switch off the power from the panel without disconnecting the battery. So I’ve adjusted it as you suggest - makes a lot more sense now.
There’s no automatic bilge pump so I can’t see any benefits to the way it was done.

Maybe it was done for a reason but that reason eludes me.

 

[wonkywinch]

You just reminded me, I need to disconnect Beneteau's "charter fleet battery protector" on my boat. You can't use the anchor windlass unless the engine is running. Since my immediate action if I had an engine fail whilst motoring down a river or near a lee shore would be to drop the hook, I need to be able to do this using my helm remote. Impossible with current (factory) set up.

 

[PaulRainbow]

You just reminded me, I need to disconnect Beneteau's "charter fleet battery protector" on my boat. You can't use the anchor windlass unless the engine is running. Since my immediate action if I had an engine fail whilst motoring down a river or near a lee shore would be to drop the hook, I need to be able to do this using my helm remote. Impossible with current (factory) set up.

Yes, that's a poor way of wiring the windlass, for reasons you state.

 

[mikefleetwood]

Another "postscript"!

I got around to opening the selector switch today - it being a bit damp to do anything that involved going outside! Not only was the fuse panel connected to the "Battery 1" lead, but they were both fitted to the "Feed" terminal, whilst the feed for the starter/alternator was connected to the "battery 1" terminal. I've now rearranged the cables so Battery1 and Battery 2 are connected to the correct terminals and both the starter/alternator and the fuse panel are connected to the "Feed" terminal.

Feels much safer wiring up the new items to the fuse panel knowing the batteries actually are isolated!

 

[howardclark]

After a survey my insurance company insisted that my bilge pumps were always live. I reluctantly wired them around the switch which cost me a good battery when a bilge pump jammed : ( I’ve now linked them to an old battery which I don’t care so much about). Maybe a previous owner had a similar issue and made a quick fix.