12V Battery Fuse / Switch install.

[SiteSurfer]

I'm curious about the 'always on' equipment. Is that something I should be aware of.. ie: when I turn my electrics off (now) the whole boat is dead (aside from an isolated solar charging system), perhaps I am wrongly believing that I dont need a bilge pump running in the background?

 

[pvb]

Hi pvb could you point to me to the original thread /drawing

Michael

Certainly...

 

[mjf107]

Certainly...

Thanks pvb

elegant in its simplicity

Michael

 

[SiteSurfer]

I'm doing this. Thanks.

To clarify, is the 100A 250A the wire rating or fuse rating?

 

[pvb]

I'm doing this. Thanks.

To clarify, is the 100A 250A the wire rating or fuse rating?

Fuse rating - these are notional indicative figures, though, the rating might vary according to the boat's individual needs.

 

[Len Ingalls]

Ah, now I see it. Your diagram is based on one I posted here. Like prv, I disapprove of by-passing the isolator switch for the windlass feed.

Ah pvb-it was you I robbed diagram from.
I copied exactly as you posted it & only made a couple of additions. Those were the addition of an ammeter shunt in the alternator output(my own preference but not essential) and a "Block" for always on loads,such as auto bilge pump & fume alarm(again my preference).
I wondered about the windlass take off & concluded it may have been because your dist. panel wouldn't handle that load &/or ,since the connection is shown on the "lower" side of house ammeter shunt,you wanted to see current draw of winch for some reason. I really didn't pay much attention to be honest,& you are correct that a short in winch cable would have to blow the 250A House Bat. fuse,or burn up. Not good. I will revise the diagram to eliminate the winch altogether,as a winch should be taken off the dist. panel IMHO.

Comments appreciated. My boat is wired this way & no problems YET. Any constructive criticism appreciated.
Not: I don't wish to get into arguments about which Bat.bank the alt. is wired to, or the use of 1,2,all,off vs on/off swxs,etc. Those are personal choice things & the ckt will work with either. Just trying to get as simple a diagram as possible that will do the job for the avg. "electrically challenged" do it/repair it yourself boater.
Cheers/ Len

 

[Len Ingalls]

I'm curious about the 'always on' equipment. Is that something I should be aware of.. ie: when I turn my electrics off (now) the whole boat is dead (aside from an isolated solar charging system), perhaps I am wrongly believing that I dont need a bilge pump running in the background?

My boat has a small 450GPH automatic bilge pump deep in the keel & another 2500GPH Auto with alarm up higher. I prefer to keep my bilge as dry as possible & usually it is.
I can leave both pumps on at all times with negligible current draw as they are rarely reqd.
I have propane aboard with safety solenoid,propane locker & good copper lines-as safe as I can make it. In addition,I have a propane/gas fume alert & a CO alarm. I prefer to have them run continuously -very little battery drain for peace of mind.
These are personal choices.
Cheers/Len

 

[Len Ingalls]

Thanks pvb

elegant in its simplicity

Michael

Yes-it is. Thanks pvb

 

[Len Ingalls]

That shouldn't be the case if the right link is selected.

https://www.dropbox.com/s/sp3f69vaatqlidw/COLREGS Decision Chart_V2.pdf?dl=0

On my account but should be accessible to anyone.

Excellent link! May I borrow it? / Len

Richard

 

[RichardS]

No problem Len. The pdf is in my Dropbox but was actually drawn by another forumite.

Richard

 

[Len Ingalls]

Would anyone have any objection to showing the box "Mains Charger" as "Mains/ Solar/Wind/Other Charger" ? or similar. / Len

 

[VicS]

Would anyone have any objection to showing the box "Mains Charger" as "Mains/ Solar/Wind/Other Charger" ? or similar. / Len

Alternative positions of chargers might also be shown. Solar / wind chargers or even the mains powered charger might be connected to the house battery esp if a bi-directional VSR is fitted.

 

[gandy]

Certainly...

How would that work if the engine battery was faulty? I can't see an easy way to take it out of circuit.

 

[mjf107]

How would that work if the engine battery was faulty? I can't see an easy way to take it out of circuit.

I dont see a problem with the original circuit. Turn off the engine battery isolator, close "emergency start from house", when ALT starts to charge the VSR closes charging the house battery bank. If your concerned about the alternative charging position tha VicS suggest you would need a VSR that senses on both sides. Personally I would connect ALT and mains charger to the house bank, also fuse the charger connection close to the battery

Michael

 

[gandy]

I dont see a problem with the original circuit. Turn off the engine battery isolator, close "emergency start from house", when ALT starts to charge the VSR closes charging the house battery bank. If your concerned about the alternative charging position tha VicS suggest you would need a VSR that senses on both sides. Personally I would connect ALT and mains charger to the house bank, also fuse the charger connection close to the battery

Michael

In the diagram, opening the engine battery switch still leaves the alternator hard-wired to the engine battery. If that battery's manually disconnected, to isolate a faulty battery, would the VSR still behave properly with only the alternator (and no battery) connected?

 

[mjf107]

In the diagram, opening the engine battery switch still leaves the alternator hard-wired to the engine battery. If that battery's manually disconnected, to isolate a faulty battery, would the VSR still behave properly with only the alternator (and no battery) connected?

To be honest I don't Know for sure, I thought it would be OK, might depend on the make of VSR. But its a good question

Michael

 

[Len Ingalls]

Alternative positions of chargers might also be shown. Solar / wind chargers or even the mains powered charger might be connected to the house battery esp if a bi-directional VSR is fitted.

VicS Why would you need a bidirectional VSR? If all charge sources are connected to Start bat.,wouldn't the VSR bridge the House Bat. as soon as Start Bat. reached 13.6V ,thereby sharing/shunting the charge to House Bat? Am I missing something?
Cheers/Len

 

[gandy]

To be honest I don't Know for sure, I thought it would be OK, might depend on the make of VSR. But its a good question

Michael

Actually having another look, I think I'd do it like this. Take the alternator to the switch, not to the battery, but on the battery side of the switch. Then the scenario for a failed battery, as opposed to a flat one, is to disconnect engine battery lead, then close all three switches. Everything's then connected to the house battery.

 

[Len Ingalls]

Tony & Michael. I responded to VicS #32 before reading your posts re bad Start bat.

Now you are getting into defective components. I know s..t happens,& it's a good exercise to analyze these possibilities.

A one way VSR probably wouldn't bridge the Start & House bats. since the cut-in voltage sensed at the Start bat. may never reach 13.6V.

Removing/disconnecting/corroded conn. the Start bat. would leave the alternator open ckt. & possibly destroy it's diodes.

I'm not familiar with bi-directional VSRS. I have to assume they sense both House & Start bats & bridge whenever one or the other bat. reaches 13.6V? This would mean a charging source is connected directly to both bat. banks?

Comments?

 

[Len Ingalls]

Actually having another look, I think I'd do it like this. Take the alternator to the switch, not to the battery, but on the battery side of the switch. Then the scenario for a failed battery, as opposed to a flat one, is to disconnect engine battery lead, then close all three switches. Everything's then connected to the house battery.

Tony I agree! I hate connecting anything other than bat.cables to a battery-small leads corrode too easily.
I always make my load& input conns. @ Bat swx if possible. This also allows easier bat. removal,term. cleaning,etc
/Len