Wiring Schematic - Needs Proofing Before Installation

[demonboy]

Hello all, a happy new year to you and also a 'hello again' as it has been a very long time since I last posted.

When I last left you I was looking at installing a Sterling Pro Alt C 80amp charger, the discussion of which you can find on this thread. I got some really useful help and responses. I learnt a lot and am now ready to do the installation.

Before I do, I wanted to get my head around my wiring and I have made a much better effort at my previous attempt at creating a schematic. It's still not complete but the gaps I think are obvious (e.g. alternator wiring). The rest is everything I have pieced together today and would be very grateful if you could take a look and give me your thoughts. The schematic is as everything stands at the moment and my aim is to simplify it. I'm sorry I have no experience at drawing a circuit diagram.

Some considerations:
- I am getting rid of my external alternator regulator for the time being, so the schematic currently shows something that will be lost when I come to do the install.

- The schematic shows the engine isolator switch going to the domestic bar, and no domestic isolator switch at all. This is done to reflect exactly my current wiring and I presume this is because the Turkish electrician who did the last wiring couldn't speak English, though his intentions were correct. I assume i will need to swap these around.

- I'm unsure of the position of the 1-2-All switch in the schematic. I am assuming it is, from the top clockwise, 1, 2, All. When I come to rewire this I will bypass this switch. When this is by-passed I guess i will be using the isolator switches instead. I will also need to wire an emergency bridge between engine and domestic for emergencies. Perhaps I can use the switch for this purpose instead?

- The diode will be omitted in the installation since the Sterling has built-in diodes.

- The sensing wire will be omitted

- There are still a couple of things missing like solar panels to domestic and anchor windlass to engine battery (will be moved to domestic) but I wanted to post this up to get some initial feedback

- Tomorrow I hope to put together the proposed schematic. There is an example of one in the thread I provided a link to by SJF.

 

[demonboy]

OK, got the image up. Have posted it into the OP. Stupid 3G dongle connection in India to blame

 

[VicS]

There are several features of your diagram I do not follow.

I cannot see any problems with SJF's suggestion.

 

[demonboy]

Hi Vic,

I've used SJF's as an example and come up with this. If you have just a moment to glance your expert eye over it I would be very grateful. The only difference is the extra charging wire from the Mastervolt to the starter battery.

I'm thinking I should probably use the old 1-2-All switch as my emergency parallel.

 

[pvb]

Rather than wiring the emergency parallel switch to the engine battery side of the engine isolator, I'd suggest you wire it to the starter motor side of the isolator. In this way, if your engine battery is flat, operating the parallel switch won't let the domestic battery bank discharge into the engine battery.

 

[demonboy]

OK, I understand the logic and think I understand the practical implication. The fault is as much my poor schematic drawing as anything. Thanks, pvb.

One thing: I have re-wired my domestic isolator and the Mastervolt to domestic, bypassing the 1-2-All switch and just using the isolator, which is a start. However when you look at my original schematic you'll see there are two domestic +ve cables coming out the Mastervolt unit. One goes to the dom battery as it's supposed to but the electrician wired in second cable to the diode, which then goes to a bar, which then goes to the 1-2-All switch. It appears to be bypassing the battery bank but I don't see the logic to this at all. In the short-term I have removed this cable from my circuit.

 

[VicS]

The only thing I can see to comment on is the connection of the emergency paralleling switch which pvb has already pointed out.

The Sterling unit I assume is one of the "Alternator to Battery" chargers.

The wiring between the Mastervolt charger and the diode splitter was one of the things that puzzled me about the old system.

 

[demonboy]

Indeed, me too, but I have my head around things now and am fairly confident I can continue, thanks to you both (in this and the previous thread). There is just one more thing though:

In SJF's schematic his 220v mains charger is only charging his domestic bank. My Mastervolt also charges my starter battery. If I wire this directly to the battery and the isolator is switched on so the starter motor is also connected, surely the Mastervolt will then be connected directly to the starter motor. Is this ok? I know in real life it's an either/or scenario. That is, it's isolated until the mains power is disconnected and the engine is required to start the battery, but if someone turns the isolation key and connects the Mastervolt to the starter motor, is this ok?

 

[pampas]

http://www.quotingsolutions.co.uk/fo...rger_Plan2.jpg

In this system his domestic supply is not in the conventional
take off point, normal to come from the battery via isolator s/w rather than be alt fed.

Nice clear drawing, easy to follow and pleasing to the eye

 

[pvb]

http://www.quotingsolutions.co.uk/fo...rger_Plan2.jpg

Might need to correct that link...

 

[demonboy]

Might need to correct that link...

Yes, seems like the link shortner has got a bit ambitious. Please could you repost, Pampas? Ta.

 

[pampas]

http://www.quotingsolutions.co.uk/fo...rger_Plan2.jpg

Copied and pasted from op. but still does not work, being a Dinosor at this perhaps somebody can point me in the right direction. Thanks

 

[BabaYaga]

My advice would be that you consider the fusing of the various leads at this point. How you chose to solve that might influence the wiring to some extent.
If you are going to install main fuses at the batteries you need to think about how that will effect the possibillity to use the domestic battery for emergency engine starting (the fuse rating will likely be different for the two batteries/banks).
If you have main fuses, perhaps the switch between the Sterling and the engine battery is not so vital and could be replaced by the old A-B-both?
You will probably have a fuse block for the "always on" loads. This could also be used for the feeds from the Mastervolt charger and solar.

 

[demonboy]

Pampas, wrap the image link with the [ img] [/ img] tags, without the spaces. E.g.

[ img]http://www.awebsite.com/apicture .jpg[/ img]

... but without the spaces.

 

[demonboy]

If you have main fuses, perhaps the switch between the Sterling and the engine battery is not so vital and could be replaced by the old A-B-both?
You will probably have a fuse block for the "always on" loads. This could also be used for the feeds from the Mastervolt charger and solar.

Hi BabaYaga. I'm not sure I understand your proposal. Could you expand, please?

And could anyone give me some advice on the Mastervolt connecting to the starter motor when switched on? Is this ok?

 

[VicS]

And could anyone give me some advice on the Mastervolt connecting to the starter motor when switched on? Is this ok?

I would want to check this out with the instructions for the charger. It may be Ok but if the charger is not designed with this possibility in mind it may not. I'd expect it to be OK

I assume you have fuses in the output wiring of the charger.

I would try it. If the fuse blows then you will have to give the matter some thought.

If necessary one of three possible solutions:

A manual switch to disable the starting while the battery charger is on

A relay with a mains voltage coil which will disable the starting circuit when the charger is switched on. ( a little uneasy about that as it will involve both the low voltage system and the mains voltage being connected to the same component.... careful choice of relay will be required).

A relay which will disconnect the charging of the starter battery if the ignition is switched on. A heavy duty relay will be required to carry the battery charging current.

 

[pvb]

My Mastervolt also charges my starter battery. If I wire this directly to the battery and the isolator is switched on so the starter motor is also connected, surely the Mastervolt will then be connected directly to the starter motor. Is this ok? I know in real life it's an either/or scenario. That is, it's isolated until the mains power is disconnected and the engine is required to start the battery, but if someone turns the isolation key and connects the Mastervolt to the starter motor, is this ok?

It isn't a problem. There are millions of boats with dual-output chargers wired direct to the domestic and engine batteries. There's no need for complicated switches or relays.