question

goodkind avatar image
goodkind asked

Wiring Diagram Feedback

Hi all,

I have been trying to design a system setup for my vehicle that includes multiple power sources. Having looked at a number of other peoples posts I have tried to put together a diagram to show what I wanted to do and wanted some advice on where I may have gone wrong. This area is new to me so please bare that in mind.

Draft 1:

wiring-diagram-draft-1.jpg


Draft 2:

wiring-diagram-draft-2.jpg

Multiplus-IIMPPT Controllerswiring diagram
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1 Answer
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @Goodkind

The BMV wiring is not correct.

Most of your significant loads are connected to Leisure battery, but the BMV is shown wired to the starter battery.

Also the BMV712 model has an additional 2nd voltage sensor, and I would recommend it over the 700 when there are two batteries in a system.

Also you have drawn some fuses/circuit protection, but not others - this might just be on your diagram for neatness, but it is essential to have ALL positive conductors fused.

Good work though, keep going.

3 comments
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goodkind avatar image goodkind commented ·
Hi Guy,


Thank you for your feedback.

I will look into the BMV712. At first glance I wonder if I am going to have to run the leisure battery negative cable direct to the shunt or can it go via the canopy busbar ? If it has to go direct, that is fine, I will just rearrange the design.

As for fusing, I was not leaving some out for neatness, so its apparent I have missed some. Could you advise as to which ones I am missing? (Winch??)

Many thanks

James

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Guy Stewart (Victron Community Manager) avatar image Guy Stewart (Victron Community Manager) ♦♦ goodkind commented ·
The Starter battery is excluded from the shunt measurements - it's not usually necessary to count anyway - as it's predominantly running loads from the alternator, and quickly charged from the brief discharge starting.


The BMV shunt is required to be the first and only thing connected to the target (leisure) battery negative terminal. All other negative connections are then made on the other side of it.

In your case your leisure battery side negative bus bar, you can remove the voltage meter (or move it to the starter battery side) as the BMV will now do that job.

The winch was the main unfused connection that caught my eye - they can be harder to fuse being a heavy load. But there are also wires that are shown to be fused, but then the wire size is not specified.

The fuse/wire size relationship is integral, so can't just specify one without the other. The change in line weight for the 5A leisure loads compared to the 20A indicates you aren't going to (and shouldn't) use 6 mm.

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goodkind avatar image goodkind Guy Stewart (Victron Community Manager) ♦♦ commented ·
Thank you again for the advice on this.

I have updated the diagram with the following:

1. I have swapped the BMV and voltage meter around.

2. I have tried to provide distances/wire sizes for each wire.

3. Have decided to partially ignore the winch for now.

Any more advice will be gladly received.

Thank you


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