Aaargh. Solar wiring confusion...

[chenderson1965]

Hi.

The good news is that my new panel, and old panel with changed controller, are both now working perfectly. I can see on the phone app that they are connected, charging and moving through the bulk/absorbtion/float stages as I'd expect. The batteries are also clearly charging from the readings on the vehicle control panel (N&B Arto 2012).

What isn't working as it should is that the battery monitor on teh main control panel is not showing the correct current flow. When everything is switched off, it usually shows a small outflow of about 0.5-0.7A from the leisure batteries, which I guess is the control panel and a few other bits of small drain. However, this current doesn't change - even when the panels are both in full Sun and I can see they are supplying lots of current to the battery. When I add a big load (running the fridge on 12V), the regulators do as I'd expect and ramp up their current delivery but, again, the full draw from the fridge (15-16A) shows - so isn't reflecting the contribution of the solar.

Jon Good, who has an almost identical vehicle, says that the reading on his control panel does reflect the current from the Solar (i.e. less apparent current draw from loads, and turning positive/net current into battery when sun is strong and everything is off).

My guess is that this is because of where the solar is connected in - which is different to where the control panel measures the current flow.

I have two 80Ah leisure batteries connected correctly - i.e. the main load goes into the +ve on one and comes out of the -ve on the other. However, the solar outputs both connect to the +ve and -ve of the same battery (the one it came with was fitted this way - I guess because access is easier - and I followed suit with the new one).

So, my questions are these:-

1) If I move the -ve from both solar controllers onto the -ve of the second battery, will this make the control panel correctly reflect the net current draw - i.e. including the current delivery from the panels?

2) Is there an even cleverer way of wiring it, using the load output of both solar controllers (they are both Victron 75/15) AND the battery output. I'm wondering if that would mean that the battery would still get solar charging but also the 12V leisure system runs directly off solar when there is sun (only reverting to battery support when the solar current is insufficient). Is that possible?

I hope that makes sense!

Thanks a lot.

Chris

 

[Raul]

Both, consumption loads and charging has to be after the meter so it can read them, it looks like the solar charging is directly to the battery, bypassing the meter, hence no reading. Loads go through meter and registered.

 

[chenderson1965]

Both, consumption loads and charging has to be after the meter so it can read them, it looks like the solar charging is directly to the battery, bypassing the meter, hence no reading. Loads go through meter and registered.

Thanks. Any idea what the meter will look like?

 

[SandraL]

What make and model is the main panel and fuse unit. Eg schaudt or cbe.
Might help with others providing detail.

 

[andy63]

Hi ive read and tried to follow..
It appears your monitor only shows the load on your 12v system.. Regardless of where the power is coming from as borne out by your observations of running the fridge..
So switching the solar connections won't help there ...but I'd do that anyway.. That's the way they should be connected and not just to a single battery.. That way loads and charging of both batteries will be balanced properly..
And your second point of using the load terminals on the controller won't solve it either..
You really need to find out where the present monitor is connected into the system... And assuming its got a shunt that enables current measurement then all connections to load and charging sources need to be made to one side of that shunt in order to see the net current flow into or flow out of the batteries..
Andy..

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[chenderson1965]

What make and model is the main panel and fuse unit. Eg schaudt or cbe.
Might help with others providing detail.

Thanks. Looks like an N&B branded CBE. Pics attached of everything in there except the two solar controllers..

 

[dunnah01]

You'll need to connect the +ve from the solar controller 12v output to the Eingang 12v post inside the CBE panel, unless you have a separate CBE amperometer box.

 

[chenderson1965]

You'll need to connect the +ve from the solar controller 12v output to the Eingang 12v post inside the CBE panel, unless you have a separate CBE amperometer box.

Thanks. I think I can see the Eingang post. How sure are you before I have a go?
The only other thing I can see in there is in the picture below. Could that be the meter

?

 

[dunnah01]

I'm never 100% sure of anything electrical, do you have the wiring diagram in your handbook? CBE panels vary quite a lot, mine has the separate meter which is a white box next to the main panel

The black plugs in your photo look like inline fuses, probably for the solar panels so may be a convenient supply to the Eingang 12v post

 

[chenderson1965]

Thanks. Definitely no separate box like that and, yes, I just checked and that is a fuse holder.

I've just had a look inside teh CBE unit and I can see four large terminals (threaded posts with a nut on each and several connections to each) inside the bottom of it.

It's very hard to photograph with all the wires.

The one on the left is marked -ve (no other label that I can see)
The two in the middle are both marked +ve and there's a label B2 between them (not clear which it refers to)
The one on the right is marked +ve and B1 is written to the right of it - so must refer to that post.

Presumably -ve from solar controllers go to the left post. Is that right?
Any idea which of the +ve terminals I attach the solar controllers +ve to?

Thanks so much for your help.

Chris

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[dunnah01]

The B2 +ve is where you need to connect the solar 12v output wires but without a wiring diagram I can't advise which of the two B2 posts it should be. You're very unlikely to do any damage if you try each of them but if you can trace the wires from each then the one that doesn't go directly to the leisure batteries is the one you need to connect to (normally called exit 12v or similar)

 

[chenderson1965]

The B2 +ve is where you need to connect the solar 12v output wires but without a wiring diagram I can't advise which of the two B2 posts it should be. You're very unlikely to do any damage if you try each of them but if you can trace the wires from each then the one that doesn't go directly to the leisure batteries is the one you need to connect to (normally called exit 12v or similar)

OK. Thanks. And, for clarity, do I also connect the -ve from the solar controllers to the -ve (left hand) post?

Cheers. Chris

 

[dunnah01]

OK. Thanks. And, for clarity, do I also connect the -ve from the solar controllers to the -ve (left hand) post?

Cheers. Chris

No need to touch the -ve wires as this is grounded to the vehicle and battery already, so just red +ve wires to adjust

 

[chenderson1965]

Great. Thanks so much. I’ll need to get some more cable but have found what looks like the correct post so shouldn’t be too tricky.

chris

 

[autorouter]

On a different CBE box, the DS-520, there are four large terminals just like you describe. They are labelled -B2, +B2, +OUT12V, +B1.

Three of them are the same as yours. The -B2 and +B2 go the the leisure battery negative and positive. The +B1 goes to the Starter battery positive.

However the other terminal (third from the left) is meant to be a connection to the battery for charger or solar regulator. I think it's likely that charging current will go through the built-in ammeter shunt, and will therefore be registered by the meter as you require. It's only a guess, because I can't see if there's a shunt at that point, I only have a line diagram that doesn't show one.

The manual I got from post #15 of this (old) thread:

Help with CBE panel

I am looking to find a ignition + on a CBE DS450ra panel I have looked at a diagram of this and was thinking of trying to splice in some where to get a feed for a relay to isolate the hab batteries whilst the engine is running. The reason for doing this I have fitted a B2B a friend at Newark...

www.motorhomefun.co.uk

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[dunnah01]

On a different CBE box, the DS-520, there are four large terminals just like you describe. They are labelled -B2, +B2, +OUT12V, +B1.

Three of them are the same as yours. The -B2 and +B2 go the the leisure battery negative and positive. The +B1 goes to the Starter battery positive.

However the other terminal (third from the left) is meant to be a connection to the battery for charger or solar regulator. I think it's likely that charging current will go through the built-in ammeter shunt, and will therefore be registered by the meter as you require. It's only a guess, because I can't see if there's a shunt at that point, I only have a line diagram that doesn't show one.

The manual I got from post #15 of this (old) thread:

Help with CBE panel

I am looking to find a ignition + on a CBE DS450ra panel I have looked at a diagram of this and was thinking of trying to splice in some where to get a feed for a relay to isolate the hab batteries whilst the engine is running. The reason for doing this I have fitted a B2B a friend at Newark...

www.motorhomefun.co.uk

That's exactly what's happening so OP just needs to make sure it's the +OUT12V terminal that the +12v solar output wire us connected to.

 

[chenderson1965]

Thanks so much for all your help. I took my courage in my hands and switched the connections as suggested - and hey presto! Everything now works perfectly, including the current indicator on the main control panel.

Cheers.

Chris

 

[Ian Bosman]

Yep, you got a bog standard but branded CBE, the distribution box below the fuses is where all the wring goes. Do not try fiddling with the control panel, it all works off the distribution box Marcle Leisure can let you have a wiring diagram but if N&B being German? are anything like EuraMobil also Germanthey will answer all your questions, in English. I even got a full wiring diagram for the motorhome without asking. Never let me down in any of my half a dozen questions over two years.