Solar Panel Wiring

SimbaDog

SimbaDog

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Need some advice please :). I have a 120W solar panel that will be feeding into one of these regulators http://www.ebay.co.uk/itm/20A-12V-2...ntroller-Regulator-Remote-Meter-/120969949872 this unit has dual outputs for twin battery banks, there are two lots of terminals, + & - . My battery setup is as follows: I have 2 house batteries wired in parallel & a single engine battery, There are 3 battery master switches (simple on & off type), one which is neutral only & one each for positive feeds from the house batteries & from the engine battery.
I need advice on how to wire the supply cables from the solar regulator? Could I for instance run the positive feeds to the live sides of the battery switches & the negative feeds both to the live side of the neutral switch?
Thanks in advance :D
 
SimbaDog said:
Need some advice please :). I have a 120W solar panel that will be feeding into one of these regulators http://www.ebay.co.uk/itm/20A-12V-2...ntroller-Regulator-Remote-Meter-/120969949872 this unit has dual outputs for twin battery banks, there are two lots of terminals, + & - . My battery setup is as follows: I have 2 house batteries wired in parallel & a single engine battery, There are 3 battery master switches (simple on & off type), one which is neutral only & one each for positive feeds from the house batteries & from the engine battery.
I need advice on how to wire the supply cables from the solar regulator? Could I for instance run the positive feeds to the live sides of the battery switches & the negative feeds both to the live side of the neutral switch?
Thanks in advance :D
Click to expand...

I have the 10A version of the same regulator, and that's more or less how I wired it. The regulator has an internal temperature probe, so should be in the compartment with the batteries, though there is an external probe available if that's not possible.

In my case the batteries are wired first to 200A breakers, then to a dual circuit breaker. The controller is wired to the live (ie battery) side of the breakers, because I dislike having wires sprouting from battery terminals.
 
SimbaDog said:
Need some advice please :). Could I for instance run the positive feeds to the live sides of the battery switches & the negative feeds both to the live side of the neutral switch?
Thanks in advance :D
Click to expand...

Yes connections to the battery side of the isolator switches will be perfectly Ok. It avoids JD's dislike of multiple connections to the battery terminals if that is a issue with you too.

Incorporate fuses, as close to the + ve connections as possible, as also advised
 
VicS said:
Yes connections to the battery side of the isolator switches will be perfectly Ok. It avoids JD's dislike of multiple connections to the battery terminals if that is a issue with you too.
Click to expand...

Thanks. The main thing is to have a little resistance as possible between the controller and the batteries, because the controller assumes that what it sees at its terminals is what the battery sees. Losses on the incoming side are wasteful, but significant losses on the charging side can impair the operation of the controller.

The Electrical Aesthete
 
VicS said:
Yes connections to the battery side of the isolator switches will be perfectly Ok. It avoids JD's dislike of multiple connections to the battery terminals if that is a issue with you too.

Incorporate fuses, as close to the + ve connections as possible, as also advised
Click to expand...

Although my controller is not the same one, the rest is pretty similar. That's how my wiring is done, in my case to the battery side of my 1-2-both switch. It has been the same for many years now. The fuses are essential: the boat that burnt to the water in Leros in 2013 did so immediately after the addition of solar panels without fuses.
 
vyv_cox said:
My fuses are similar. I sized them for the panel maximum output, no more.
Click to expand...

Agreed. Definitely a case to forget the "protect the wiring" notion, because if more than maximum output is flowing you could have a broken regulator capable of doing nasty things long before the wires (which ought to be chunk) get anywhere near their capacity.
 
JumbleDuck said:
Agreed. Definitely a case to forget the "protect the wiring" notion, because if more than maximum output is flowing you could have a broken regulator capable of doing nasty things long before the wires (which ought to be chunk) get anywhere near their capacity.
Click to expand...

The wiring needs to be protected not from the current from the solar system but current that can flow back from the battery. EG if the wires at the terminal block of the controller were to short together then the wiring to the battery would incandesce with battery current potentially causing a fire. hence ideally fuse should be at the battery terminal. olewill
 
William_H said:
The wiring needs to be protected not from the current from the solar system but current that can flow back from the battery. EG if the wires at the terminal block of the controller were to short together then the wiring to the battery would incandesce with battery current potentially causing a fire. hence ideally fuse should be at the battery terminal. olewill
Click to expand...

You misunderstand me, I think. My point is that serious damage, up to an including fire, could occur in a malfunctioning controller at currents well below those which would damage the wiring. Hence in this case the fuse is NOT there to protect the wiring.
 
JumbleDuck said:
Hence in this case the fuse is NOT there to protect the wiring.
Click to expand...
Well it does that as well,

The point Vyv and you make that the fuse should not have a higher rating than necessary is a valid one.

To avoid voltage drop the wiring will be heavier than is required for a safe current carrying capability. It would be a mistake for the reasons you highlight to similarly increase the fuse rating.
 
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