Wiring diagram help

[Pazza72]

I need help with the wiring.

Can someone suggest a wiring diagram for the following components:
120W solar panel to 16amp breaker to controller to 40amp breaker to 12v battery
I will also connect a 12 fused bus bar to the controller as well.

I have looked at many diagrams online which seem to make sense but some seem to contradict others and this confused me so here I am to get help and best practice.

Thanks

 

[sun walker]

can you post a couple of those diagrams?

 

[mikefitz]

120W solar panel to 16amp breaker to controller to 40amp breaker to 12v battery

In the UK its expensive to get well designed DC breakers, the low cost Chinese readily available are unsafe, use a fuse .
For a single panel 120 watt conection to a controller a breaker is not really necessary, a direct conection to the controler will be OK. If you need isolation any 10 amp DC switch could be used. It's only where larger higher voltage solar arrays are used that isolation breakers will be useful.
Any cable connected to the battery needs overcurrent protection suitable for that cable, installed as close as practical to the battery. So for the solar ontroller with the 120 watt panel, the maximum current will be 10 amps. Fuse at 15 amps and use 4 or 6mm2 cable.

The accessory fuse block will be fused suitable for each accessory, connect to the battery with a suitable fuse at the battery, typically this will be a 30 or 50 amp fuse.

Post a diagram indicating your design and it can be discussed. Details of the parts you area using, battery type and Ah, charger, and details of accessory power needed, will be useful.

 

[Pazza72]

Hi

Thank for the reply, here is attached a quick diagram. Main questions are:
- is a breaker required from panel to controller if so is my wiring diagram correct re: postive and negative?
- Is a battery fuse to breaker required close to the battery on the postive terminal?
- Where do I connect the postive and negative terminals of the bus bar to the system?

 

[eppich8479]

I have 8x400w panels connected to a pv combiner from china. 2s4p and i dont think my fuses are a problem. At 1x 120w panel i think you are trying to solve a problem that doesnt exist. 120w at 12v is nothing

 

[wheelman55]

What are your distances?

1. Panel to controller
2. Controller to battery
3. Battery to busbar
4. Busbar to loads

What battery will you use?

In general:
- use copper stranded wire.
- 10 AWG wire from panel to battery should be good.
- Size your breaker to be compatible with wire size from battery to busbar.
- 40 amp breaker for 8 AWG wire.
- 50 amp breaker for 6 AWG wire

Above wire sizes are for pure copper wire.

I prefer fine stranded wire.

Marine supply houses should sell all of the parts that you need, including breakers, wire, lugs, busbars, etc.

You have a small system. Use quality bits.

What are you hoping to power with your system?

I used a simple system like this for several years to charge 2 phones, 1 laptop, 2 tablets and power a small 12 volt fan.

I was able to keep two batteries charged. A 100 ah lithium and a pair of Trojan T-105 6 volt 220 ah lead acid batteries.

My system consisted of panel, pwm controller, 10 AWG to battery, 8 AWG to 40 amp breaker, 8 gauge to busbar, smaller wire to loads.

I powered a mix of 12 volt marine outlets, usb outlets and switch to the small fan.

I used Blue Sea products. The fan was a super efficient and effective marine fan.

If your panel is mobile you can keep it aimed at the sun to max production.

Good luck!

 

[Pazza72]

Hi. Thanks for reply, here are answers to your questions. Many Thanks

1. Panel to controller - 0.5m
2. Controller to battery - 1m
3. Battery to busbar - 1m
4. Busbar to loads - varies 3 to 6 metres

What are you hoping to power with your system?
Small garden pond pump - 60W
Garden lightning - 4 x 5W each

What battery will you use?
SuperBatt Silver 9000 12V 50AH

 

[mikefitz]

attached a quick diagram

Solar panel direct to the controller, no breaker needed.
Controller outputs to battery, in line fuse as close as possible to battery positive, 30A. Use this,

Midi Link Fuses

Midi link fuses used for protecting larger current circuits in automotive, marine and leisure applications. Available in current ratings from 30A to 150A.

www.12voltplanet.co.uk

In this holder

Midi/Strip Link Fuse Holder

Single midi/strip link fuse holder with protective cover. Fuse & cable are secured via 2 x M5 studs. Cable size for this holder is 16mm² max.

www.12voltplanet.co.uk

To feed the acessories use a fuse box like, 6 or 12 way,

Ripca Standard Blade Fuse Box With Positive & Negative Busbars & LEDs - 6 Way

Blade fuse box with 6 circuits, positive & negative busbars & LED blown fuse indication. Includes sticker set & fixings. Ideal for campervan & motorhome wiring.

www.12voltplanet.co.uk

On this fuse box, the top stud is negative, connects to battery negative, the bottom stud connects to battery positive via a fuse 30A ( the same type as used for the controller).

In your fuse box use a 10A fuse for the pump and 5 amp fuse for each light.

If your solar charger has load outputs then your fuse box could be connected to those outputs of the controller rather than direct to the battery. What controller do you have?

 

[Pazza72]

Super answers Mikefitz.

The controller I have is https://uk.eco-worthy.com/products/...oogle Shopping&stkn=64d067d8541c&gad_source=1

 

[Pazza72]

Based on MikeFitz recommendations this is a revised wiring diagram.

 

[Pazza72]

Does the above diagram make sense?

 

[sun walker]

120W solar panel to 16amp breaker to controller to 40amp breaker to 12v battery

Its kinda straight forward, 120w pv is small, you got a red + & black - wires coming out of it, then next connect your 16amp breaker (Leave Breaker open, disconnected! some controllers need to have batt connected 1st - live before you turn on your pv) (just the + line if it has only 1 terminal or + & - if it has 2 terminals (always + to + & - to -), take the + & - from the breaker & connect to your controller (should have a pv terminal for + & - to screw on to) then take the batt + & - wires to your battery (good idea to have a large battery switch between the controller & batt to disconnect the + lead) connect your home up to the controllers Load + , - (good idea to have a Batt switch in the house line & maybe a 10 - 20 Amp car fuse- depending on your controller specs). I don't know your controller but most have separate screw terminals for Load, Batt & PV.
You may need to connect your inverter directly to the battery (again good idea to have a good battery disconnect switch in the + line & solid ceramic fuse slightly higher than you amp draw ). I guess that's where you may use your bus bar, but for 120w pv its probably not needed.