Increasing capacity of 20A solar regulator

[tarbaby]

Well thanks to T1 Terry, I have almost finished rejigging my solar setup. It works great

I now have 900 watts of solar (6 X 150 watt panels) on the roof, controlled by the Dingo 20, feeding 240Ah of AGM batteries.

This (with Terry's advice and improvements) is what I did:

Dingo 0 current SSR all current.jpg

There is also a Victron BMV700 on the neg side

Look at those electrons go!:

volts amps.jpg

40+ amps, hazy cloud, fridge sucking in 5-6 amps, I am happy with that

This is what the circuit diagram looks like in real life:

wiring.jpg

The wiring needs a bit of a tidy up, and some labeling would be good. There is a fan wired to the SSR heat sink thermo switch (now I know what a tunnel heat sink is ). I was planning on installing lifepo4 batteries, but when buying time came, there were no Winston cells available in Aus and we needed to use the van so bought a couple of cheap AGMs instead. We only use the van a couple of weeks a year, but when we go touring in a couple of years time will upgrade capacity and get lithium batteries. There is plenty of room to install relays/disconnects etc.

Thanks for your help Terry!

[bagmaker]

Good stuff! That T1 is a whizz isn't he?
I would like to see that heatsink spun 90 degrees to improve the airflow around it though!
I made one up from a bit of 50mm sq. aluminium, some more ally in the guts of that and a fan at the top -will get a photo for you.

Does the Dingo need its own shunt?

[grizzzman]

Well thanks to T1 Terry, I have almost finished rejigging my solar setup. It works great

I now have 900 watts of solar (6 X 150 watt panels) on the roof, controlled by the Dingo 20, feeding 240Ah of AGM batteries.

This (with Terry's advice and improvements) is what I did:
Dingo 0 current SSR all current.jpg
There is also a Victron BMV700 on the neg side

Look at those electrons go!:
volts amps.jpg
40+ amps, hazy cloud, fridge sucking in 5-6 amps, I am happy with that

This is what the circuit diagram looks like in real life:
wiring.jpg

The wiring needs a bit of a tidy up, and some labeling would be good. There is a fan wired to the SSR heat sink thermo switch (now I know what a tunnel heat sink is ). I was planning on installing lifepo4 batteries, but when buying time came, there were no Winston cells available in Aus and we needed to use the van so bought a couple of cheap AGMs instead. We only use the van a couple of weeks a year, but when we go touring in a couple of years time will upgrade capacity and get lithium batteries. There is plenty of room to install relays/disconnects etc.

Thanks for your help Terry!

Is it the "load" terminal's on the charge controller that the SSR is connected to? Is the resistor to reduce the heat produced by the SSR during switching or perhaps to switch cleaner?

Thanks

[tarbaby]

I would like to see that heatsink spun 90 degrees to improve the airflow around it though!
I made one up from a bit of 50mm sq. aluminium, some more ally in the guts of that and a fan at the top -will get a photo for you.
Does the Dingo need its own shunt?

I wondered about which way to place the heatsink, but thought that air flow across it would be more effective in line. I was expecting the SSR to get hot when switching 40+ amps, but surprisingly neither it nor the heatsink seem warmer than its surroundings. Maybe I will have to wait until air temps here get up there, its only 20-25 degrees here atm.
Yes, I would like to see the photo of your heatsink. The tunnel heatsink/fan combo that Terry recommended is this one I think:
https://www.jaycar.com.au/fan-assisted- ... g/p/HH8532
I made up a fan shroud for a 120mm fan on the compartment vent that is switched via a 45 degree thermo switch riveted to the SSR heatsink:

2312_fanshroud_1.jpg

Of course, it hasnt been hot enough for it to turn on yet, I will wait and see how successful it is, I may go for the Jaycar fan assisted job yet.

The Dingo needs a shunt. It came with a 200 amp shunt which I between the placed between the battery+ve and the charge bus. Not sure if this is the best spot for it, I would like to use it to measure charges only, not charges and loads. I have a Victron BMV700 shunt on the battery negative side which does exactly the same thing, no point in duplicating it!

Is it the "load" terminal's on the charge controller that the SSR is connected to? Is the resistor to reduce the heat produced by the SSR during switching or perhaps to switch cleaner?

yes, the SSR is switched via the load terminal on the controller, and the solar current goes directly to the SSR, then battery, so that no current goes via the controller. I am not sure of the function of the resistor, you will have to ask T1 Terry for a better explanation! I think that it is to put some significant load onto the controller to make it as you say, switch cleaner. Rainbow Power Company do a similar arrangement with the same controller:
http://www.rpc.com.au/pdf/dingo_20_relay.pdf
I put the resistor across the terminals at the controller:

2312_dingo_load_resist_1.jpg

[T1 Terry]

It's all to do with how the controller is programmed and very few controllers can be programmed this way so we use the Plasmatronics controllers exclusively if we want to use this control method. Basically, the resistor is to stop a dead short, it is all in the way the controller drives the solid state relay/s, if you understand how electronic control works the wiring diagram is self explanatory, if you don't then best to leave it to someone who does understand as the smoke won't go back in once it gets out

T1 Terry

[Jon and Kay]

I wondered about which way to place the heatsink, but thought that air flow across it would be more effective in line. I was expecting the SSR to get hot when switching 40+ amps, but surprisingly neither it nor the heatsink seem warmer than its surroundings. Maybe I will have to wait until air temps here get up there, its only 20-25 degrees here atm

I also experience very little heat from the SSR used in this way. The PL40 used to get much hotter at 40A than the SSR does at 70A

[bagmaker]

here you go Tarbaby
I put this system in expecting the original MPPT regs to fail but got them to work OK. When we either 1- get more solar or 2- get Li batts then we are already half way to installation so I will leave it all in place

SSR on heatsink.jpg

The heatsink is 800 long. I dont expect it will ever need the fan but oh well, cheap insurance
Thermostat is 50 degree. There is room on the bottom for another 100A SSR -redundancy or overengineering, take your pick

heatsink top.jpg

[tarbaby]

Thanks for confirming this Jon and Kay. My SSR came from Jaycar, perhaps they are just good quality.

Hey Bagmaker, thanks for the photos. Yours is 800 long? I'm impressed
Thats a lot of heat disappation. Do you need the fan? Will it ever run?
Could you run your solar through the SSR controlled by the mppt regulator load circuit, or are they not capable of this?

[Jon and Kay]

Thanks for confirming this Jon and Kay. My SSR came from Jaycar, perhaps they are just good quality.

Hey Bagmaker, thanks for the photos. Yours is 800 long? I'm impressed
Thats a lot of heat disappation. Do you need the fan? Will it ever run?
Could you run your solar through the SSR controlled by the mppt regulator load circuit, or are they not capable of this?

My SSR was sourced from Jaycar, with a matching heat sink which is very similar to the PL40 (same size and colour). Jaycar sourced them for this purpose.

[T1 Terry]

This tunnel heat sink has 4 x 100 amp solid state relays and the Dingo above controls them. There is 3200w of solar @ 12v connected via this control method and recently an 8kW inverter air con system was added, this is a stand alone house system a long way from the grid. The solar cabling now gets rather hot when the air con is running because it now has something to do rather than top up the 700Ah of lithium batteries, so we will be upgrading the solar cabling, the previous installers for the other 2 parts of the solar system were a tad clueless when it came to wiring requirements. The heatsink rarely starts the fan up and is auto switched by 2 x 50*C thermostats.
The recently fitted 1900w semi flexible solar install on the 5th wheeler has a similar set up, the relays now supplied by Jaycar died within 3 days and had the fan running almost full time, once replaced with the earlier supplied solid state relays the problems disappeared and the fan does not start up at all.
Can you imagine the size of the MPPT controller required for 3200w of solar @ 12v wired in parallel

T1 Terry
Be better if I add the photos eh

4 x 100 amp SSR tunnel heatsink.jpg