SCR-485 Install South West of Western Australia

Hi Everyone, (I have cut and pasted from a word doc not sure how the images will come across) 

My name is Colin, I am an electrician as well as a computer networking engineer which has been very helpful is putting my project together although having said that the software scripting has been driving me crazy with a lot of failures. So far it has been easier just to use other people’s yaml files.

The SCR_485 arrived a couple of weeks ago and I have finally found time to start the project, initially converting the box it came in into an enclosure to keep fingers away from the bitie bits.

Plugged into a power point with a 1000w QI flood light as the load with an IP camera monitoring the light.

Configured the WIFI to my access point and then started looking at ESPhome and Home Assist as how I was going to manage it..

This whole process took some time to get my head around ESPhome and Homeassist and in the end I took advice from Jack at DeviceIt and decided to drop the Homeassist and just run the Dashboard from ESPhome. Certainly, much easier for my testing and dumping yaml files onto the SCR. As mentioned, I started using the published yaml files with a few small mods that didn’t break anything and finally got my 1000watt QI light ramping up and own with the SCR connected to my WEM3080T.

I live in the southwest of Western Australia and our power supply from the grid is what as known as 500volt single phase, it comes from a centre tapped 11KV transformer, effectively, 2 x 250v feeds 180 degrees out of phase with 500volts between the outer points/phases, it is known as Rural Power and it is easy for the supply authority as they only have to run a single 11kv wire with an earth return. Every farm has its only 5/10/15KVA transformer, anyway, got off track there a little.

Bottom line is I needed the WEM3080T to cover the 2 x 250-volt feeds which are not phases like most people will know them, I have 2 separate 3KW Solar Inverters with 2 separate strings of Solar Panels, which knowing this will make my IAMMETER Graphs a little easier to understand later..

After a week or so testing as I could only do so on the weekends between other jobs on the farm, I finally got around to mounting the unit on a panel with a terminal box over bitie bits while leaving good ventilation around the fan assisted heat sink. Photos supplied. Oh! I forgot to mention I am not on the farm full time; I spend a few days a week at me real job in the city as that IT guy, but I have full remote access and make all the changes I need from my desk a couple of hundred kms away.

You will see from the photos, the terminal box on the SCR _485 has 2 x 15amp change over isolators and an incandescent globe to monitor the approximate voltage going to my 3.6kw Solar Hot Water System Booster Element. The 2 change over switches are 1) Removes the SCR_485 from the HWS circuit and powers the HWS direct with full 250 volts supply. 2) Changes the load side of the SCR_485 from one HWS to another.

Light full bright meaning full power going to the HWS

You will see from the attached Graph and turned the power on to the Solar Inverter and the SCR_485 around 12 midday and the usage dropped considerably and with the cloudy day the usage bounced above the line but very little below the line..

Today I leant all about Net Metering Mode from this great forum..

Net Metering for me is the resultant of both phases and not just the phase that the HWS is on. You WEM3080T users would have had to select the phase you wanted to use “If your solar PV uses phase A, it is ["Datas"][0][2], if it is phase B, it is ["Datas"][1][2], if it is phase C, it is ["Datas"] [2][2]”

This is how I turned it on

After which the includes resultant of all phases



// WEM3080T/WEM3050T/WEM3046T
if (root.containsKey("Datas") && root["Datas"].is<JsonArray>() && root["Datas"].size() > 2) {
// If your solar PV uses phase A, it is ["Datas"][0][2], if it is phase B, it is ["Datas"][1][2], if it is phase C, it is ["Datas"] [2][2], if it is phase A+B+C, it is ["Datas"] [3][2] if WEM3080T is used in NET Metering Mode
int32_t tmp_grid_power = root["Datas"][3][2];

Please see the graph after the Net Metering was implemented..

It was done late in the afternoon today and as such you don’t get to see much, but you can clearly see the resultant power flat line as power is poured into the HWS which I yet to log or monitor.. (looking for suggestions on that)

See below Web Browser connected to my SCR_485

I have debugging turned on as I like to watch..

I will ask some questions about the functions below in a later post..

Please let me know if I should be doing anything, it is all very new to me and will to learn more..

I hope I have not bored too many people.

So far it has been working well although it has only been a day..

Cheers all..


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Today's Graph showing great flat line

The interface showing 1455watts going into the HWS

Today's Graph showing great flat line

Hi Colin:

Your installation is very cool

Some questions

1 Your system is like the "120/240V " system in North America(A single-phase 3-wire system with two L lines and one neutral line, where the two high legs are 180 degrees out of phase ) , as described here. But your system is 250/500V, yes?

2 Phase A and Phase C are used to monitor the input of the two L lines, yes?

If you use the Net Metering mode, please enable the NEM switch in IAMMETER-cloud. You can follow the instructions in the link below. This will sum the power from all three phases and display a single power value (the total) on the chart.



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