Now we have all the parts
This was written long before the units was installed. I made major changes to the wiring to improve saftey and make the installations more standard. These changes are shown in a later post was part of the installations.
Key differences
| Intital Build (here) | Install Build (later post) |
| Quick check to see that the basic idea worked and I could control the 20 Amp contactor via software. | Ensure that electricians would be able to understand the layout and wiring without the need for documentation |
| Live and Neutral Bus Bar used for speed to test more dangerous than the Earth plus Netural used in the final build. Note for my test I did not use an earth as I was only switching a LED. | Earth and Neutral Bus Bar used for final build. Important that high power installations have a good earth |
| Sonoff Basic on DIN Rail | Added 63Amp Isolotor so Sonoff move to base of CU. |
| Wired for speed of construction for testing | Wired with power coming in at the top of the Isolator. Sonoff and Contactor Power input live and neutral via MCB. MCB would isolate live from Contactor Sonoff and Imersion heater. Isolator would isolare Live and Netrual to all devices including the MCB |
The Sonoff Basic reflashed and configured as a web server with MQTT support. So not only can we operate it from the local network. The Web Sevice provides a simple ON / OFF control and the MTQQ fires a message to a broker then the unit turns On or Off. This is important as it lets us separate the control plane from the monitoring. Monitoring will be used to log data that can be used for AI, Reporting and Dashboards.
The cloud-based software that came on the device has been replaced so now there is no need to have an internet connection. This is important as if the internet connection failed the unit will still operate. This was not the case with the original could based software. (Yes we can still integrate with Alexa etc if needed) However, the dependency on the internet for control and monitoring is now removed
- Control Plane - Logical Layer used to control devices (Turn heater On and Off)
- Monitoring Plane - Logical Layer that records events (Heat turned on and Heater Turned off)
This layering separates the functions. Monitoring is important as we need to record not only when a device was turned on but by whom (AI or Rules Engine or Human via button/phone/internet which user? or timer?) If it was a machine the reason needs to be recorded too so we can debug/understand what is going on.
The cloud-based software that came on the device has been replaced so now there is no need to have an internet connection. This is important as if the internet connection failed the unit will still operate. This was not the case with the original could based software. (Yes we can still integrate with Alexa etc if needed) However, the dependency on the internet for control and monitoring is now removed
We have the contactor, a dial pole 20Amp ACa rated device. ACa is a slight inductive load or a mainly resistive load. The device is rated 7Amps ACb for resistive motor loads.
In this photo, you can see the live bus bar is fed from the output of the 16AMP MCB. Also, the multi-core copper wire is terminated and crimped to prevent shorts from copper whiskers
With consumer units the power normally comes in from the top, the neutral is connected directly to the neutral bus bar and the live to the base of the MCB /RCBO array. The switched live emerges at the top of each MCB/RCBO. We have used this traditional layout.
On the switched live bus bar you can see the feed from the RCB, the crimped live feed to the Sonoff and the feed to the base of the contactor. The output of the contactor has not been wired and the cables have not been trimmed to size or secured.
In this photo, you can see the live bus bar is fed from the output of the 16AMP MCB. Also, the multi-core copper wire is terminated and crimped to prevent shorts from copper whiskers
Test cable, note we need to connect the earth when it's wired to the heater. No earth needed for testing as the load was an LED light (Not shown)
With consumer units the power normally comes in from the top, the neutral is connected directly to the neutral bus bar and the live to the base of the MCB /RCBO array. The switched live emerges at the top of each MCB/RCBO. We have used this traditional layout.
When testing the cover for fitting you can see that plastic breakouts removed to fit all the devices have left a rough edge which will be filed smooth
