In this article:
- Overview
- Wiring Diagram
- Functional Description
- Settings Required
Overview
The following wiring diagram shows a suggested application and are examples only; there are many more possibilities.
Please take a look at the Safety section within the installation manual and read all the installation sections before attempting to install the eddi.
A good level of electrical competence and a reasonable understanding of domestic plumbing systems is assumed for studying this application example.
Wiring Diagram
| Key for Wiring Diagram | |
| 1 - eddi device | 2 - Mains supply (230V AC from B16 circuit breaker or 13A fused spur) |
| 3 - Hot Water cylinder | 4 - Heating element 1 (max. 3.7kW) |
| 5 - Isolator (20A double pole) | 6 - Relay & Sensor Board (optional add-on for eddi) |
| 7 - Temperature probe (type PT1000) (optional) | 8 - S-Plan wiring centre |
| 9 - Auxiliary water heating boiler | |
Functional Description
As eddi is predominately a water heating control device, it can be used to manage all of the water heating, even if an auxiliary heat source is used to heat the water. With this application, the homeowner will be able to program auxiliary boiler boost times with eddi.
In the UK a popular plumbing and wiring scheme used by central heating systems is referred to as 'S-Plan'. This scheme usually has a standard junction box which eddi can be wired to, to enable the programming of water heating times with the BOOST TIMER feature of the eddi.
The water heating element (4) is wired to the Heater 1 output and Relay 1 of the Relay & Sensor Board (6) is wired to the SPlan wiring centre (8). Any existing water heating control is removed or disconnected.
The water in the cylinder (3) is heated with only surplus power until the thermostat has opened, the eddi will display Max Temp Reached and the surplus power will then be exported until the water cools, and heating will then resume.
The BOOST TIMER (RELAY 1) in the eddi is used to program the auxiliary heat source (e.g. a gas boiler) to heat the water either early in the morning or later in the evening, depending on the home owner's lifestyle. Heating the water during times of generation (e.g. daylight hours) is best avoided to allow maximum capacity for the surplus energy.
Whenever the boost is active, Relay 1 will operate and the S-plan heating system will respond, heating the water via the auxiliary boiler.
The BOOST TIMER (HEATER 1) can be used if it is desired to boost water heating with the immersion heater.
Installation of the temperature probe (7) is optional; the immersion heaters' mechanical thermostat is used by eddi if a water temperature reading is not required.
Settings Required