Heat pump control
Control your SG-Ready heat pump with Shelly
Smart Grid Ready – SG Ready – is a designation for an installation, such as a heat pump or solar panel system, that is prepared for the smart electrical grid. This allows the supplier to control the heat pump in cases of surplus or deficit of electricity on the grid.
The SG Ready Label is awarded to heat pumps that can be controlled via two signals (2 bits) to operate in four different modes. Besides normal operation, there are three additional settings to either turn on at full power, slightly increase operation, or stop completely.
Link to a list of most SG Ready heat pumps (in German):
https://www.waermepumpe.de/normen-technik/sg-ready/sg-ready-datenbank/
What you will need
Shelly Pro 3EM
To measure how much electricity we import/export from the grid, we need to use a Shelly Pro 3EM.
The Shelly Pro 3EM should be installed between the meter and the supply side of the RCD.
It is important that the current transformers face the right direction and the Pro 3EM device is supplied with the respective phases.
Technical documentation: Shelly Pro 3EM
1 x Shelly Pro 2 or 2 x Shelly Plus 1
Since two terminal sets need to be connected to control the desired function in the heat pump, we require two potential-free contact sets. For this, a single Shelly Pro 2, which has two dry contacts and is DIN-rail compatible, can be used, or two Shelly Plus 1s, each with a built-in dry contact.
Technical documentation: Shelly Pro 2
Technical documentation: Shelly Plus 1
Wiring diagram for SG-1 and SG-2 terminals
It may be necessary to select the different functions by connecting SG-1 and SG-2 within the heat pump’s menu function. Additionally, some manufacturers use different naming for SG-1 and SG-2.
Shelly Pro 2
Shelly Plus 1
Create an automation that turns the heat pump on and off during electricity overproduction
Now, you need to create two scenes:
- One that activates the boost function during excess electricity production.
- Another that returns to normal operation during reduced electricity production.
Shelly refers to automations as Scenes, and these can be created both through the Shelly Smart Control app and at https://control.shelly.cloud.
Scene 1: activate boost-mode
To create a scene to activate boost mode, you need the following settings:
WHEN:
- Shelly Pro 3EM – Sum of all phases – less than -1000W*
DO:
- Switch on Shelly Pro 2, SG-1
- Switch on Shelly Pro 2, SG-2
*You will need to define the power consumption that fits your wishes.
Scene 2: activte normal mode
To create a scene to activate normal mode, you need the following settings:
WHEN:
- Shelly Pro 3EM – Sum of all phases – more than 500W*
DO:
- Switch off Shelly Pro 2, SG-1
- Switch off Shelly Pro 2, SG-2
*You will need to define the power consumption that fits your wishes.
Done
You are now done. Your heat pump will now switch to boost mode when your solar panels are producing more energy than you are using. This should hopefully save you a lot of money.