Smart Home, Building Automation (BMS) & Security
Return to category.
Go to categoryElectric Roller Blinds & Awnings: 4-wire motor connection (Standard) with smart shade switches and limit calibration
Controlling the natural light and heat that enters your home is probably the most underrated energy saving factor. In summer, a lowered awning saves the air conditioner from hours of hard work, while in winter, open blinds at midday "capture" the sun's free heat (solar gains).
But to achieve absolute control, your electric roller blinds and awnings must become "smart". Many times, consumers buy expensive motors with their own closed remote controls, making their integration into the Smart Home a real nightmare.
As engineers, our advice at the beginning of every project is one: Choose the most "simple", standard (Standard) motors on the market. We will not get the "intelligence" from the motor, but from the switch that we will put on the wall. Let's see how they are connected and how they are regulated.
1. The "Standard" 4-Wire Motor (How It Works)
If you buy a classic, tubular motor for your roller (e.g. from Somfy or other companies) without built-in remote control receivers, the cable coming out of the motor has 4 individual wires (conductors) inside it:
- Ground (Yellow-Green): For safety (goes to the motor chassis).
- Neutral (Blue): Return of current.
- Directional Phase 1 / Up (Usually Brown): When you apply power to this wire, the motor turns clockwise and the roll goes up.
- Directional Phase 2 / Cathode (Usually Black): When you apply power to this wire, the motor turns counterclockwise and the roller descends.
Attention: Top/Bottom colors may vary depending on which side of the window the motor is mounted on, so we always test.
2. The Absolute Security Requirement: Interlock
What happens if you apply current to both the Brown (Anode) and Black (Cathode) wires at the same time? The motor will try to turn in both directions at once, the coils will overheat, and the motor will burn out.
To avoid this, classic wall roller switches have a mechanical barrier (Interlocking). They don't let you press "Up" and "Down" together.
When we make the shutters smart, we use special Smart Shutter Relays (Roller Shutter Modules, e.g. Shelly Plus 2PM, Fibaro Roller Shutter) or special smart shade switches. These devices have TWO power outputs (O1 and O2) and have built-in Software & Hardware Interlock circuitry. Even if the system "stuck" or someone pressed all the buttons at the same time, the relay will never let current pass through both outputs at the same time. Thus saving your motor.
3. Connections (How we "marry" the Relay with the Motor)
If you put a smart relay (like the Shelly Plus 2PM) behind your traditional roller switch, the connection (simplified) looks like this:
- Power supply: We bring permanent Phase (L) and Neutral (N) from the panel to the smart relay. Neutral goes directly to the blue motor wire as well.
- The Commands (Switch): The two buttons of your physical switch are connected to the two inputs of the relay (S1 for Up, S2 for Down).
- The Outputs (Motor): We connect Output 1 (O1) of the relay to the Brown cable of the motor (Anode) and Output 2 (O2) to the Black cable (Cathode).
Now, when you press the switch (or give a command from the mobile), the smart relay safely supplies power to the corresponding motor wire.
4. Calibration: Why is it Necessary?
You have made the connection and you press the "Upgrade" button. The roll goes all the way up, hits its natural limit switch, and the motor stops.
Here's a problem: The smart relay doesn't "see" the roll. He doesn't know that the roll has stopped. It keeps sending power! Also, if you tell it to "Open the roll to 50%", how will it know exactly where 50% is since it has no "eyes"?
The solution is Calibration. Quality relays have a built-in power meter (Power Metering).
The process: Through the mobile application, you press the "Calibration" option. The relay does the following by itself:
- Gives a command to Ascend.
- It measures that the motor "draws" current (e.g. 150 Watt).
- When the roll ends up, the motor's physical switch cuts the power. The relay sees the consumption drop sharply to zero (0W) and "understands" that this is the "0% Position".
- He then commands a Descent. It counts the time (eg 20 seconds) until it bottoms out, where the consumption drops back to 0W. This is "Position 100%".
- He runs the route 1-2 more times to confirm the time to the millisecond.
The Result: Now, the smart relay has "learned" that it takes 20 seconds for the roller to go from 0 to 100%. When you tell it "Alexa, open the roller blind to 50%", the relay will power the motor for exactly 10 seconds! Control is now absolute.
Summarizing
To get the perfect smart roller blinds, the rule is not to buy motors with integrated radio frequency boards and closed remote controls. Go for the absolutely "dumb" and cheaper, 4-wire wired motors. By placing a quality relay with Calibration function behind them, you turn the heaviest metal roller into a high-precision device, ready to be integrated into your home automation.
Next Step: Now that the blinds and awnings "listen" to our commands in percentages, how can we get the weather to move them for us?
We continue to perhaps the most impressive scenario of a smart home: Smart Shading based on Weather Conditions: How to set the automatic closing of the awning in strong wind and the lowering of the blinds in the hot sun.
Related Articles
Smart Shading Based on Weather Conditions: How to set the awning to automatically close in strong wind and roll down in hot sun Smart Climate Control (A/C & Heat Pumps): From simple Smart IR controllers to advanced KNX/Modbus thermostats Battery-Free (Kinetic/Piezo) Wireless Switches: How They Work, Where They Solve Hands, and How They Eliminate Digging Into Walls DIN Rail Equipment (e.g. Shelly Pro): Professional smart installations directly inside the central electrical panel
Central Guide
Return to the central guide.
Go to guide