An electric window actuator alone does not open a window. It needs a window control: it supplies the right voltage, gives the command to open or close and responds to push buttons, sensors or the building management system. This guide shows which parts a window control consists of, which variants exist and what to look for when choosing one.
In brief: A window control system supplies the right voltage, gives the command to open or close and responds to switches and sensors. 230 V actuators can be switched directly with a switch such as the VS-LT 230, while 24 V actuators need a control unit such as the VS-C24-7A. A ventilation control unit is not an SHEV control panel.
What is a window control?
Window control refers to everything between the mains supply and the window actuator that triggers the movement of the window. In the simplest case, this is a push button that switches a 230 V actuator directly. With 24 V actuators, a control unit is added that converts the mains voltage into 24 V DC and sets the direction of travel via the polarity. Larger systems are controlled via a ventilation control or the building management system.
The components of a window control
- Control unit or power supply: supplies 24 V actuators with power and switches open and close, for example the VS-C24-7A controller with 24 V / 7 A.
- Instructions: Wall-mounted ventilation buttons such as the VS-LT-A surface-mounted ventilation button or a radio remote control such as the VS-C24-F-1.
- Sensors: A Rain sensor or a Wind-rain-light sensor reports the weather to the control so that open windows close in time.
- Actuators: chain, spindle or rack-and-pinion actuators that move the window.
24 V or 230 V: which window control fits?
The voltage of the actuator determines the control. 230 V actuators can be switched directly with a suitable push button such as the VS-LT 230 , which is the simplest solution for single windows. 24 V actuators need a control unit, but are safer to handle, easy to connect in parallel and easy to combine with sensors. For systems with several windows and weather protection, 24 V is usually the better choice. More on this in the guide Window actuator 24 V or 230 V.
Typical variants
Single window via push button
A top-hung window or roof window is opened at the push of a button. With 230 V a ventilation button is enough, with 24 V the control unit is added.
Several windows together
Several 24 V actuators are connected to one control and move at the same time. It is important that the combined current of all actuators stays below the rating of the control unit. On large sashes with two actuators, tandem or synchronous operation ensures even opening, see tandem operation.
Automatic ventilation with weather protection
Sensors close the windows automatically in rain or wind. How a rain sensor works and where it belongs is explained in the guide Rain sensor for windows. This means a window can stay open even when nobody is in the room. The guide shows how this works in practice: Ventilation control for window actuators.
Connection to the building management system
In office buildings, schools and halls, windows are often controlled centrally via KNX or another building management system, for example for night-time cooling. You will find information on this in the article Integrating window drives into building management systems.
Window control and SHEV: the difference
A window control for daily ventilation is not a SHEV control. Windows that are to extract smoke in the event of fire need an approved SHEV control panel with emergency power supply, smoke detectors and fire brigade button. Actuator, window and control panel are then matched and certified for the specific project. Our controls are intended for comfort ventilation. More on this topic in the guide SHEV and daily ventilation.
Checklist for selection
- What voltage do the actuators have: 24 V or 230 V?
- How many actuators are to be connected to one control, and how high is their combined current?
- Should control be via push button, radio or automatic?
- Are rain or wind sensors required?
- Is a connection to KNX or a building management system planned?
- Does the window also have to serve smoke extraction? Then a SHEV control panel is required.
Read more: Window Actuators and Burglary Protection: Tightness, Locking, Power Failure
Suitable control: the VS-C24-7A controller It drives up to 10 drives together (depending on the power consumption), plus shutters and roller shutters. More about it: Windows, blinds and roller shutters controlled by 24 V.
If an actuator no longer responds, our guide helps: Window actuator won’t open.
Frequently asked questions
Can I connect several window actuators to one control?
Yes, this is common with 24 V actuators. Add up the rated current of all actuators and choose a control with sufficient power and some reserve.
Do I need a control for a 230 V actuator?
For a single window, a suitable ventilation button is sufficient. If sensors or several windows are to be integrated, a control makes sense.
Can windows be opened by radio?
Yes. The VS-C24-7A can be operated with the VS-C24-F-1 radio remote control, which is practical for high windows without a push button within reach.
Do I need special cables and switches?
With 24 V actuators, the cable cross-section is particularly important because voltage is lost over long cables. Operation is via a control unit with push button. 230 V actuators need a push button with mutual interlocking, as with blinds, so that both directions never receive power at the same time. The connection must be made by a qualified electrician.
Suitable products and advice
You will find all controls, push buttons and sensors in the category Window control and ventilation control, the actuators under Chain drives, Spindle drives and Rack-and-pinion drives. Not sure which combination fits? Write to us via the Contact form, and we will put together the right window control for you.