Cam switch 20A, Dahlander two-speed switch, base rail mounting front grey knob black SK20-4.8390\BS23

Universal reversing cam switch for motor control

This dual-speed reversing cam switch, also known as a Dahlander switch, is a reliable solution for changing the direction of rotation or speed of electric motors. Designed for both professional and end-user applications, it offers simple operation and a durable construction. Rail mounting allows for easy integration with existing electrical infrastructure.

Construction and application

The SK20-4.8390.BS23 switch is made of high-quality plastic, which ensures its strength and resistance to mechanical damage. Designed for front mounting on a rail base, which facilitates installation and servicing. A black knob provides convenient and intuitive operation. It finds application in controlling electric motors in various devices and machines, such as:

• Ventilation and air conditioning systems
• Pumps
• Gate and roller shutter drives
• Industrial machines
• Lifting equipment

Key features and benefits

• Durability and reliability: Plastic construction guarantees long-term operation even in harsh conditions.
• Versatility: The Dahlander switch allows you to change the direction of rotation or speed of the motor, increasing its functionality.
• Easy installation: Rail mounting on TH35 simplifies installation and integration with existing electrical installation.
• Safety: IP65 protection rating provides protection against dust and water jets, increasing safety.
• Suitable for loads: Rated continuous current of 20A and the ability to operate at 690V allow use with various types of motors.
• Wide temperature range: The ability to operate at temperatures from -40°C to +70°C makes it suitable for use in various environments.
• High resistance: Meets IEC standards regarding resistance to vibration, shock and environmental factors.

Operating parameters

The switch is designed to operate in circuits with a rated insulation voltage of 690V and a rated impulse withstand voltage of 4kV. The rated operating power for AC-3 is 4kW at 400V, making it suitable for most standard industrial and domestic applications. The rated short-circuit current is 10kA, providing effective protection against the effects of short circuits. The cross-section of the connection wires is 1...4 mm², and the tightening torque of the terminals is 0.5 Nm – which facilitates correct connection of the wires.