Cam switch 20A, Three-phase starter switch (0,Y,A), \OB7/2 SK20-4.831\OB7/2

Universal star-delta starter for motors and more

This three-phase star-delta starter with a rated current of 20A is a reliable solution for controlling electrical circuits, especially in motor starting applications. The 0-Y-∆ (0-star-triangle) configuration effectively limits the inrush current, protecting both the motor and the electrical installation. It is suitable for both new installations and modernization of existing systems.

Construction and application

The SK20 OB7/2 star-delta starter features a robust construction and high resistance to environmental conditions. The enclosure with an IP65 protection rating ensures safe operation even in harsh industrial conditions – it is dustproof and water resistant. This switch finds application in:

• Starting three-phase motors (star-delta)
• Switching electrical circuits requiring high reliability
• Industrial applications where resistance to harsh conditions is required
• Control panels and electrical switchboards

Key features and benefits

• High switching endurance: Rated switching current up to 20A in AC-21A and AC-22A circuits guarantees stable operation even under heavy loads.
• Wide voltage range: Ability to operate at rated insulation voltage up to 690V and impulse voltage 4kV ensures versatility of application.
• Resistance to external conditions: IP65 protection rating protects against dust and water, increasing the durability of the device in demanding environments.
• Durable construction: Mechanical endurance of 3 million switching cycles ensures long life and minimizes the need for replacement.
• Safe operation: Compliance with safety standards (see section below) guarantees safe operation.
• Flexible mounting: Panel mounting (31/□36 hole) simplifies integration with existing systems.
• Suitable for operation in a wide temperature range: From -40°C to +70°C – both during operation and storage.

Operating parameters and compliance with standards

The starter meets the requirements of IEC standards, confirmed by the certificates held (CE, RU, UA). The short-time withstand current is 0.25kA, and the conventional short-circuit current is 10kA. The cross-section of the connecting wires is 1...4 mm², and the tightening torque of the terminals is 0.5 Nm. This makes installation simple and safe. Additionally, the device is resistant to vibrations and mechanical shocks, which increases its reliability in harsh industrial conditions.