Siemens 3RU21264DB0 20-25A Thermal Overload Relay

Siemens 3RU21264DB0 20-25A Thermal Overload Relay 

This device protects electric motors from damage caused by too much current or phase loss. It automatically stops the motor if it detects a problem.

Key Features:

Protects motors with current from 20 to 25 amps

Trips quickly (about 10 seconds) when overloaded (Class 10 trip)

Can be reset manually or automatically

Mounts directly on Siemens SIRIUS contactors (Size S0)

Easy to connect with screw terminals

Safe to use indoors with finger protection (IP20 rating)

Works in temperatures from -40°C to 70°C

Rated voltage up to 690 VAC

Dimensions: approximately 85 × 45 × 85 mm

Weight: about 0.19 kg (0.42 lbs)

How It Works:

If the motor draws too much current or loses a phase, the relay senses this and cuts power to the motor to prevent damage. You can see when it trips and reset it after fixing the issue.