Siemens Industrial Controls 3RU2136-4HB0 Thermal Overload Relay Size Class - 40-50A S2 10

The Siemens 3RU2136-4HB0 is a SIRIUS thermal overload relay designed to provide reliable current-dependent motor protection against overload conditions and phase failure. This Class 10 relay features an adjustable current range of 40-50 amperes and is specifically engineered for mounting on Sirius 3RT203 size S2 contactors, including models 3RT2035, 3RT2036, 3RT2037, and 3RT2038.

Key Features:

• Adjustable current range: 40-50A for precise motor protection
• Class 10 trip rating - trips in 10 seconds or less at overload conditions
• Maximum rated operating voltage: 690V
• Two auxiliary contacts: one normally open (1NO) and one normally closed (1NC)
• Manual or automatic reset functionality via selector switch
• Phase failure protection to minimize heating during single-phase operation
• Temperature compensated trip range: -20°C to +60°C
• Screw terminal connections for main and auxiliary circuits
• Switch position indicator for trip fault indication
• Suitable for operation with frequency converters

This thermal overload relay uses bimetal strip technology that responds to current rises by heating and bending to trigger the auxiliary contacts, which then switch off the load through the contactor. The device meets IEC947, VDE0990, and EN60947 standards, with 6kV impulse voltage resistance and 690V insulation voltage rating. Ideal for industrial motor protection applications requiring reliable overload and phase loss protection.