Microprocessor based overload relay - 3RB (Class 10E) - 3RB3026-1PB0

Product Description

Siemens 3RB3026-1PB0 Electronic Overload Relay – Class 10E Motor Protection for Industrial Applications

The Siemens 3RB3026-1PB0 Electronic Overload Relay is a high-precision microprocessor-based motor protection device from the trusted SIRIUS 3RB3 series, designed to protect three-phase motors against overload, phase failure, and phase asymmetry. Featuring a 1A to 4A adjustable current range, Class 10E tripping characteristic, and compact S0 frame size, this relay provides reliable motor protection for industrial automation systems, control panels, OEM machinery, and motor starter assemblies.

Unlike conventional thermal overload relays that rely on bimetallic elements, the Siemens 3RB3026-1PB0 uses advanced electronic current sensing and microprocessor-controlled evaluation technology. This intelligent design continuously monitors motor current and thermal conditions to provide highly accurate protection against overload situations. By detecting abnormal operating conditions before excessive heat can damage motor windings or insulation, the relay helps extend motor life, reduce maintenance costs, and minimize unplanned downtime.

The relay incorporates a Class 10E tripping characteristic, making it particularly suitable for motors with normal starting conditions. Class 10E protection offers rapid response to overload conditions while allowing standard motor acceleration without nuisance tripping. This makes the relay ideal for applications such as pumps, fans, compressors, conveyors, HVAC systems, packaging equipment, and general industrial machinery.

With an adjustable current setting range of 1A to 4A, the 3RB3026-1PB0 is ideal for protecting smaller three-phase motors and specialized industrial equipment. Siemens specifies motor ratings of approximately 0.37–1.5 kW at 400V, 0.37–2.2 kW at 500V, and 0.55–3 kW at 690V, providing excellent flexibility for panel builders and machine manufacturers.

A key advantage of the Siemens 3RB3026-1PB0 Motor Protection Relay is its integrated phase failure and phase asymmetry protection. The relay continuously monitors all three phases and automatically disconnects the motor if phase loss or significant imbalance occurs. This proactive protection helps prevent overheating, winding damage, and costly motor failures caused by single-phasing conditions.

The relay is designed for direct mounting onto compatible Siemens S0 frame contactors, creating a compact and efficient motor starter solution. Its robust screw-terminal connections for both main and auxiliary circuits ensure secure wiring, excellent vibration resistance, and long-term reliability in industrial environments.

For enhanced monitoring and automation integration, the relay includes 1 Normally Open (1NO) and 1 Normally Closed (1NC) auxiliary contacts. These contacts can be used for overload trip indication, PLC interfacing, alarm signaling, remote monitoring, and control circuit interruption. The integrated contact arrangement simplifies panel wiring while improving system diagnostics and operational visibility.

The Siemens 3RB3026-1PB0 supports both manual and automatic reset functions, allowing users to select the most appropriate reset method for their application. Automatic reset helps reduce downtime in automated systems, while manual reset provides additional safety where operator confirmation is required before restarting equipment. Typical automatic reset recovery time is approximately three minutes after an overload trip.

Built according to IEC 60947-4-1 standards, the relay offers 690V insulation voltage, 6kV impulse withstand voltage, IP20 protection, and reliable operation across ambient temperatures ranging from -25°C to +60°C. Its rugged construction and proven Siemens engineering make it suitable for manufacturing facilities, HVAC installations, water treatment plants, packaging machinery, and industrial automation projects.

At SBsmart.in, we supply genuine Siemens industrial automation and motor protection products trusted by OEMs, panel builders, electrical contractors, and maintenance professionals across India. The Siemens 3RB3026-1PB0 Electronic Overload Relay delivers dependable motor protection, enhanced equipment safety, and long-term operational reliability.