Microprocessor based overload relay - 3RB (Class 10E) - 3RB3016-1NB0

Product Description

Siemens 3RB3016-1NB0 Electronic Overload Relay – Class 10E Microprocessor-Based Motor Protection

The Siemens 3RB3016-1NB0 Electronic Overload Relay is a high-precision microprocessor-based motor protection relay from the renowned SIRIUS 3RB3 Series, designed to provide reliable protection against overload, phase failure, and phase imbalance in three-phase motors. With an adjustable current range of 0.32A to 1.25A, Class 10E tripping characteristic, and compact S00 frame size, this electronic overload relay is ideal for protecting small motors and control applications in industrial automation systems.

Unlike conventional thermal overload relays that use bimetal technology, the 3RB3016-1NB0 utilizes advanced electronic current sensing and microprocessor-controlled evaluation. This intelligent design continuously monitors motor operating conditions and thermal loading, ensuring highly accurate overload protection and improved repeatability. The result is enhanced motor reliability, reduced maintenance requirements, and improved system uptime.

The relay features a Class 10E tripping characteristic, making it particularly suitable for motors operating under normal starting conditions. Class 10E protection provides rapid response to overload situations while allowing standard motor acceleration without nuisance tripping. Typical applications include pumps, fans, compressors, conveyors, HVAC systems, packaging equipment, and other industrial machinery requiring dependable motor protection.

With an adjustable current setting range of 0.32A to 1.25A, the Siemens 3RB3016-1NB0 is designed for low-power motor protection applications. The electronic protection system accurately simulates motor thermal behavior and provides inverse-time tripping characteristics that closely match actual motor heating conditions, ensuring effective protection while minimizing unnecessary shutdowns.

A major advantage of the 3RB3016-1NB0 Motor Protection Relay is its integrated phase loss protection. The relay continuously monitors all three phases and automatically disconnects the motor when a phase failure 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 3RT1015, 3RT1016, 3RT1017, 3RT2015, 3RT2016, 3RT2017, and 3RT2018 contactors, creating a compact and efficient motor starter assembly. Durable screw-type terminals ensure secure electrical connections and reliable operation in demanding industrial environments.

For enhanced monitoring and control 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, simplifying panel wiring while improving diagnostics and operational visibility.

The Siemens 3RB3016-1NB0 supports both manual and automatic reset functions, allowing users to select the most suitable recovery method for their application. Automatic reset minimizes downtime in automated systems, while manual reset provides additional safety where operator confirmation is required before restarting equipment.

Manufactured according to IEC 60947-4-1 standards, the relay offers 690V rated insulation voltage, IP20 protection, operating temperatures from -25°C to +60°C, and Siemens' proven industrial reliability. It is widely used in manufacturing plants, water treatment facilities, HVAC systems, packaging machinery, and industrial automation projects.