Siemens SIRIUS 3RB3 Electronic Overload Relays
Siemens SIRIUS 3RB3 Electronic Overload Relays feature a 0.1A to 115A seamless current range and are designed for inverse-time delayed protection of electrical loads under normal and heavy starting. The relays protect against excessive temperature rises due to overload, phase asymmetry, or phase failure. The 3RB31 electronic overload relays also allow internal ground fault detection. This fault detection feature provides protection of loads against incomplete ground faults due to damage to the insulation material, moisture, and condensed water. Siemens Sirius 3RB3 Electronic Overload Relays are suitable for operation with frequency converters and are manufactured in accordance with environmental guidelines and contain environmentally friendly and reusable materials. The devices comply with important worldwide standards and approvals.
Features
- Designed to protect three-phase motors in sinusoidal 50Hz/60Hz voltage networks
- Optimum inverse-time delayed protection of motors under normal and heavy starting conditions
- Allows easy and consistent configuration with one series of overload relays (for small to large loads)
- Insensitive to external influences, such as shock, corrosive ambient conditions, aging, and temperature fluctuations
- 0.1A to 115A seamless current range
- -25°C to +60°C temperature compensation in accordance with IEC 60947-4-1
- Provides optimum inverse-time delayed protection of loads against excessive temperature rises due to overload or phase asymmetry
- Minimizes heating of three-phase motors during phase failure
Applications
- Industrial automation motor protection
- Industrial control
- Packaging and material handling
- Heating, ventilation, and air-conditioning (HVAC) systems
- Food and beverage
- Chemicals and pharmaceuticals
System Diagram
Accessories
Published: 2025-09-23
| Updated: 2025-10-06