SIRIUS 3US Thermal Overload Relay for Reliable Motor Overload Protection – 3US5800-5C8K

🔹 Siemens SIRIUS 3US Thermal Overload Relay – 3US5000-5C8K (Motor Protection Relay)

🔹 Product Description

The Siemens 3US5000-5C8K is a thermal overload relay from the SIRIUS 3US series, designed for reliable protection of electric motors in low-to-medium current industrial applications. It protects motors against overload, phase failure, and overheating, ensuring safe operation and preventing damage in continuous-duty motor systems.

This model belongs to the 3US5000 frame range, typically used in compact motor starter assemblies for small industrial machinery, pumps, HVAC systems, conveyors, and automation panels. It is commonly mounted with Siemens contactors in modular control panel setups.

The relay operates on a bimetal thermal principle, where motor current flows through heater elements that generate heat. When the current exceeds the preset limit for a sustained duration, the bimetal strip bends and activates the trip mechanism, disconnecting the motor to prevent thermal damage. This provides inverse-time overload protection, meaning higher overload leads to faster tripping.

As per Siemens SIRIUS protection design (3US/3RU family behavior), the relay ensures phase-loss sensitivity and stable motor current monitoring, making it suitable for continuous industrial motor operation.

🔹 Key Features

• Genuine Siemens SIRIUS 3US series thermal overload relay
• Model: 3US5000-5C8K
• Designed for low-to-medium current motor protection
• Bimetal thermal overload protection system
• Protection against overload and phase failure
• Suitable for compact motor starter systems
• Compatible with Siemens contactor-based assemblies
• Reliable inverse-time tripping characteristic
• Phase-loss protection for improved motor safety
• Industrial-grade durability and long service life