CT operated heavy duty bimetal-relay-3UC5030-5J

Product Description

CT Operated Heavy Duty Bimetal Relay – 3UC5030-5J

The Siemens 3UC5030-5J is a CT-operated heavy-duty bimetal overload relay designed for reliable protection of electrical motors under heavy starting and long acceleration conditions. It belongs to the Siemens 3UC5 series, which is specifically engineered for applications where motors draw high inrush current or require extended starting time.

This relay works on the current transformer (CT) operated bimetal principle, where motor current is sensed through CTs and converted into proportional heating of the bimetal elements. In case of overload, phase loss, or unbalanced current, the bimetal strips bend and operate the tripping mechanism, disconnecting the motor to prevent damage.

The 3UC5030-5J is particularly suitable for heavy-duty industrial motors, providing Class 30 tripping characteristics, which allow longer starting durations compared to standard thermal relays. It ensures reliable protection in demanding applications such as crushers, compressors, conveyors, and large pumps.

🔹 Key Features

• Siemens CT-operated heavy-duty bimetal relay
• Model: 3UC5030-5J
• Part of 3UC5 overload relay series
• Designed for heavy starting applications
• CT-operated sensing for higher current ranges
• Class 30 tripping characteristic
• Protection against overload, phase loss, and unbalance
• Suitable for long motor starting time applications
• High accuracy and thermal stability
• Robust industrial-grade construction
• Compatible with Siemens contactor systems
• Easy integration in motor control circuits
• Reliable motor protection in harsh environments