Purchase now 140C Bonfiglioli Thermal Protection Sensor 140°C

Technical Description: Bonfiglioli 140C Thermal Protector

The Bonfiglioli 140C is a specialized thermal protection component designed to monitor and safeguard industrial electric motors. This sensor is calibrated to trigger at a threshold of 140°C, acting as a failsafe against winding insulation breakdown. It is an essential spare part for maintaining the safety integrity of Bonfiglioli motors operating in heavy-duty or high-temperature environments.

Functionality and Integration

Integrated directly into the motor windings during manufacture or overhaul, the 140C sensor monitors internal heat. In the event of an abnormal temperature rise—often caused by stall conditions, phase loss, or ventilation blockage—the sensor changes state. This signal is sent to the motor starter or PLC to disconnect power, preventing catastrophic failure and costly downtime.

Key Specifications

• Trigger Temperature: 140°C.
• Type: Bimetallic or Thermistor (Check specific motor series).
• Compatibility: Suitable for Bonfiglioli BN, BE, and BX motor series.
• Function: Thermal Overload Protection.
• Contact Type: Typically Normally Closed (NC).
• Standard Compliance: Meets industrial winding protection norms.

Why 140°C?

The 140°C threshold is specifically chosen for motors with Class F insulation. While Class F can withstand up to 155°C, setting the protection at 140°C provides a safety margin that ensures the motor is de-energized before the insulation reaches its critical degradation point, significantly extending the motor’s total lifecycle.

Maintenance Insights

When a motor trips via the 140C sensor, it is vital to investigate the root cause (e.g., clogged fan cover or overloaded gearbox) before resetting. Replacing a damaged sensor requires technical expertise to ensure proper contact with the winding copper.

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