Product Overview
• Bulletin Number: 817S
• Model: PTC-48
• Type: Thermistor Monitoring Relay
• Main Functions: Used to monitor the temperature of motor coils (via built-in PTC thermistors) to prevent condensation damage caused by high-humidity environments. The device supports resetting of alarm status (via external contacts or an internal button), a fault simulation test button, and LED status indicators.
• Applicable Scenarios: Specifically designed for three-phase AC motors controlled by full-voltage starters. Not suitable for drying wet motors or applications involving reduced-voltage starters, multi-speed starters, synchronous motors, or power factor correction capacitors (consult Rockwell Automation for such cases).
• Key Features:
◦ Self-powered design, eliminating the need for an external power supply.
◦ Supports latching functionality to maintain the relay output state.
◦ Supports suppression functionality to prevent false operations.
◦ LED indicators display alarm and output relay status.
Power Specifications
• Power Code: 48 (based on Cat No. Explanation)
• Input Voltage: 24/48V AC/DC (Alternating Current/Direct Current)
Input/Monitoring Specifications
• Monitoring Type: PTC thermistor temperature monitoring.
• Response Mechanism:
◦ When the measured value (temperature) exceeds the set threshold, the relay triggers an alarm.
◦ Supports latching functionality: When enabled, the relay output state can be maintained; when disabled, the relay releases when the measured value returns to normal or when power is interrupted.
◦ Supports suppression functionality: Prevents relay operation from being triggered unnecessarily.
• Test Function: Built-in test button to simulate fault conditions for verifying device functionality.
• Alarm Indication: Alarm status is displayed via LED indicators (e.g., a flashing red LED indicates a fault).
• Reset Mechanism: Alarm status can be reset via external contacts or an internal button.
The Bulletin 817S-PTC-48 is a compact thermistor monitoring relay specifically designed for motor temperature protection, powered by 24/48V AC/DC. Its core advantages include self-powering, flexible functional settings (such as latching and suppression), and an easy-to-integrate wiring design.