Ranco 9531N400-070U Temperature Control

The Ranco 9531N400-070U is a dual-stage digital temperature controller designed for precision thermal management in HVACR applications, such as walk-in coolers and specialized refrigeration units. Operating with a 120V/240V AC input, this controller features two independent SPDT relay outputs, allowing for simultaneous heating and cooling control or multi-stage cooling configurations. Its wide temperature sensing range of -30°F to 220°F ensures versatility across various setpoints. The unit utilizes an NTC thermistor sensor for high-accuracy feedback, minimizing cycle drift and protecting compressors from short-cycling through adjustable differential settings. Built for the field, the NEMA 1 enclosure provides reliable protection for internal circuitry while the LCD display offers real-time diagnostics and easy field programming. This controller is a direct drop-in for electronic temperature control upgrades where reliable switching and clear setpoint visibility are non-negotiable for system uptime.

• Dual-Stage Control: Manages two separate loads independently, making it ideal for multi-stage refrigeration or heating/cooling integration.
• Wide Operating Range: Wide -30°F to 220°F (34°C to 104°C) scale covers high-temp and low-temp applications with a single device.
• Adjustable Differential: Fine-tune the 1°F to 30°F differential to prevent rapid cycling and extend the life of contactors and compressors.
• Universal Voltage: Field-selectable power input simplifies inventory management for contractors servicing 120V or 240V systems.
• NTC Sensor Compatibility: Includes a high-precision sensor for accurate ambient or fluid temperature monitoring.

Common Technical Questions

Can this controller be used for both heating and cooling?
Yes, each stage can be configured independently for heating or cooling modes, providing flexibility for specific equipment sequences.

How do I calibrate the sensor reading?
The interface allows for a temperature offset adjustment to align the digital display with a calibrated reference thermometer.

What happens if the sensor fails?
The unit features an error-code display and can be programmed to de-energize relays upon sensing a thermistor short or open circuit to prevent system damage.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.