Johnson Controls A421GBF-02 Temperature Control

The Johnson Controls A421GBF-02 is a high-performance electronic temperature control designed for precise HVACR equipment automation. Operating on 24 VAC, this unit features a broad setpoint range of -40?F to 212?F, making it a versatile A419GBF-1 replacement for commercial refrigeration, boiler control, and cooling tower applications. The NEMA 1 high-impact plastic enclosure supports flexible installation via DIN rail or surface mounting. Engineers will value the intuitive front panel LCD, which provides clear status and diagnostic data. This model serves as the direct cross A421GBF-02C, ensuring seamless integration into existing systems. The included A99BB-200C temperature sensor with a 6.6-foot lead ensures accurate thermal feedback. With adjustable anti-short cycle delay and sensor offset capabilities, the A421GBF-02 optimizes compressor longevity and maintains tight temperature differentials in demanding environments.

• Precise Control: Features adjustable differential and offset settings to maintain tight temperature tolerances.
• Versatile Mounting: Designed for easy integration with standard 35mm DIN rail or flat surface mounting.
• System Protection: Integrated anti-short cycle delay protects motors and compressors from rapid cycling damage.
• Universal Cross-Reference: Serves as a modern, digital upgrade for older A419 series analog and digital controls.

Common Questions

How do I set the Penn A421 differential?
Access the programming menu via the front buttons to adjust the 'diF' parameter, allowing you to define the temperature swing before the relay toggles.

Can the A421GBF-02 control both heating and cooling?
Yes, the internal jump-start and relay configuration allow for both 'Cut-in' and 'Cut-out' logic to support either heating or cooling applications.

Is the sensor lead extendable?
The included 6.6-foot sensor can be extended up to 300 feet using shielded 22 AWG cable, provided the connections are moisture-sealed and the resistance is calibrated via the offset menu.

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.