Johnson Controls A99BC-300 Temperature Sensor

The Johnson Controls A99BC-300 Temperature Sensor is a high-precision PTC Silicon Sensor engineered for demanding HVACR environments. Utilizing a Positive Temperature Coefficient element, this passive sensor provides a reference resistance of 1,035 ohms at 77?F (25?C), ensuring exceptional accuracy of 0.9?F across a broad range. This specific model features a 9-3/4 foot high temperature silicon cable, making it suitable for applications where standard PVC leads would fail. The A99BC-300 is technically identical to the A99BC-300C and is designed for seamless integration with Johnson Controls System 450, A419, and A421 electronic controllers. With a 1/4 inch stainless steel probe and a robust operating range of -40?F to 248?F, it is a reliable choice for condenser fan cycling, defrost termination sensing, and walk-in cooler monitoring. For technicians extending runs, these 22 AWG leads can be lengthened up to 800 feet using shielded cable to maintain signal integrity in high-EMI environments.

• Wide Operating Range: Rated for -40/248?F (-40/120?C), supporting both low-temp refrigeration and high-heat HVAC applications.
• Superior Thermal Durability: Equipped with a 9.75-foot silicon jacketed cable that resists degradation in high-ambient conditions.
• Factory Calibrated Precision: Delivers high-accuracy performance without the need for field calibration when paired with compatible PENN temperature controls.
• Rugged Construction: Features a moisture-resistant, stainless steel sensing bulb for long-term survival in 100% condensing humidity environments.

What is the difference between A99BC-300 and A99BC-300C?
Technically, these units are identical. The "C" suffix typically denotes a commercial packaging or updated SKU designation, but the electrical specifications and silicon cable leads are exactly the same.

Can I use this sensor with an A419 control?
Yes, the Johnson Controls A99 series is the standard sensing element for the A419 and A421 series, provided the temperature requirements of your specific application fall within the -40 to 248?F range.

How do I test if the PTC sensor is functioning correctly?
Disconnect the sensor and measure resistance across the leads. At 77?F (25?C), it should read approximately 1,035 ohms. If the resistance deviates significantly from the standard PTC resistance chart, the sensor should be replaced.

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.