Johnson Controls a99bb-25c Ptc Silicon Temperature Sensor

Product Description

The JOHNSON CONTROLS a99bb-25c is a PTC (positive temperature coefficient) silicon temperature sensor designed for use with compatible Johnson Controls controllers and building automation systems. It features a PVC-jacketed cable measuring 9.75 inches in length and delivers a sensor range of -40 degrees F to 248 degrees F, covering a wide span of operating conditions. The sensor presents a resistance of 1,035 ohms at 25 degrees C (77 degrees F), a standard A99 PTC characteristic used for accurate temperature input signal conditioning. This sensor is typically installed by licensed HVAC technicians and building controls specialists working on commercial or light commercial HVAC control applications.

The a99bb-25c is suited for installation in HVAC systems where temperature sensing is required as an input to a compatible controller, such as the C450 series supply power module. It is appropriate for duct, space, or equipment-surface sensing applications where the -40 degrees F to 248 degrees F measurement range matches the process conditions. The 9.75-inch cable length provides enough reach for typical sensor mounting in duct or equipment enclosure installations without requiring additional extension wiring in standard configurations.

Key Features

• PTC silicon sensing element with standard A99 resistance curve: 1,035 ohms at 25 degrees C (77 degrees F)
• Wide temperature sensing range: -40 degrees F to 248 degrees F
• PVC-jacketed cable at 9.75 inches for flexible mounting in duct or equipment applications
• Compatible input signal type for Johnson Controls C450 series controllers
• UL listed under File E27734; FCC and Industry Canada compliant; CE marked
• 3-year manufacturer warranty

Compatibility

Designed for use with Johnson Controls C450 series supply power module controllers, including models accepting the A99 PTC temperature sensor input signal (1,035 ohms at 25 degrees C). Verify controller model compatibility before installation.

Installation Notes

Installation should be performed by a qualified HVAC technician or building controls specialist. Power down the controller and related equipment before connecting or disconnecting the sensor. Ensure the sensor cable routing avoids sharp edges, excessive heat sources, or pinch points that could damage the PVC jacket. Follow applicable local codes and the controller manufacturer wiring guidelines when terminating sensor leads.

Technical Specifications

• Sensor Type: PTC Silicon
• Sensor Range: -40 degrees F to 248 degrees F
• Resistance at 25 degrees C (77 degrees F): 1,035 ohms (A99 PTC)
• Cable Material: PVC
• Cable Length: 9.75 inches
• Certifications: UL File E27734, FCC CFR47 Part 15 Subpart B Class B, Industry Canada ICES-003 Class B, CE, RoHS, WEEE, C-Tick (N1813)
• Warranty: 3 years

Standard Information

• Brand: JOHNSON CONTROLS
• Manufacturer Part Number: a99bb-25c