Temperature Thermistors

Thermistors are electronic devices which sense temperature. As the temperature increases, the resistance decreases. Thermistors are used to sense outdoor air (OAT) and coil temperature (OCT). Refer to Fig. 43 for resistance values versus temperature.

If the outdoor air or coil thermistor should fail, the control will flash the appropriate fault code. (See Table 21.)

IMPORTANT: The outdoor air thermistor and coil thermistor should be factory mounted in the final locations. Check to ensure thermistors are mounted properly per Fig. 46 and Fig. 47.

Thermistor Sensor Comparison

The control continuously monitors and compares the outdoor air temperature sensor and outdoor coil temperature sensor to ensure proper operating conditions. The comparison is:

SIn cooling if the outdoor air sensor indicates ≥ 10_F warmer than the coil sensor (or) the outdoor air sensor indicates ≥ 20_F cooler than the coil sensor, the sensors are out of range.

SIn heating if the outdoor air sensor indicates ≥ 35_F warmer than the coil sensor (or) the outdoor air sensor indicates ≥ 10_F cooler than the coil sensor, the sensors are out of range.

If the sensors are out of range, the control will flash the appropriate fault code as shown in Table 21.

OAT Thermistor must be locked in place with spherical nib end facing to- wards the front of the control box

The thermistor comparison is not performed during low ambient cooling or defrost operation.

Failed Thermistor Default Operation

Factory defaults have been provided in the event of failure of outdoor air thermistor (OAT) and/or outdoor coil thermistor (OCT).

If the OAT sensor should fail, low ambient cooling will not be allowed and the one-minute outdoor fan off delay will not occur. Defrost will be initiated based on coil temperature and time.

If the OCT sensor should fail, low ambient cooling will not be allowed. Defrost will occur at each time interval during heating operation, but will terminate after 5 minutes.

If there is a thermistor out of range error, defrost will occur at each time interval during heating operation, but will terminate after 5 minutes.

Count the number of short and long flashes to determine the appropriate flash code. Table 21 gives possible causes and actions related to each error.

OCT Thermistor must be secured tight on stub tube.

Fig. 46 – Outdoor Air Thermistor (OAT) Attachment

Fig. 47 – Outdoor Coil Thermistor (OCT) Attachment

64

Page 63 Page 65
Page 64
Image 64
Bryant R-22 service manual Outdoor Coil Thermistor OCT Attachment
Page 63 Page 65

R-22 specifications

The Bryant R-22 stands out in the landscape of residential heating and cooling systems with its combination of efficiency, durability, and modern technology. Designed primarily for homeowners seeking comfortable climate control solutions, the R-22 model delivers consistent performance throughout varying seasonal extremes.

One of the main features of the Bryant R-22 is its high energy efficiency. Rated with a SEER (Seasonal Energy Efficiency Ratio) that meets or exceeds industry standards, this air conditioning unit is designed to reduce energy consumption while providing optimal cooling. This not only helps in lowering monthly utility bills but also promotes environmentally responsible usage.

Another notable characteristic is the unit's durability. Constructed with a robust cabinet and high-quality components, the R-22 is built to withstand the rigors of daily use, with protective features that enhance its longevity. The cabinet comes with a powder-coated finish that resists corrosion and harsh weather conditions, ensuring that the unit stays functional and aesthetically pleasing for years.

The Bryant R-22 also incorporates advanced technology to improve user experience. One such innovation is the SmartSet technology, which allows homeowners to program their unit to optimize comfort levels according to their specific needs. This programmable capability enhances energy savings and ensures that the home remains at the desired temperature when residents are present.

Moreover, the unit features a Quiet Operating System that significantly reduces noise levels, making it suitable for residential areas where noise might be a concern. The design minimizes vibrations and optimizes airflow, creating a comfortable environment without disruptive sounds.

For added convenience, the Bryant R-22 is compatible with various thermostat options, including Wi-Fi-enabled models. This allows users to control their home's climate from anywhere using a smartphone app, facilitating effortless adjustments and monitoring of energy usage.

Finally, the Bryant R-22 is backed by a solid warranty, providing peace of mind for homeowners. This commitment to quality and customer satisfaction is a testament to Bryant’s dedication to producing reliable and efficient HVAC solutions. Overall, the Bryant R-22 is an exemplary choice for those looking to enhance their home comfort with the latest in HVAC technology.
Top Page Image Contents