Issue
Can the old Robertshaw T99 temperature sensors be integrated to SBO?
Product Line
EcoStruxure Building Operation, TAC IA Series
Environment
SBO all versions
Cause
Retrofit job installation
Resolution
According to the RTD-DI-16 specification sheet, the T99 sensor can be integrated to SBO as follows with some limitations.
Configuration
- Use an RTD-DI-16 module with a 2 or 3 wire RTD resistive input.
- Select 1000 ohm for the Sensor class property of the RTD input object.
- Configure the Conversion Settings properties of the RTD input object near the endpoints of the temperature range to be measured using values from the T99 temperature/resistance table.
- Configure the remaining properties of the RTD input as needed.
Limitations
- Input Range. An RTD-DI-16 input configured for 1000 ohm operation is limited to an input resistance range of 500 to 2200 ohms. This will limit the temperature range that can be measured with a T99 sensor to ~115 deg. F maximum.
- Linearity Error. Depending on the range of temperatures to be measured and the needs of the application, linearity error may be significant. This can be corrected by using a script or function block program to linearize the signal based on the T99 temperature/resistance table values.
