Technical information - Johnson Controls - LIT-12014020 - RA-1270 - Airflow Measuring Station - AFMS

RA-1270 Fan Inlet Airflow and Temperature Measurement Station Product Bulletin

Johnson Controls
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Product Bulletin
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Johnson Controls RA-1270 Fan Inlet Airflow Measurement Station uses advanced thermal dispersion technology and uses either one or two sensors for each fan to reduce static pressure loss. By tracking airflow that changes through the fan, the RA-1270 uses fewer and smaller sensors to minimize pressure drop and reduce the corresponding energy penalty associated with add-on fan inlet air measurement devices. With the RA-1270 on a dual inlet fan, the airflow is only tracked on the non-pulley side of the fan where other technologies have equipment positioned in both inlets. Only one host is required for up to 16 fans with either one or two sensors per host or client. You can interface one host and up to 16 client monitor boxes through a single BACnet address.

You can use the RA-1270 on a single fan, large fan arrays, or on multiple fans installed on the same or different air handlers. Multiple fan inlet air measurement stations on up to 16 rooftop units are read from a single host interface. You can configure each sensor as an independent fan or as part of a fan array.

Optional: Configuration software and interface cables are available to simplify the setup and calibration process.

Figure 1. Fan inlet sensor cable assemblies
Callout Description
A RA-1270 Low Profile Thermal Dispersion Airflow and Temperature Sensor
Note: Sensor cable assemblies are available in 10 ft (3.05 m) or 25 ft (7.62 m) lengths. Each local host monitor box includes 25 ft (7.62 m) sensor cable assembly lengths as standard.
Figure 2. Larger view of RA-1270 Sensor
Callout Description
A RA-1270 Low Profile Thermal Dispersion Airflow and Temperature Sensor
B Sensor housing can be rotated up to 90° to position the sensor opening in-line with the direction of airflow
C Position sensor housing so the sensor opening is in-line with the direction of airflow when mounted to the fan inlet
Figure 3. RA-1270 assembly