Trane WC*150B***G Series Installation Operation & Maintenance page 37

Pre-Start
Return Air Smoke Detector
The return air smoke detector is designed to shut off the unit if smoke is sensed
in the return air stream. Sampling the airflow entering the unit at the return air
opening performs this function.
In order for the smoke detector to properly sense smoke in the return air stream,
the air velocity entering the unit must be between 500 and 4000 feet per minute.
Equipment covered in this manual will develop an airflow velocity that falls
within these limits over the entire airflow range specified in the evaporator fan
performance tables.
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WC-IOM-7 • Packaged Heat Pump