System Sensor Drywall Dust Problems with Duct Smoke Detectors

1 2011 FIELD BULLETIN Drywall Dust Problems with Duct Smoke Detectors in OEM Unitary Packaged Units any unitary packaged air conditioning units are run during the drywall installation phase of any building under to accelerate the drying of joint compound the subsequent sanding of those drywall joints and resulting may compromise the sensor heads in duct smoke detectors 2D51 Sensor Head in the InnovairFlex Duct Smoke Detector models D4120 D4120W and D4S may exhibit a condition that will require cleaning of the sensing chambers on the sensor head or replacement of the head The condition is indicated at the fire alarm panel if present or on the sensor or power board the duct smoke detector the sensor LED will blink every five seconds and the power board LED will blink every five seconds avoid this condition it is recommended that the sensor heads be removed during the construction phase and replaced construction is completed and the Certificate of Occupancy is issued The sensor heads twist out for removal and in for insertion FIGURE 1 the sensing chamber on the sensor head the sensor heads are not removed during the construction phase and the sensor chamber becomes dirty causing a condition it will not always be visible on the exterior black screen on the sensor head the sensor head be cleaned with compressed air To clean the sensor head chamber follow the following step by step instructions Remove the sensor to be cleaned from the duct smoke detector housing by twisting it in a counterclockwise skip to Step 7 Remove the sensor cover by pulling outward on each of the four removal tabs that hold the cover in place Vacuum the screen carefully without removing it If further cleaning is required continue with Step 4 Remove the chamber cover screen assembly by pulling it straight out Use a vacuum cleaner or compressed air to remove dust and debris from the sensing chamber Reinstall the chamber cover screen assembly by sliding the edge over the sensing chamber Turn until it is Replace the cover using the holes for the LEDs for alignment and then gently push it until it locks into place Reinstall the sensor in the duct smoke detector housing by aligning it in the housing and twisting it in a in place direction Cleaning only the sensor head exterior black screening will not remove any drywall dust in the sensing Should the duct smoke detector remain in a condition after cleaning then it may require the replacement of the sensor head The replacement sensor head is model 2D51 Ohio Avenue St Charles Illinois 60174 Phone 800 SENSOR2 Fax 630 377 6583 http www systemsensor com