The sampling tube should be angled at least 1 4 downward for every 12 of duct width per figure 4.
Duct smoke detector sampling tube installation.
Locate the sensor so its sampling tube is positioned in a straight length of square duct between six and ten duct widths from any bends or obstructions as shown in the diagram below.
Drill a 3 4inch hole in the duct opposite the hole already cut for the sampling tube.
The sampling tube should be angled at least 1 4 downward for every 12 of duct width per figure 4.
Ensure that the sampling tube is angled downward from the duct smoke detector to allow for moisture drainage away from the detector.
Sampling tube assembly see figure 2 the duct detectors are designed for use in ducts where the air velocities are from 300 to 4000 feet per minute.
To ensure correct operation install the superduct duct smoke detector using the following guidelines.
Move duct housing sampling tube assembly to desired location.
The end cap is needed to cre ate the proper air flow to the sensor of the duct smoke detector.
3 contents of the duct smoke detector kit 1.
Drill a 3 4inch hole in the duct opposite the hole already cut for the sampling tube.
Sampling tube connectors are equipped with set screws which allow the tubes to be mounted only in directions shown in figure 2.
See figure 12 for sensor and controller dimensions.
Sensor power board assembly and covers sensor head is factory installed 2.
Duct smoke detector a.
Ensure that the sampling tube is angled downward from the duct smoke detector to allow for moisture drainage away from the detector.
The difference in air pressure between the two tubes pulls the sampled air through the sensing chamber.
Three 10 sheet metal screws for mounting 3.
Use 4 mounting screws 4 12 x 1 2 sheet metal screws packaged in installation kit to secure the housing to the air duct.
Sampling tubes install from front and rear compatible with existing accessories able to address detector per code switches on sensor head.
Verify this by checking specifications of installation and if necessary use an alnor model 6000p velocity meter or equivalent to check the air velocity.
Air is introduced to the duct smoke detector s sensing chamber through a sampling tube that ext ends into the hvac duct and is directed back into the ventilation system through an exhaust tube.