Product Overview

page 3 of 4
• Neither red nor green LED on the Makeup Air Sensor glows when the exhausting appliance is operating: check
that only one current-carrying wire to the device is passed through the hole in the Sensor. If this is correct, loop
another turn of the wire through the hole in the Sensor. The Sensor will gain sensitivity with every extra loop of
wire passing through the hole.
• The red “On” lamp on the Makeup Air Sensor blinks on and o : turn the Makeup Air Sensor adjusting screw
more to the right until it glows steadily.
• The FAD damper does not open: check the modular plug connection to the damper, and for voltage from
terminal R to C, VO to C, and AUX-IN to C on the HHSC+.
• The FAD damper does not close when the green “O ” LED is on: check the mode switch on the damper motor
and ensure it is in the Auto position, and for voltage from red to white on the FAD.
TROUBLESHOOTING
Diagram C - CAS-4 and C-Sensor, Wiring Diagram
P/N 46685800 Rev A 04/17