Air Flow Sensor Operation - Carrier EACAAXCC0014 Installation And Operation Manual

How the Air Flow Sensor Works (available on specific models)
The electronic AFS was designed to provide an efficient and reliable method
of controlling the operation of the air cleaner when the dealer is unable to
wire the unit directly into the furnace blower. The electronic AFS utilizes a
thermistor that heats up to approximately 130°E The AFS then stabilizes at
this temperature and when the furnace blower turns on and air flows through
the ductwork, the same vacuum effect pulls cooler air over the hot surface.
This air movement cools down the thermistor and this cooling down effect
allows the electronic AFS to understand that the furnace blower is moving air
and the Electronic Air Cleaner must turn on to provide air cleaning.
If the air cleaner is installed in a location that is dusty and dirty, the sensor on
the AFS can become coated with dirt and lint. This coating can insulate the
AFS and keep it from operating properly. To clean the thermistor, take a
cotton swab dipped in rubbing alcohol and carefully insert it into the hole
located on the right hand side of the power pack assembly (when facing the
unit). The hole is 3/16" in diameter and is located on the front of the power
tray assembly. Carefully twirl the cotton swab between your fingers, making
sure the tip is lightly in contact with the grey disc, cleaning this coating from
thethermistor. T.E.___
Figure 1
individual to personal injury
1. Make sure the furnace blower is not operating, the rocker
is OFF and the circuit breaker is turned OFF or cord is
disconnected.
4. Locate the AFS. It is a circuit board with a small grey_q
connected to the circuit board by two(2) silver .wi'res (sir_ to
Figure 1). Carefully bend the thermistor so that it is Iocat, In the
center of the opening and approximately 1/8" from the inside edge
of the power pack assembly.
5. Reinstall the power tray assembly end access door.