Manual 2100-695C
Page
51 of 56
8612-061 Dust (Particulate) Sensor Control Board
8612-061 Control Board Output Signal Not Responsive
to Dust
1. With a voltmeter, verify 24VAC present across
24VAC pin terminals.
A. If 24VAC is not present, trace back wires to
source.
2. Inspect and re-seat the dust sensor communication
cable.
A. Carefully remove the dust sensor
communication cable from the dust sensor
connector on the dust sensor alarm board and
the dust sensor.
B. Inspect communication cable for the following:
i. Wires pulled out of the connectors.
ii. Scars in insulation exposing bare wire.
C. If communication cable is damaged:
i. Replace communication cable.
D. If communication cable is not damaged:
i. Carefully reconnect the dust sensor
communication cable to the dust sensor
connector on the dust sensor alarm board
and the dust sensor.
FIGURE 65
8612-061 Dust Sensor Alarm Board
3. With a voltmeter, measure voltage between the
following terminals:
A. Component U1 pin 2 and terminal block pin 4
(see Figure 66).
i. Should read 12VAC
B. Component U1 pin 3 and terminal block pin 4
(see Figure 66).
i. Should read 24VAC
C. If voltage readings are correct:
i. Replace 8301-073 dust sensor.
D. If voltage readings are not correct:
i. Replace 8612-061 dust sensor alarm
board.
