52
Donaldson Company, Inc. © 1995
TROUBLE
POSSIBLE CAUSE
REMEDY
7.0 Troubleshooting Guide
1. Improper wiring.
2. Defective solenoids.
3. Timer board not powered.
4. Possible defective timer
board.
1. Check all wiring between
the
∆
P Control and timer
board and between the
timer board and solenoid
valve coils.
2. Check all solenoid valve
coils.
3. Check the Power On LED
on the timer board. If not
illuminated, check the
supply voltage to the timer
board with multimeter.
Check the fuse on the timer
board. Replace with identi-
cal fuse if necessary.
4. If LED is illuminated,
observe the output LEDs.
Install a temporary jumper
across the Pressure Switch
terminals. Output LEDs
should flash in sequence.
Check output using an
analog multimeter set to
150 VAC range. Measure
from SOL COM to a
solenoid output. The meter
needle will deflect if voltage
is present when LED
flashes for that output.
Replace the board if either
the LEDs do not flash or no
voltage is present at the
output terminals during
flash.
K. Control CLEANING
light on, but no pulse
cleaning occurs.