Electrical - Graco Ultra Max II 795 Repair Manual

Electrical

Symptom: Sprayer does not run or stops running
D
Relieve pressure; page 5.
D Plug sprayer into correct voltage, grounded outlet
D Set power switch OFF for 30 seconds and then ON
again. This ensures sprayer is in normal run mode.
D Turn pressure control knob up 1/2
D View digital display
DIGITAL CONTROL BOARD
STATUS LIGHT
DISPLAY
Blank Never lights
–––– psi Blinks once and
stops
Troubleshooting
INDICATION WHAT TO DO
No power to control 1. Verify required voltage is present
board
2. Check wiring connections to control board
3. Perform continuity check on power cord and switch.
4. If steps 1 – 3 are ok, replace control board
No RUN command 1. Make sure prime valve is open and there is no pres-
to control board.
Potentiometer or
transducer problem
2. Turn pressure control knob clockwise
3. Check potentiometer connection to control board
4. Check pressure control knob alignment to potentiom-
5. Unplug potentiometer. Short out center pin of control
6. Check transducer connection
7. Disconnect and reconnect transducer plug to ensure
8. Open prime valve. Connect a known good transducer
WARNING
To avoid electrical shock or moving parts hazards
when covers are removed for troubleshooting, wait
30 seconds after unplugging power cord for stored
electricity to dissipate. Keep clear of electrical and
moving parts during troubleshooting procedures.
D If no digital display is available, use control board
status light to troubleshoot problems: Turn ON/OFF
switch OFF, remove control cover and then turn
power back ON. Observe status light.
Replace power cord or switch as needed.
sure in the system
eter shaft. Turn shaft fully clockwise and attach knob
in full ON position.
board potentiometer connector to each outer pin (one
at a time). If sprayer runs, replace potentiometer.
good connection with control board socket. Check
that transducer contacts are clean.
in place of the sprayer transducer. Set sprayer ON.
Replace transducer If sprayer runs. Replace control
board If sprayer does not run.
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