Solenoid Troubleshooting - Graco ProMix Auto Service Parts

Solenoid Troubleshooting

Refer to the Pneumatic Diagram, page 27.
If the dispense, purge, or dump valves are not turning on or off correctly, it could be caused by one of the following.
Cause
1.
Air regulator pressure set too
high or too low.
2.
Air or electrical lines damaged
or connections loose.
3.
Solenoid failure
Dump B
Dump A
Purge
Solvent
Purge Air
Dispense B
Dispense A
F . 6
IG
4.
Solenoid, cable, or fluid panel
control board failure.
311189C
Check air pressure. 80 psi (550 kPa, 5.5 bar) is commonly used. Do not go
below 75 psi (517 kPa, 5.2 bar) or above 100 psi (0.7 MPa, 7 bar),
Visually inspect air and electrical lines for kinks, damage, or loose connec-
tions. Service as needed.
Manually operate the valves by removing the Fluid Panel cover and pressing
and releasing solenoid valve override buttons. F
operate when solenoid override is activated.
Use the control board diagnostics to check the signals (page 14). If signals
do not occur correctly, go to Cause 4.
Valves should snap open and shut quickly. If the valves actuate slowly, it
could be caused by:
• Air pressure to the valve actuators is too low. See Cause 1.
• Solenoid is clogged. Make sure air supply has 5 micron filter installed.
• Something is restricting the solenoid or tubing. Check for air output from
air line for corresponding solenoid when valve is actuated. Clear restric-
tion.
• Packings on the mix manifold dispense valves are too tight. Torque
should be 25 in-lbs (2.8 N•m). (Wall Mount Fluid Panel only.)
• Dispense Valve Travel Adjustment (Wall Mount Fluid Panel only) is
turned in too far. See ProMix™ Auto Operation manual for settings.
• Fluid pressure is high and air pressure is low.
Check voltage level to solenoid by pulling solenoid connector and checking
voltage between pins.
If voltage is 9-15 VDC, the solenoid is damaged. Replace solenoid or correct
electrical line problem.
If there is no voltage, replace the board.
Check circuit board LEDs.
Solenoid Troubleshooting
Solution
. 6. Fluid valves should
IG
13