Graco ULTRA 500 231-032 Instructions-Parts List Manual page 31

6. Plug in the sprayer.
7. Turn the pressure control knob (B) to the minimum
setting (fully counterclockwise), and turn the sprayer
ON. THE DISPLACEMENT PUMP SHOULD NOT
CYCLE
If it does cycle , remove the plug (15) from the
bottom of the pressure control. Insert a 3/8 in. nut
driver through the opening, and unscrew the
pressure adjustment nut (T) just until the sprayer
stops running.
Adjust the Overpressurization Switch
8. With the spray gun triggered, slowly turn the pres-
sure control knob clockwise just until the sprayer
starts. Prime the pump and hose.
9. Slowly turn the pressure control knob to the maxi-
mum setting. While watching the red light on the cir-
cuit board and the pressure gauge, turn the nut (T)
slowly to increase pressure until the red light goes
out and the gauge reads between 3400 –3800 psi
(238 – 266 bar).
If the red light does not go out by 3800 psi
(266 bar), loosen the nut (P) and adjust the stud
(Q) until the light goes out.
If the red light goes out before 3400 psi (238
bar), loosen the nut (P) and adjust the stud (Q)
until the light goes out between 3400 – 3800 psi
(238 – 266 bar).
10. Tighten the nut (P) if it was loosened in Step 9.
11. Trigger the gun to relieve pressure. Release the trig-
ger and engage the safety latch. Repeat Step 9 to
verify your results.
P
Q
72
INSERT WRENCH HERE
TO ADJUST NUT (T)
Fig 31–1
PRESSURE CONTROL ADJUSTMENT
Ç Ç Ç
Ç Ç Ç
B
É É É Ç Ç Ç É É É É É É É É É É É É
É É É
15
12. Install the pressure control cover.
Maximum Working Pressure Adjustment
13. Turn the sprayer OFF. Disengage the gun safety
latch. Trigger the gun into a grounded waste contain-
er until pressure is relieved. Engage the gun safety
latch.
14. Use the 3/8 in. nut driver to turn the pressure adjust-
ment nut (T) counterclockwise one full turn.
15. With the pressure control knob at the minimum set-
ting, turn the sprayer ON.
16. Slowly turn the pressure control knob (B) clockwise
to the maximum setting and hold it there. Use a 3/8
in. nut driver or socket wrench to slowly turn the pres-
sure adjustment nut (T) clockwise until the gauge
reads EXACTLY 2750 psi (195 bar).
17. Turn the pressure control knob to the minimum set-
ting. Release the gun safety latch and trigger the gun
into a grounded waste container until pressure is re-
lieved. Engage the gun safety latch. Slowly increase
the pressure to verify that the maximum working
pressure is set at 2750 psi (195 bar).
CAUTION
To prevent pump corrosion, flush the water out of the
pump, hose and gun with mineral spirits. Be sure to
close the drain valve, first. Use the lowest pressure
necessary to flush. Relieve pressure. Leave the
mineral spirits in the pump to protect it until you are
ready to spray again.
18. Install the plug (15) in the bottom of the pressure con-
trol. Remove the gauge assembly and reinstall the
plug. Flush out the water with mineral spirits.
É É
É É É É É É
31
307–758