Graco Uni-Drum Instructions Manual page 30

Operation
a. Turn the knob clockwise to increase air
pressure or counterclockwise to decrease air
pressure. See F
b. Check the air gauge to verify the air pressure
setting.
12. Repeat step 29 to adjust the air regulator for the
PUMP NO. 2 REGULATOR Control Knob (AE).
Adjusting the RAM UP and RAM DOWN Air
Regulators
13. At the Pneumatic Logic Panel (G) (see F
page 13), open the hinged cover.
14. Set the RAM POSITION Switch (AG) to RAISE and
push the RAM UP Pushbutton (AF). Verify that the
Follower Plate (D) raises at the desired speed. If
not, perform the following steps:
a. Adjust the RAM UP Air Regulator (AJ). Turn the
knob clockwise to increase the amount of air
pressure. Check the air gauge to verify that air
pressure was increased. See F
pressure factory setting is 50 psi, and it is not
recommended to exceed 80 psi.
b. Verify that the R3 Regulator (AL) is set to 5 to
10 psi (0.035 to 0.07 MPa, 0.35 to 0.7 bar).
Do not set the R3 Regulator higher than 5 to 10 psi
(0.035 to 0.07 MPa, 0.35 to 0.7 bar). Setting the
R3 Regulator pressure higher than recommended
can cause the Follower Plate (D) to drop and result
in operator injury.
Failure to adjust the Regulator R3 properly can cause
the platen to exit the drum at a high rate of speed,
risking damage to the equipment.
c. Repeat step 32.a until the ram raises at the
desired speed.
15. Set the RAM POSITION Switch (AG) to DOWN
while observing the air gauge inside the panel.
30
. 5 on page 14.
IG
. 4 on
IG
. 5. The air
IG
NOTICE
16. Adjust the RAM DOWN Air Regulator (AK) to 50 psi
(0.34 MPa, 3.4 bar) as follows (see F
a. Turn the knob clockwise to increase air
pressure or counterclockwise to decrease air
pressure.
b. Check the air gauge to verify the air pressure
setting. The air pressure factory setting is 50
psi, and it is not recommended to exceed 80
psi.
17. Close and secure the hinged cover.
Preventing Pump Cavitation
NOTE: Cavitation occurs when the Pump cylinder did
not fully load with material on the upstroke, and a cavity
forms in the material after the Pump changes to the
downstroke. Perform step 36 when there is Pump
cavitation. If cavitation is not occurring, omit step 36 and
proceed to step 37.
18. To prevent cavitation from occurring, perform the
following steps:
a. Press the PRIME PUMP Pushbutton to prime
the Pumps and fill the material passages.
b. Verify that the PUMP READY Light turns on.
c. Lower the air motor air pressure until cavitation
stops.
d. Increase the ram down pressure.
Adjusting the Empty/Low Limit Switches
NOTE: When the low limit switch is activated, the
Pumps are normally turned off automatically by a
customer-supplied control, and a second set of Pumps
begin pumping.
19. Adjust the low limit switch as follows:
a. At the Junction Box Panel (H) (F
RAM POSITION Switch (AG) to LOWER,
allowing the Follower Plate to activate the low
limit switch.
. 5):
IG
. 6), set the
IG
309028ZAT