28
PRESSURE CONTROL ADJUSTMENT
This procedure sets the sprayer to3000 psi (210 bar)
MAXIMUM WORKING PRESSURE and sets the
overpressurization switch (microswitch) to approxi-
mately 3600 psi (242 bar).
Perform this procedure whenever the pressure control
assembly is removed and reinstalled or replaced, or a
new circuit board is installed.
Improper adjustment can cause the sprayer to over-
pressurize and result in component rupture, fire or ex-
plosion. It may also prevent the sprayer from obtaining
the maximum working pressure, resulting in poor
sprayer performance.
NEVER try to increase the sprayer’s maximum work-
ing pressure of 3000 psi (210 bar ) by performing these
adjustments in any other way. Normal operation of the
sprayer at higher pressures may result in component
rupture, fire or explosion. To perform this adjustment,
however, the sprayer pressure must be
temporarily in-
creased above the normal working pressure.
Use a
new 50 ft (15.2 m) spray hose rated for at least
3000 psi (210 bar) MAXIMUM WORKING PRES-
SURE. A used, under–rated hose could develop a
high pressure leak or rupture.
WARNING
USE EXTREME CAUTION WHEN PERFORMING THIS ADJUSTMENT PROCEDURE
to reduce the risk of a
fluid injection injury or other serious bodily injury which can result from component rupture, electric shock, fire,
explosion, or moving parts.
NOTE:
The following tools and equipment are required
for this procedure.
3/8 in. nut driver or 3/8 in. socket wrench
1/4 in. open end wrench
7/16 in. open end wrench
0 – 5000 psi, oil–filled test gauge, Part No. 102–814
Pail of clean water
Mineral spirits
NEW 3000 psi (210 bar) high pressure spray hose,
Part No. 214–915
1. Follow the
Pressure Relief Procedure Warning
on
page 22.
2. Refer to the above list of tools and equipment needed.
Remove the plug (62a) from the top of the fluid filter
and install the fluid-filled pressure gauge. Refer to Fig
28–1. Connect the gun to the
new
test hose and con-
nect the hose to the sprayer outlet.
3. Remove the pressure control cover.
62a
Fig 28-1
4. Place the pump suction tube in a pail of clean water.
5. Be sure the gun safety latch is engaged.
NOTE:
For Steps 5 through 18, refer to Fig 29–1.
6. Plug in the sprayer.
7. Turn the pressure control knob (A) to the
minimum
setting (fully counterclockwise), and turn the sprayer
ON.
THE DISPLACEMENT PUMP SHOULD NOT
CYCLE
If it does cycle,
remove the plug (7) from the bot-
tom of the pressure control. Insert a 3/8 in. nut
driver through the opening, and unscrew the
pressure adjustment nut (D) 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 maximum
setting. While watching the red light on the circuit
board and the pressure gauge, turn the nut (D)
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 (B) and adjust the stud (C)
until the light goes out.
If the red light goes out before 3400 psi (238
bar),
loosen the nut (B) and adjust the stud (C)
until the light goes out between 3400 – 3800 psi
(238 – 266 bar).
10. Tighten the nut (B) 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.
12. Install the pressure control cover.
