Replacing the Potentiometer
Electrostatic discharge (ESD) potential could cause
damage to electronic pressure control. Use SprayTECH
ESD wrist strap P/N 0507958 or equivalent when working
on electronic pressure control.
1. Perform the Pressure Relief Procedure.
2. Pry off the pressure control knob cap to expose the knob
tension nut.
3. Turn the pressure control knob fully counterclockwise to
the minimum pressure setting.
4. Using a 5/16” socket, loosen the tension nut in the center
of the knob. Remove the knob.
5. Using a Phillips screwdriver, remove the four screws that
secure the electronic pressure control (EPC) assembly to
the EPC housing. Carefully remove the EPC assembly
from the housing. Gently move the assembly away from
the sprayer and allow the assembly to hang from the
housing.
6. Hold the potentiometer inside the EPC housing while
using a 1/2” thin wall socket to remove the seal nut that
secures the potentiometer to the mounting plate. Remove
the potentiometer from the EPC housing.
7. Carefully remove the potentiometer wires from their
connection point on the EPC board.
8. Insert the stem of the new potentiometer through the hole
in the mounting plate from inside the EPC housing.
Position the protruding tab on the potentiometer face into
the hole on the underside of the mounting plate (the wires
will face the open side of the EPC housing).
9. Thread the seal nut onto the threaded portion of the stem
and tighten using a 1/2” thin wall socket.
Do not over-tighten the seal nut.
10. Turn the potentiometer stem fully counterclockwise.
11. Place the pressure control knob on the potentiometer
stem with the indicator tab resting at the “minimum
pressure” tab on the mounting plate.
12. Tighten the knob tension nut using a 5/16” socket.
Do not over-tighten the knob tension nut. Over-tightening
will damage the potentiometer.
13. Connect the potentiometer wires to the EPC board. The
protruding tab on the EPC board connector will mate with
the slot on the potentiometer wires connector. The
connector on the end of the potentiometer wires and the
connector on the EPC board will mate only one way. Do
not force the connectors together.
14. Carefully place the EPC assembly over the EPC housing
taking care not to pinch any wires.
15. Install the four screws that secure the EPC assembly to
the EPC housing. Tighten securely.
CAUTION
CAUTION
EPC
Housing
Pressure Control Knob
Seal Nut
Cap
EPC
Board
EPC
Assembly
EPC
Assembly
Screw
Potentiometer
WARNING
Replacing the Sprayer ON/OFF Switch
Electrostatic discharge (ESD) potential could cause
damage to electronic pressure control. Use SprayTECH
ESD wrist strap P/N 0507958 or equivalent when working
on electronic pressure control.
1. Perform the Pressure Relief Procedure.
2. Using a Phillips screwdriver, remove the four screws that
secure the electronic pressure control (EPC) assembly to
the EPC housing. Carefully remove the EPC assembly
from the housing. Gently move the assembly away from
the sprayer and allow the assembly to hang from the
housing.
3. Locate the bottom of the sprayer ON/OFF switch inside
the EPC housing.
4. Disconnect the switch wires from the sprayer ON/OFF
switch. Remember the locations of each of the two wires
(label the wires, if necessary).
5. Depress the mounting tabs on each corner of the sprayer
ON/OFF switch inside the EPC housing and remove the
switch through the top of the housing.
6. Snap the new sprayer ON/OFF switch into the switch hole
in the EPC housing.
7. Connect the two switch wires to the new sprayer ON/OFF
switch. Make sure the wires are connected to the
corresponding terminals from which they were removed
(refer to the labels created earlier in this procedure or the
electrical schematic in the Parts List section of this
manual).
8. Carefully place the EPC assembly over the EPC housing
taking care not to pinch any wires.
9. Install the four screws that secure the EPC assembly to
the EPC housing. Tighten securely.
EPC
Housing
Sprayer ON/OFF
Switch
EPC
Board
EPC
Assembly
EPC
Assembly
Screw
WARNING
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