Pressure Control Repair
309977H 17
Pressure Control Repair
Motor Control Board
Diagnostics
Note: Keep a new transducer on hand to use for test.
1. Relieve pressure; page 6.
2. Remove five screws (12) and motor cover (18).
3. Plug in power cord.
4. Observe LED operation and reference following
table:
NOTICE
Do not allow sprayer to develop fluid pressure with-
out transducer installed.
LED BLINKS SPRAYER OPERATION INDICATES WHAT TO DO
Once Sprayer runs Normal operation Do nothing
Once and stays
ON
Sprayer shuts down and
LED stays ON
Motor open circuit or bad
control board
Check motor brushes and armature.
If OK, replace motor control board.
Two times
repeatedly
Sprayer shuts down and
LED continues to blink
two times repeatedly
Run away pressure. Pres-
sure greater than 57 bar
(5.7 MPa, 830 psi).
Replace pressure transducer or
motor control board. See following
Motor Control Board procedure.
Three times
repeatedly
Sprayer shuts down and
LED continues to blink
three times repeatedly
Pressure transducer is
faulty or missing
Check transducer connection. Open
drain valve. Substitute new trans-
ducer for transducer in sprayer. If
sprayer runs, replace transducer.
Four times
repeatedly
Sprayer shuts down and
LED continues to blink
four times repeatedly
Line voltage is too high Check for voltage supply problems
Five times
repeatedly
Sprayer shuts down and
LED continues to blink
five times repeatedly
Too much current Check for locked rotor, shorted wir-
ing or motor. Repair or replace
failed parts.
Six times
repeatedly
Sprayer shuts down and
LED continues to blink six
times repeatedly
Motor thermal switch open
circuit
Check for binding in pump or drive.
Check for bad motor.