Graco 232903 Repair Manual page 9

MOTOR IS HOT AND RUNS INTERMITTENTLY
TYPE OF PROBLEM
Motor is hot and runs intermit-
tently.
ELECTRICAL SHORT
TYPE OF PROBLEM
Building circuit breaker opens
as soon as sprayer switch is
turned on.
CAUTION
Any short in any part of the
motor power circuit will cause
the control circuit to inhibit
sprayer operation. Correctly
diagnose and repair all shorts
before checking and replac-
ing control board.
Building circuit breaker opens
as soon as sprayer is plugged
into outlet and sprayer is NOT
turned on.
Sprayer quits after sprayer op-
erates for 5 to 10 minutes.
.
Troubleshooting
WHAT TO CHECK
If check is OK, go to next check
1. Determine if sprayer was operated at high
pressure with small tips, which causes low
motor RPM and excessive heat build up.
2. Be sure ambient temperature where sprayer
is located is no more than 90
is not located in direct sun.
WHAT TO CHECK
If check is OK, go to next check
1. All electrical wiring for damaged insulation, and
all terminals for loose fit or damage. Also wires
between pressure control and motor. See page
18.
2. For missing inspection plate gasket (see page
18), bent terminal forks or other metal to metal
contact points which could cause a short.
3. Motor armature for shorts. Use an armature
tester (growler) or perform spin test. See page
10. Inspect windings for burns.
4. Motor control board (35) by performing motor
control board diagnostics on page 15. If diag-
nostics indicate, substitute with a good board.
CAUTION: Do not perform this check until mo-
tor armature is determined to be good. A bad
motor armature can burn out a good board.
1. Basic Electrical Problems on page 5.
2. ON/OFF switch (23) See page 12. Be sure
sprayer is unplugged! Disconnect wires from
switch. Check switch with ohmmeter. Reading
must be infinity with ON/OFF switch OFF, and
zero with switch ON.
3. For damaged or pinched wires in pressure con-
trol. See page 15.
1. Basic Electrical Problems on page 5.
2. Electrical supply with volt meter.
Meter must read:
210–255 Vac for 220–240 Vac models.
85–130 Vac for 100–120 Vac models.
3. Tightness of pump packing nut. Over tightening
tightens packings on rod, restricts pump action,
and damages packings.
WHAT TO DO
When check is not OK refer to this column
1. Decrease pressure setting or increase tip
size.
2. Move sprayer to shaded, cooler area if pos-
_
sible.
F and sprayer
WHAT TO DO
When check is not OK refer to this column
1. Repair or replace any damaged wiring or
terminals. Securely reconnect all wires.
2. Correct faulty conditions.
3. Replace motor. See page 18.
4. Replace with a new pressure control board
(35). See page 15.
1. Perform necessary procedures.
2. Replace ON/OFF switch. See page 12.
3. Replace damaged parts. See page 15.
1. Perform necessary procedures.
2. If voltage is too high, do not operate
sprayer until corrected.
3. Loosen packing nut. Check for leaking
around throat. Replace pump packings, if
necessary. See page 19.
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