Graco 278680 Instructions Manual page 14

Troubleshooting
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 replacing
control board.
Building circuit breaker opens as
soon as sprayer is plugged into outlet
and sprayer is NOT turned on.
Sprayer quits after sprayer operates
for 5 to 10 minutes.
14
What to Check
(if check is OK, go to next)
All electrical wiring for damaged
insulation and all terminals for loose
fit or damage. Also, wires between
pressure control and motor. See
page 20.
For missing inspection plate gasket,
see page 22, bent terminal forks or
other metal to metal contact points
which case a short.
Motor control board by performing
control board diagnostics. See page
15. If diagnostics indicate, substitute
with a good board.
NOTICE: Do not perform this check
until motor armature is determined to
be good. A bad motor armature can
burn out a good board.
Basic Electric Problems, page 10 of
Troubleshooting.
ON/OFF switch. See page 19. Be
sure sprayer is unplugged!
Disconnect wires from switch. Check
switch with ohmmeter. Reading must
be infinity with ON/OFF switch OFF,
and zero when switch is ON.
For damaged or pinched wires in
pressure control. See page 22.
Basic Electric Problems, page 10 of
Troubleshooting.
Electrical supply volt meter. Meter
must read:
• 210-255 VAC for 220-240V
models
Tightness of pump packing nut. Over
tightening tightens packings on rod,
restricts pump action, and overloads
motor.
What to Do
(When check is not OK, refer to this
column)
Repair or replace any damaged
wiring or terminals. Securely
reconnect all wires.
Correct faulty conditions.
Replace with a new pressure control
board. See page 22.
Perform necessary procedures.
Replace ON/OFF switch. See page
19.
Replace damaged parts. See page
22.
Perform necessary procedures.
If voltage is too high, do not operate
sprayer until corrected.
Loosen packing nut. Check for
leaking around throat. Replace pump
packings, if necessary. See pump
manual.
332257A