Graco 231-353 Instructions-Parts List Manual page 15

TYPE OF PROBLEM
Electrical
(continued)
TYPE OF PROBLEM
Low output
Basic Problem Solving
WHAT TO CHECK
If check is OK, go to next check
5. Check motor armature commutator for burn
spots, gouges and extreme roughness. Re-
move motor cover and brush inspection plates
to check. See page 20.
6. Check motor armature for shorts using arma-
ture tester (growler) or perform motor test.
See page 18.
7. Check leads from pressure control and motor to
motor start board (47) to be sure they are se-
curely fastened and properly mated.
8. Check motor start board (47) by substituting
with a good board. See page 27.
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.
9. Check power supply cord (50). Disconnect
black and white power cord terminals; connect
volt meter to these leads. Plug in sprayer. Meter
should read 105–125VAC. Unplug sprayer.
10. Check ON/OFF switch (52). Disconnect the
motor start board (47) and switch and connect
volt meter between exposed terminal on switch
and power cord's white wire. Plug in sprayer
and turn ON. Meter should read 105–125VAC
Turn off and unplug sprayer.
11. Check motor thermal cutout switch. Connect
ohmmeter between motor's red leads. Meter
should read 1 ohm maximum.
12. Remove pressure control (64) and check mi-
croswitch operation with ohmmeter:
(1) With pressure knob at lowest setting and
stem pushed into control, readings should
be: white & black = 1 ohm max.
white & red = open.
(2) With pressure knob at highest setting,read-
ings should be: white & black = open;
white & red = 1 ohm max.
13. Check pressure transducer (29) for hardened
paint or damaged or worn components. See
page 31.
Intermediate Problem Solving
WHAT TO CHECK
If check is OK, go to next check
1. Check for worn spray tip.
2. Be sure pump does not continue to stroke
when gun trigger is released. Plug in and turn
on sprayer. Prime with paint. Trigger gun mo-
mentarily, then release and lock safety latch.
Relieve pressure, turn off and unplug sprayer.
WHAT TO DO
When check is not OK, refer to this column
5. Remove motor and have motor shop
resurface commutator if possible. See
page 26.
6. Replace motor. See page 26.
7. Replace loose terminals; crimp to leads.
Be sure male terminal blades are straight
and firmly connected to mating part.
8. Replace board. See page 27.
9. Replace power supply cord. See page
27.
10. Replace ON/OFF switch. See page 27.
11. Allow motor to cool. Correct cause of
overheating. If switch remains open after
motor cools, replace motor.
12. Replace pressure control. See page 30.
13. Replace transducer. See page 31. Thor-
ough system flushing will help extend life
of transducer.
WHAT TO DO
When check is not OK refer to this column
1. Follow Pressure Relief Procedure then
replace tip. See your separate gun or tip
manual.
2. Service pump. See page 22.