Graco 190ES 309063F Repair Manual page 10

LOW OR FLUCTUATING OUTPUT
TYPE OF PROBLEM
Low Output
10
309063
Troubleshooting
WHAT TO CHECK
If check is OK, go to next check
1. For worn spray tip.
2. Verify pump does not continue to stroke when
gun trigger is released.
3. Filter clogged (If optional filter is installed).
4. Prime valve leaking.
5. Suction hose connections.
6. Electrical supply with volt meter.
Meter must read:
210--255 Vac for 220--240 Vac models.
85--130 Vac for 100--120 Vac models. Low volt-
ages reduce sprayer performance.
7. Extension cord size and length; must be at least
12 gauge wire and no longer than 300 ft. Longer
cord lengths reduce sprayer performance.
8. Leads from motor to pressure control circuit
board (35) for damaged or loose wires or con-
nectors. Inspect wiring insulation and terminals
for signs of overheating.
9. For loose motor brush leads and terminals. See
page 12.
10.For worn motor brushes which must be 1/4 in. (6
mm) minimum. See page 12.
11. For broken or missing motor brush caps.
12.Motor brushes for binding in brush holders. See
page 12.
13.Low stall pressure.
14.Motor armature for shorts by using an armature
tester (growler) or perform spin test. See page
12.
WHAT TO DO
When check is not OK refer to this column
1. Follow Pressure Relief Procedure Warn-
ing, then replace tip. See your separate
gun or tip manual.
2. Service pump. See page 26.
3. Relieve pressure. Check and clean filter.
4. Relieve pressure. Repair prime valve.
5. Tighten any loose connections.
6. Reset building circuit breaker; replace
building fuse. Repair electrical outlet or try
another outlet.
7. Replace with a correct, grounded exten-
sion cord.
8. Be sure male terminal blades are centered
and firmly connected to female terminals.
Replace any loose terminal or damaged
wiring. Securely reconnect terminals.
9. Tighten terminal screws. Replace brushes
if leads are damaged. See page 12.
10. Replace brushes. See page 12.
11. Replace brushcap if broken. Realign spring
with brush. See page 12.
12.Clean brush holders, remove carbon dust
with small cleaning brush. Align brush lead
with slot in brush holder to assure free verti-
cal brush movement.
13. Do either or both:
a. Turn pressure control knob fully
clockwise. Make sure pressure
control knob is properly installed to
allow full clockwise position.
b. Try a new transducer.
14.Replace motor. See page 25.