Graco ULTRA 500 Instructions-Parts List Manual page 16

OW OUTPUT
iO0UTPuT
dotor runs and pump stroke
1. Check for worn spray tip.
2.
Check to see that pump does not continue
to stroke when gun trigger is released. Plug
in and turn on sprayer. Prime with paint.
Trigger gun momentarily, then release and
engage safety latch. Relieve pressure, turn
off and unplug sprayer.
3. Check electrical supply with volt meter.
Meter should read 105 to 125 VAC.
4. Check extension cord size and length; must
be at least 12 gauge wire and no longer thar
150 ft (15.2 mi.
5. Check G1 and G2 leads from bridge (308) to
circuit board
1 2 3 )
for damage or loose wires
or connectors. Refer to page
2 5 .
E.
Check stall pressure. Refer to Calibration
Procedure on page
27.
7. Check bridge (308)
+
and
-
leads and ter-
minals to motor. lnsmct wirina insulation
and terminals for signs of ovehating. See
page
20.
8. Check for loose motor brush leads and ter-
minals. See page
22.
be 112" minimum. See page
2 2 .
9. Check for worn motor brushes which should
10.Check for broken and misaligned motor
brush springs. Rolled pbrtion of spring must
rest squarely on top of brush.
holders. See page
2 2 .
11.Check motor brushes for'binding in brush
12.Check circuit board (23) by Substituting with
a good circuit board. See page
25.
13.Check motor armature for shorts by using
a1
armature tester (growler)
o r
perform spin
t e s t .
See page
20.
:
14.Check bridge
1 3 0 8 1
by substituting with a
good bridge or by performing the bridge
test.
See page
20.
CAUTION: Do not perform this check until
armature is determined to be good. A bad
armature will immediately bum out a good
bridge.
'
I
I. Check paint supply.
2. Check for clogged intake strainer.
3. Check for loose suction tube or fittings. See
page 28.
1. Follow Preasure Relief Procedure Wem-
Ing then replace tip. See your separate gun
o r tip manual.
2.
Service pump.
See
manual
307-793.
3. Reset building circuit breaker; replace
building fuse. Repair electrical outlet or
try
another outlet.
a.
Replace with a correct, grounded extension
cord.
5.
Clean circuit board male terminals. Replace
loose or defective lead terminals. Securely
reconnect lead terminals to board.
5.
Calibrate pressure control. See page
2?.
1. Be sure male terminal blades are centered
and firmly connected to female terminals.
ing. Securely reconnect wires to bridge.
Replace any loose terminal or damaged wir-
8. lighten terminal screws. Replace brushes if
leads are damaged. See page
22.
3. Replace brushes. See page
22.
10.Replace spring if broken. Realign spring with
brush. See page
2 ' 2 ,
11.Clean brush holders, remove carbon dust
with small cleaning brush. Align brush lead
with slot in brush holder to assure free vef-
tical brush movement.
12.Replace circuit board. See page
25.
13.Replace motor. See page 30.
14.Replace bridge. See page 24.
1. Refill and reprime pump.
2. Remove and clean, then reinstall.
3 . lighten; use thread sealant or sealing tape
on threads if necessary.
Troubleshooting continued on nextpage