Graco ULTRA 500 Instructions-Parts List Manual page 15

fPE OF PROBLEM
Indinion B
ontinued)
mdition C
ad lamp on, clear lamp off
nplug spra yerl
WHAT TO CHECK
I i check
I s OK,
go to next check
6.
Check motor thermal cutout switch.
Connect volt meter to TP6 female and TF3
female. Plug in and turn on sprayer. Meter
should read 105 to 125 VAC. Turn off end
unplug sprayer.
7. Check microswitch (302). Reconnect TP6
connectors. Connect volt meter to TP15
male end TP4. Meter should read 50-125
VAC.
E. Visually inspect microswitch (3021 bunon.
Adjustment stud should not depress the
zero. Manually check by depressing bunon
microswitch button when fluid pressure is
with small screwdriver; an audible click in-
dicates microswitch is in normal position.
9. Check microswitch
(302) continuity with ohm
meter. Be sure sprayer is unplugged1 Meter
should read zero ohms with no fluid pressure
in the sprayer.
10.Check all terminals for damage or l o a
fit.
Reconnect TP6 connectors.
11.Check circuit board (23) by substituting with
a
good board.
See
page
25.
1. Check circuit board 123) bv removino from
~~
25
for removal procedure.
box withoutdisconneciing wires; s & page
WARNING: Removing the circuit board
while still wired over-rides the opticel detec-
tor which could cause the sprayer to over-
pressurize, if the microswitch does not func-
tion properly. Turn the sprayer on ONLY
long enough to check lamp condition, then
shut
off
immediately.
WARNING: To reduce the risk of electric
shock, handle board by edges only1 Do not
allow any metal objects to come in contact
with the boardl
should be
on
now
-
removing the circuit
Plug in and turn on sprayer. Clear lamp
board over-rides the optical detector. Turn
off and unplug sprayer.
2. Check bourdon tube flag and detector posi-
tion. Reinstall circuit board (see page
25).
Turn pressure sening to maximum; flag
should extend less than half way into optical
detectorslot from the bonom.
VIEW OF OPTICAL DETECTOR AND FLAG
'When replacing the bare pressure control box 1301), remove the circuit breaker.
bridge, circuit board and
electrical
hardware end reinstall in the new
bare box.
WHAT
TO
DO
When check 1 s not OK n i s r
lo
thls column
~
Allow motor to cool. Correct cause of over-
heating. If switch remains open after motor
~001s. check continuity between T i 3 female
end TP10 with ohmmeter. If open, replace
motor.
loose or damaged terminals. Securely recon-
Clean microswitch male terminals. Replace
nect leads.
Microswitch is faulty. Return sprayer for
repair.
Micmswitch is faulty. Return sprayer for
repalr.
).Replace damaged terminals and reconnect
securely.
I.Replacs circuit board. See page 25.
,
Replace circuit board. See page 25.
.
Calibrate pressure control to see if that cor-
rects problem.
See
page
2 7 .
If not, replace bare pressure control box
(301)'. See page 26.
Troubleshooting continued on next page