Graco B Series Instructions-Parts List Manual page 12

1
Type of Problem
Dlagnoslng
clrcult board
indlcator lamps.
The normal
condition is red lamp on,
telling pump to run.
clear lamp
on when board is
Follow
Pressure
Rellef Pro-
gun from hose. Remove
cedure Warning.
Remove
pressure control cover and
check for faulty condRion of
circuit board lamps.
Condltlon A
Both lamps on; pump
won't operate and motor
is notrunning
What to Check
I
What to Do
I f check is OK, go to the next check
1. Check leads from bridge
308)
to motor to
be sure they are securey
I
fastened and
1.
properly maied.
2. CheckGlandG2connectionsbetweencir-
tions and terminals. See page 32.
or loose terminals.
3. 3. Check for loose motor brush lead connec-
cuitboard (72)and bridge(308)fordamage
2.
4. CheckbrushlengthwhichshouldbelOmm
minimum. See page 32.
NOTE
The brushes do not wear at the
samerateonbothsidesofthemotor.Check
4.
both brushes.
5. Check for broken or misali ned motor
brushsprings.Rolledportiono?springmust
rest squarely on top of brush. See page 32.
6. Check motor brushes for binding in brush 6.
holders. See page 32.
5.
7.
Checkmotorarmaturecommutatorforburn
spots,gougesandextremeroughness.Re-
7.
move motor cover and brush inspection
8.
plates to check. See page 32.
8.
Check motor armature for shorts using ar-
maturetester(growler)orperformspintest.
See page 17.
9.
Check bridge (308) by substituting with a
page18or21.
good bridgeor performing bridgetest. See
CAUTION:
Do not perform this check until ar-
mature is determined to be good. A bad ar-
mature will immediately burn
out
a good
bridge.
9.
I f
check is not OK, refer to this column
leads. Be sure male terminal blades are
Replace any loose terminals and crimp to
straight and firmly connected
to
mating
Dart.
Cleancircuitboardmaleterminals.Replace
loose or damaged terminals. Securely r e
Tightenteflinalscrews.Replacebrushesii
connect leads.
leads are damaged. See page 32.
Replace brushes. See page 32.
Replace spring if broken. Realign spring
with brush. See page
3 2 .
Clean brush holders. Remove carbon with
Smallcleanin brush.Alignbrushleadswith
slot in brush
1
older to assure free vertical
brush movement.
Remove motor and have motor shop resur-
face commutator if possible. See page 30.
Replace motor. See page
30.
Replace bridge. See page 21.
.
swmn
12 307-689