General Problem: Circuit Breaker Is Tripping - Graco MAGNUM 232738 Repair Manual

Specific Problem
Sprayer Wiring Problems
(cont.)
Specific Problem
Building circuit breaker opens
as soon as sprayer is turned on
309477F
Cause
Motor thermal overload cutoff
switch damaged.
Thermal Overload, page 7.
Terminals are damaged or
loose

General Problem: Circuit Breaker is Tripping

Cause
Sprayer electrical wiring is
pinched or insulation is
damaged.
Wires between pressure
control switch and control
board are pinched
Motor armature is shorting
Control board is damaged.
CAUTION: Do not perform
control board diagnostics until
you have determined the
armature is good. A bad motor
armature can burn out a good
motor control board.
Solution
1. Unplug sprayer electrical cord.
2. Remove motor harness from control card
3. Check for continuity between yellow leads
or motor harness.
4. If thermal relief switch is open (no continu-
ity) allow motor to cool.
5. If switch remains open after motor cools,
replace motor using Motor Kit, page 18.
6. If thermal relief switch closes after motor
cools, find correct cause of overheating.
Replace any damaged terminals. Make sure all
terminal connections are tight.
Solution
Repair or replace any damaged wiring or
terminals. Securely reconnect wires.
Check for shorts using armature tester (growler)
or perform spin test, Motor Diagnostics, page
19. If shorts are evident, replace motor using
Motor Kit, page 18.
See Control Board Diagnostics, page 19.
Replace control board if damaged using Control
Board Kit, page 18.
Advanced Troubleshooting
13