Graco MAGNUM 232738 Repair Manual page 12

Specific Problem
Basic electrical problems
Sprayer Wiring Problems
NOTE: Remove enclosure
mounting screws and pull
enclosure away from drive
housing. Take care not to pull
on leads from electrical cord
and power switch.
12
Cause
Motor overheated
Electrical outlet is damaged
Control board leads are
improperly fastened or
improperly mated
Motor brushes are worn.
Motor armature commutator
damaged
Motor armature shorting
Control board damaged.
CAUTION: Do not perform
control board diagnostics until
you have determined the
armature is good. A bad
armature can burn out a good
control board.
Sprayer electrical cord
damaged
Sprayer power switch damaged
Solution
Allow motor to cool for 30 minutes. Retry.
Reset building circuit breaker or replace building
fuse. Try another outlet.
Check electric supply with volt meter. Meter must
read 200-260V AC. If voltage is too high, do not
plug sprayer in until outlet is corrected.
Replace any loose terminals. Make sure all leads
and harnesses are firmly connected.
Check pressure control harness connection on
front side of drive housing.
Clean control board terminals. Securely reconnect
leads.
Check length of BOTH brushes (brushes do not
wear evenly on both sides of the motor). Brush
length must be 6.4mm (0.25 in). If brushes are
worn replace motor using Motor Kit, page 18.
Check for burn spots, gouges and extreme
roughness. Have motor shop resurface
commutator if possible, or replace motor using
Motor Kit, page 18.
Check for shorts using armature tester (growler)
or perform spin test, Motor Diagnostic, 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.
1. Unplug sprayer electrical cord.
2. Disconnect black electrical cord wire at
power switch
3. Unplug in-line connection white cord wire.
4. Plug in electrical cord
5. Test voltage between black and white
wires. Meter must read 200-260 V AC.
6. Replace electrical cord if no voltage.
1. Unplug sprayer electrical cord.
2. Disconnect black control board wire at
power switch.
3. Unplug in-line connection white cord wire.
4. Plug in electrical cord.
5. Turn power switch ON.
6. Test voltage between open terminal of
power switch and white electrical cord wire.
Meter must read 200-260 V AC.
7. Replace power switch if no voltage.
Advanced Troubleshooting
309477F