307–920
SPIN TEST
Pressure Relief Procedure
To reduce the risk of serious bodily injury , including
fluid injection, injury from splashing fluid or solvent in
the eyes or on the skin, moving parts or electric shock,
always follow this procedure whenever you shut off the
sprayer, when checking or servicing any part of the
spray system, when installing, cleaning or changing
spray tips, and whenever you stop spraying.
1. Engage the gun safety latch.
2. Turn the ON/OFF switch to OFF.
3. Unplug the power supply cord.
4. Disengage the gun safety latch. Hold a metal part
of the gun firmly to the side of a grounded metal
pail, and trigger the gun to relieve pressure.
5. Engage the gun safety latch.
6. Open the pressure drain valve, having a container
ready to catch the drainage. Leave the pressure
drain valve open until you are ready to spray again.
If you suspect that the spray tip or hose is completely
clogged, or that pressure has not been fully relieved af-
ter following the steps above, wrap a rag around the tip
guard retaining nut or hose end coupling and
VERY
SLOWLY loosen the part to relieve pressure gradually,
then loosen completely. Now clear the obstruction.
WARNING
For checking armature, motor winding and brush electri-
cal continuity.
Setup
Remove the drive housing from the sprayer as described
in
DRIVE HOUSING REPLACEMENT
, Steps 1–6, page
33.
Remove the pressure control cover, the motor shield, the
fan cover (F), and the inspection covers (J).
See Fig 8.
Disconnect the two leads from the motor to the bridge
(308).
See Fig 9.
Armature Short Circuit Test
Quickly turn the motor fan by hand. If there are no shorts,
the motor will coast two or three revolutions before com-
ing to a complete stop.
If the motor does not spin freely and resists rotation, the
armature is shorted and the motor must be replaced. See
page 34.
Armature, Brushes, and Motor Wiring Open
Circuit Test (Continuity)
Connect the two black motor leads together with a test
lead.
Turn the motor fan by hand at about two revolutions per
second.
If there is uneven or no turning resistance, check the fol-
lowing and repair parts as needed. See page 23.
a) broken brush springs
b) broken brush leads
c) loose brush terminal screws
d) worn brushes
e) broken motor leads
f) loose motor lead terminals
If there is still uneven or no turning resistance, replace the
motor. See page 34.
F
J
Fig 8
Fig 9
308
303
309
23
302
Summary of Contents for 231-081
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