Preventive Maintenance
7
Nordson Corporation 1994
All Rights Reserved
108 129
Issued 3/94
Manual No. 31
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13
1.
Remove the gun from the mounting bar.
2.
Disconnect the powder feed tubing from the pump and gun and
leave the gun end in the booth.
3.
Make sure exhaust fans are running. Blow out the feed tubing,
from the pump end into the booth. NEVER blow powder back-
wards into the pump.
4.
Disassemble the gun’s powder path and blow clean with low
pressure compressed air.
5.
Wipe parts with a clean, dry cloth and replace worn parts. If
impact-fused powder has built up on contact surfaces, clean off
carefully with a wooden dowel or similiar tool. Never use sharp
objects to clean parts coming in contact with the powder stream.
Scratches in the surfaces will allow powder to build up and fuse,
clogging the gun.
NOTE:
If necessary, use a cloth dampened with isopropyl or ethyl
alcohol to clean parts. Remove O-rings before cleaning. Use alcohol
sparingly, as a last resort. DO NOT immerse guns in alcohol. DO NOT
use other solvents.
6.
Clean the spray booth as described in your booth or system
manual.
WARNING
: Before performing the following procedure, shut
off all electrical power at a disconnect switch or breaker ahead
of the power supply or master control module. Ground the
electrode before removing the gun from the mounting bar.
Wait three minutes after shutting off power supply before
removing cable from multiplier well.
Measure the resistance of the high voltage cable and gun resistor with
a megohm meter. If your readings are not in the proper range, replace
the component. The resistance of the cable and the gun resistor limit
the amperage at the gun electrode to safe levels. If this resistance
breaks down, the amperage at the electrode could increase enough to
cause electrical shock, fire, or explosion. Failure of the cable or gun
resistor will cause a loss of powder wrap and poor coating efficiency.
1.
Disconnect cable assembly from electrostatic power supply and
measure the resistance, from cable end to gun electrode.
Resistance of cable assembly should be:
332 to 456 M
, at 500 volts.
4. Preventive Maintenance
Daily
Periodically
