Model SG-100 Plasma Spray Gun
Operator’s
Manual
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Issued: 12/11
Page
41
Section 5
Maintenance
Inspect labels on this unit every six months for legibility. Maintain all
precautionary labels in a clearly readable state and replace when
necessary. See parts list for label part numbers.
5.1 Plasma-arc Starting Problems
There are several possible causes throughout a plasma system that could
cause plasma-arc starting problems. To help prevent these problems,
inspect and clean anodes, cathodes, housings, and other metallic
components, when maintenance is performed on guns. Mineral deposits
and corrosion from poor quality water can inhibit arc starting. Oxidation
of the electrodes (anodes and cathodes), which is usually the result of gas
supply leaks or contaminated gases, will affect the ability of the RF to
initiate the plasma. It is necessary to keep plasma-gas distribution systems
free of leaks. This is best accomplished through scheduled inspections,
leak checks, and maintenance. Generally, plasma gases should contain
less than 50 ppm Oxygen. For a more comprehensive list of possible
plasma-arc starting problems caused by other factors, see Service Bulletin
4.3.2.
5.2 Anode Removal and Maintenance
The anode is one of the SG-100 gun’s most critical parts. Anode life is
affected by unit operating conditions and regular maintenance. Remove,
clean, and inspect the anode after each use, and replace as necessary until
a regular maintenance and replacement schedule for the spray parameters
used becomes apparent. Completely disassemble and clean the gun daily
when the gun is used on a production basis.
See Figures 5-1, 5-2, 5-3, and 5-4, and remove anode as follows:
1. Remove two socket head cap screws (item 12) from powder tube
(item 9). Pull powder tube from gun body.