Thermal Dynamics CutMaster 75, Operating Manual

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INSTALLATION 3-10 Manual 0-2868
Art # A-02971
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Meter set to
VAC setting
Neutral
Line (Hot)
100W
Light Bulb
115 or 230VAC
WARNING
Use extreme caution. This
test uses live voltage.
115VAC: 3.0 VAC
230VAC: 1.5 VAC
V
~
V
~
VR COM A
Ground
Rod
Ground Testing
CAUTION
No other connections should be made at the ground
rod being tested. This test assumes that the 115 or
230-VAC source neutral is connected to the utility
earth ground.
2. Increasing the ground rod length beyond 20 - 30 ft (6.1
– 9.1 m) does not generally increase the effectiveness of
the ground rod. A larger diameter rod which has more
surface area may help. Sometimes keeping the soil
around the ground rod moist by continuously running
a small amount of water into it will work. Adding salt
to the soil by soaking it in salt water may also reduce
its resistance. When these methods are used, periodic
checking of the ground resistance is required to make
sure the ground is still good.
D. Routing Of Torch Leads
1. To minimize RF interference, position torch leads as
far as possible from any CNC components, drive mo-
tors, control cables, or primary power lines. If cables
have to pass over torch leads, do so at an angle. Do not
run the plasma control or other control cables in paral-
lel with the torch leads in power tracts.
2. Keep torch leads clean. Dirt and metal particles bleed
off energy, which causes difficult starting and increased
chance of RF interference.