Tweco HMC-410 - Manual (Page 42)

HMC-410
3-2 July 27, 2005
3.05 Grounding
The case of the HMC-410 control should be grounded for
personnel safety. Where grounding is mandatory under
state or local codes, it is the responsibility of the user to
comply with all applicable rules and regulations. Where
no state or local codes exist, it is recommended that the
National Electrical Code be followed.
The HMC-410 control like all solid-state equipment is
susceptible to EMI (electromagnetic interference). All
welding power sources and, in particular, TIG power
sources using high frequency arc stabilization are major
sources of EMI radiation. Care must be taken to minimize
interference through proper equipment grounding. The
chassis of the controller must be connected to a driven
ground(Figure 3-2) or a water pipe that enters the ground
not more than 10 feet from the equipment.
The ground lead should be as short as possible and a
minimum of #8 wire. This is normally accomplished by
grounding the power source chassis which is connected
to the controller chassis through the power source
interface cable.
CAUTION
Electromagnetic interference can cause the
HMC-410 to malfunction in unexpected ways.
Care should be taken when the HMC-410 is
used in motion control applications to provide
emergency shutdown in case of equipment
malfunction. Proper grounding techniques will
minimize the problem, however, an emergency
shutdown facility is still recommended.
Outside Ground Inside Ground
Art # A-04366
Figure 3-2: Grounding Rod Installation