Watlow Series 942 - Manual (Page 53)

53
WATLOW Series 942 User's Manual Appendix
Noise Guidelines
Line Filtering Configurations For Controls
These three diagrams show you filter configurations for removing input power
noise. Choose the one best suited for your system. For very dirty or critical
applications - use a microcomputer-regulated power supply or Uninterruptable
Power Supply (U.P.S.). Don't fasten common mode line filters or filters with
metal cases to metal that is at ground potential. This prevents ground loops
and maintain filter effectiveness.
Line Load
L2
L1
Ground
Co
D.M. Line Filter
Shield
Figure 42 -
Differential Mode
Filter Wiring
NOTE:
Keep filters 12" (305
mm) or less from the
control. Minimize
the line distance
where noise can be
reintroduced to the
control.
Figure 43 -
Common Mode Filter
Wiring
Line Load
L2
L1
Ground
Co
C.M. Line Filter
Shield
Figure 44 -
Combination
Differential/Common
Mode Filter Wiring
C.M. Line Filter Line Load
L2
L1
Ground
D.M. Line Filter
mov
Line
Load
NOTE:
To prevent ground
loops do not fasten
common mode line
filters or filters with
metal that is at
ground potential.
Doing so will reduce
filter effectiveness.