Watlow Series 945, 1/4 DIN Microprocessor-BasedAuto-tuning Control - Manual (Page 31)

Appendix WATLOW Series 945 User's Manual
31
Noise Guidelines
Line Filtering Configurations For Controls
These three diagrams show 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
at ground potential. This prevents ground loops and maintains filter effectiveness.
1
1
Line
Load
2
2 1
1 NOTE:
Keep filters 12" (305
mm) or less from the
control. Minimize the
line distance where
noise can be reintro-
duced to the control.
Figure 37 -
Differential Mode
Filter Wiring
2 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.
Figure 38 -
Common Mode Filter
Wiring
Figure 39 -
Combination
Differential/Common
Mode Filter Wiring