Rockwell Automation System Design for the Control of Electrical Noise - Manual (Page 69)

Publication GMC-RM001A-EN-P — July 2001
Power Distribution 7-11
Special Applications for 24V dc PSUs
This section contains information considered application specific and
does not apply to all installations.
Floating Requirement
If it is necessary to maintain a floating common, a modified filter may
be used to ground the common at HF frequencies only. Refer to the
chapter Filtering Noise for details regarding filters.
Figure 7.10
Floating Common
24V dc PSU
AC Filter
+24V 24V com
Dirty Zone
Clean Zone
Dirty Load
Clean Load
Segregation
De-coupling
capacitor
Filter