Data Bus Shield Grounding Requirements When Mixing Both Ecb 24V-Powered Controllers And Ecb-Ptu Line-Powered Controllers - Distech Controls ECL/ECB-PTU Series User Manual

Figure 11: : Typical Cable-Shield Grounding Requirements for a BACnet MS/TP Data Bus Segment with
a Building Controller located in the Middle of the Data Bus
Typical BACnet Line -
Powered Controller
Data Bus Shield: Data Bus Shields: Twist
Connect to 'COM' Together and Connect
Terminal to 'COM' Terminal
Figure 12: Typical Cable-Shield Grounding Requirements for a BACnet MS/TP Data Bus Segment without
Building Controller
Typical BACnet Line -
Powered Controller
Data Bus Shields: Data Bus Shields: Twist
Connect to 'COM' Together and Connect
Terminal to 'COM' Terminal
Data Bus: Shielded Twisted Pair Cable
Data Bus Shield Grounding Requirements When Mixing Both
ECB 24V-Powered Controllers and ECB-PTU Line-Powered
Controllers
The shield on each data bus segment must be connected to the electrical system ground at
one point only, for example, at the Data Bus Master (Building Controller) if there is one, as
shown below in
the ideal point to ground the shield is in the middle of the data bus segment as shown in
15.
Figure 13: Typical Cable-Shield Grounding Requirements for a BACnet MS/TP Data Bus Segment with a Building
Controller located in the End of the Data Bus
26
Typical BACnet Line -
Bus Master (Building Controller )
Powered Controller
Data Bus Shields:
Connect to the 'S'
terminal
Typical BACnet Line -
Powered Controller
Data Bus Shields: Twist
Together and Connect
to 'COM' Terminal
Electrical
System
Ground
Figure 13 and Figure 14. On data bus segments without a Data Bus Master,
Typical BACnet Line -
Powered Controller
Typical EC-BOS Device
S + -
Data Bus Shields: Twist
Together and Connect
to 'COM' Terminal
Data Bus: Shielded Twisted Pair Cable
Electrical The shield of the data bus must be connected to
System the electrical system ground at one point only –
Ground usually at the Building Controller , when present
Typical BACnet Line - Typical BACnet Line -
Powered Controller Powered Controller
Data Bus Shields: Twist
Together and Connect
to 'COM' Terminal
The shield of the data bus must be connected to
the electrical system ground at one point only,
ideally in the middle of the data bus as shown
Typical BACnet Line -
Powered Controller
Data Bus Shield:
Connect to 'COM'
Terminal
Typical BACnet Line -
Powered Controller
Data Bus Shields:
Connect to 'COM'
Terminal
Figure
Network Guide