
Table 14: Communications bus and supply terminal blocks, functions, ratings, requirements, and
cables
Terminal
block/port
label
Terminal
labels
Function, electrical ratings/requirements
Recommended cable
type
FC Bus
(port)
6-Position Modular Connector provides:
• FC Bus Communications
• FC Bus Signal References and 15 VDC
Common
• 15 VDC Power for Wireless Commissioning
• Converter or ZFR1811 Wireless Router
Wireless Commissioning
Converter retractable
cable or 24 AWG 3-pair
CAT 3 Cable <30.5 m (100
ft)
+
_
SA Bus Communications
COM
SA Bus Signal Reference and 15 VDC Common
SA BUS
SA PWR
15 VDC Supply Power for Devices on the SA
Bus (Maximum total current draw for SA Bus
is 240 mA.)
0.6 mm (22 AWG)
stranded, 3-wire
twisted, shielded cable
recommended
Note:
The + and
- wires are one
twisted pair and
the COM and SA
PWR are the second
twisted pair of wires.
SA BUS
(Port)
6-Position Modular Connector provides:
• SA Bus Communications
• SA Bus Signal References and 15 VDC
Common
• 15 VDC Power for devices on the SA Bus
and
• Wireless Commissioning Converter
24 AWG 3-pair CAT 3
Cable <30.5 m (100 ft)
HOT
24 VAC Power Supply - Hot
Supplies 20-30 VAC (Normal 24 VAC)
24~
COM
24 VAC Power Supply Common
(Isolated
from all other Common terminals on
controller)
0.8 mm to 1.5 mm (20 to
16 AWG) 2-wire
Note:
• See Table 13 to determine wire size and cable lengths for cables other than the
recommended cables.
• The SA Bus and FC Bus wiring recommendations in this table are for MS/TP bus
communications at 38.4k baud. For more information, refer to the
MS/TP Communications
Bus Technical Bulletin (LIT-12011034).
FC and SA Bus and supply power wiring guidelines
Table 14 provides information about the functions, ratings, and requirements for the NCE
communication bus and supply power terminals, and guidelines for wire sizes, cable types, and
cable lengths when wiring the communication buses and supply power.
27
NCE25 Installation Instructions