Shielding For External Device Wiring - Honeywell NOTIFIER NFC-50/100 Instruction Manual

Shielding for External Device Wiring

2.11 Shielding for External Device Wiring
The external data bus and external audio riser circuits must be wired using twisted pair cable. Shielded cable is optional but is recom-
mended for sites with electric machinery, electric motors, etc. to minimize the effects of electrical interference. Do not run either cable
adjacent to or in the same conduit as 120 VAC service, noisy electrical circuits that are powering mechanical bells or horns, speaker cir-
cuits, motor control circuits or SCR power circuits. External operator interface power (24VDC) may be run adjacent to or in the same
conduit as the external data bus and external audio riser circuits.
At the NFC-50/100 unit, the cable shields must be connected to the same connectors where the signals originate. If only one external
device (i.e. an NFC-RM) is used in the system, the shield in the external device must be left floating. It must not touch anything. If mul-
tiple external devices are used in the system then the shields must "pass through" (connect to the outgoing shield using wire nuts without
touching anything else). For Class A (Style Z) installations, the shield from the last external operator interface must be connected to the
same NFC-50/100 terminal that the shield originated from.
NOTE: Never use a cable shield as an enclosure's earth ground. The EIA-485 shield is for radiated noise emission protection (RFI,
EMI).Refer to the following illustrations for details on shield termination.
Class B
(Style Y)
Class A
(Style Z)
Class B
(Style Y)
Class A
(Style Z)
Notifier FirstCommand Series Manual — P/N LS10001-001NF-E:H 1/8/2018
NFC-50/100
NFC-50/100
Figure 2.29 Shielding for One External Device
NFC-50/100
External
Data Bus or
External
Audio Riser
NFC-50/100
Figure 2.30 Shielding for Multiple External Devices
External Data Bus or
External Audio Riser
External Data Bus or
External Audio Riser
"pass through"
NFC-50DA
NFC-125DA
NFC-50/100DA
"pass through"
NFC-50DA
NFC-125DA
NFC-50/100DA
External Data Bus or
External Audio Riser
NFC-RM
NFC-RPU
NFC-LOC
NFC-50DA
NFC-125DA
NFC-50/100DA
NFC-RM
NFC-RPU
NFC-LOC
NFC-50DA
NFC-125DA
NFC-50/100DA
NFC-RM
NFC-RPU
NFC-LOC
NFC-RM
NFC-RPU
NFC-LOC
Installation
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