Fire-Lite LED-10 Series Remote Fire Annunciator - Manual (Page 21)

21
Document 50400 Rev B 10/27/97 P/N 50400:B
When the EIA-485 shield is in full conduit: The EIA-485 loop allows the FACP to
communicate with the annunciator(s). The shield for the EIA-485 loop must be
connected to earth ground at the FACP, but must be left floating (no connection) at
the annunciator if it is the first or only device on the EIA-485 loop. If a second
annunciator is connected, the shield leaving the first annunciator must be left
floating. The shield entering the second annunciator must be connected to the
Earth Ground Terminal (TB1- 6 & 7) on the second annunciator. If additional
annunciators are connected, the shield leaving each annunciator must be left
floating and the shield entering the following unit must be connected to the Earth
Ground Terminal (TB1 - 6 & 7) on the annunciator.
Caution! Do not allow the floating (no connection) end of the shield to contact the
conduit. The floating end should be insulated from earth ground.
Notes:
1) Power-limited 24 VDC regulated power may be run in the same conduit as the EIA-485 wiring.
2) Twisted, shielded wire is recommended for the EIA-485 communications loop.
3) Each LED-10 Series Annunciator's electrical backbox is connected to earth ground via the
conduit.
4) Shield is connected to the FACP cabinet (earth ground) leaving the FACP.
TB2-1 (+) EIA-485
TB2-2 (-) EIA-485
TB1-6 Earth Ground
(IN)
Connect the shield drain wire to the Earth
Ground Terminal on the annunciator.
LED-10 Series Box
LED-10
Series
Shield Drain Wire
Series Series Series