Wiring Instructions - Mircom RAX-LCD Installation And Wiring Manual

3.0

Wiring Instructions

The RS-485 wiring to the RAX-
LCD Display Module is
recommended to be twisted
shielded pair as shown in the
diagram to the right. The wire
gauge may be:
• 22 AWG up to 2000 ft.
• 20 AWG up to 4000 ft.
The RS-485 wiring from the
fire alarm control panel to
the annunciator(s) must be
point-to-point from the fire
alarm panel to the first
annunciator, then to the next
annunciator, and so on. No
star wiring or T-tapping is
allowed. Each RAX-LCD
Shared Display has a 120
ohm end-of-line resistor on
its RS-485 output terminals.
This is removed on all
except the last wired
module.
The 24 VDC field wiring needs to be of an appropriate gauge for the number of annunciators
and the total wiring run length. Use the Current Drain for Battery Calculations on page 8 to
calculate the maximum current for all annunciators summed together.
RS-485
INPUT
RS-485
OUTPUT
24 VDC
INPUT
24 VDC
OUTPUT
RS-485 TERMINALS
P1 P2
MGC Network
Fire Alarm Control System
System Normal
February 21, 2018 2:24PM
MONITOR
TROUBLE
ALARM SUPV.
QUEUE
QUEUE QUEUE
QUEUE
SIGNAL ACKNOW-
GENERAL
LEDGE
SILENCE ALARM
Figure 3 Annunciator Panel Connections
+
RS-485 FROM FIRE ALARM OR PREVIOUS
ANNUNCIATOR (TWISTED SHIELDED PAIR)
-
S
+
RS-485 TO NEXT ANNUNCIATOR
(TWISTED SHIELDED PAIR)
-
S
+
24 VDC POWER FROM FIRE ALARM CONTROL
PANEL OR PREVIOUS ANNUNCIATOR
-
-
24 VDC POWER TO
NEXT ANNUNCIATOR
+
Figure 2 Wiring Diagram
ADDRESS DIP SWITCHES
24V POWER TERMINALS
SW1
FIRE SYSTEM
DRILL RESET
LAMP
TEST
3