Secutron MR-2312-AT, Installation Manual

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MR-2312-AT Remote Annunciator Wiring and Instruction Manual
3
Wiring Instructions
The RS-485 Wiring to the MR-2312-
AT Module is recommended to be
twisted shielded pair as shown in
the diagram. 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
MR-2312-AT Annunciator Module
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 5 to calculate the
maximum current for all annunciators summed together.
Note:
All circuits are power limited and must use type FPL, FPLR, or FPLP power limited
cable.
WARNING:
Accidentally connecting any of the 24 VDC wires to the RS-485 wiring will
result in damage to the annunciator and/or to the fire alarm control panel to which it is
connected.
Total
Maximum
Current for all
Annunciators
Maximum Wiring Run to Last Annunciator
Max Loop
Resistance
18AWG 16AWG 14AWG 12AWG 0hms
Amperes ft. m ft. m ft. m ft. m Ohms
0.12 1180 360 1850 567 3000 915 4250 1296 15
0.30 470 143 750 229 1200 366 1900 579 6
0.60 235 71 375 114 600 183 850 259 3
0.90 156 47 250 76 400 122 570 174 2
1.20 118 36 185 56 300 91 425 129 1.5
1.50 94 29 150 46 240 73 343 105 1.2
1.70 78 24 125 38 200 61 285 87 1.0
+
24 VDC
OUTPUT
-
S
S
-
+
-
+
-
+
RS-485
OUTPUT
RS-485
INPUT
24 VDC
INPUT
24 VDC POWER FROM FIRE ALARM CONTROL
PANEL OR PREVIOUS ANNUNCIATOR
24 VDC POWER TO
NEXT ANNUNCIATOR
RS-485 TO NEXT ANNUNCIATOR
(TWISTED SHIELDED PAIR)
RS-485 FROM FIRE ALARM OR PREVIOUS
ANNUNCIATOR (TWISTED SHIELDED PAIR)