Mircom RAM-300LCD Series, Installation And Operation Manual

Page: 9 / 16

9
4.0 Wiring
To wire the RAM-300LCD, you must first remove the dead front plate. Wire from the last RAM-
300LCD to the next RAM-300LCD and so on; then from the first RAM-300LCD to the Fire
Alarm Panel. There are only two connections to be made, one for power and the RS-485 loop.
Replace the dead front plate once all functional setup and wiring is complete.
The RS-485 Wiring to the RAM-300LCD is recommended to be Twisted Shielded Pair. The
wire gauge may be
• 22 AWG up to 2000 ft.
• 20 AWG up to 4000 ft.
The 24V DC field wiring needs to be of an appropriate gauge for the number of annunciators
and the total wiring run length. See Current Drain for Battery Calculations on page 11 and
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.
Attention:
Accidentally connecting any of the 24V DC 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.
Table 4 Maximum Wiring Run to Last Annunciator
Max for all
Annunciators
Max Loop
Resistance
18AWG 16AWG 14AWG 12AWG
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
i
!
firealarmresources.com