Fire-Lite ACM-8RF Control Relay Module - Manual (Page 14)

2. Installation Wiring the EIA-485 Terminal Blocks
14
ACM-8RF PN 50362:C 03/21/01
EIA-485 Shield Not in Conduit
When the EIA-485 wiring is not in conduit, terminate the shield at the outside
of the FACP cabinet. Do not allow the shield to enter or even touch the cabinet
housing the ACM-8RFs. Between ACM-8RFs, wire-nut multiple shields
together outside of the respective enclosures. Ensure that the shield does not
touch earth ground at any junction points.
Figure 6 Terminating the Shield with No Conduit
EIA-485 - TB2 Terminals
Wire as shown below:
Note: Leave a 120 ohm ELR installed across the EIA-485 Out terminals at the last
ACM-8RF on the circuit (see below). All other ACM-8RFs should not have a resistor
installed.
Figure 7 EIA-485 Terminal Block - TB2
Multiple wiring of EIA-485 circuits
Figure 8 Wiring Multiple ACM-8RFs - EIA-485
1 IN (+ )
4 IN (– )
T B 2
3 O U T (– )
2 O U T (+ )
A
C
M8
R
F
-t
e
rm2
.c
d
r
1 IN (+ )
4 IN (–)
T B 2
3 O U T (– )
2 O U T (+ )
A
C
M8R
F
-T
B
2
.c
dr
T B 2
2
3
4
1
T B 2
2
3
4
1
E IA -4 8 5 (– )
E IA -4 8 5 (+ )
Host FACP
First ACM-8RF -- -- -- -- -- -- Last ACM-8RF
A
C
M8R
F
-mu
lt
.c
dr