Potter PFC-9000 Series User Manual
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PFC-9000 • 5403535 • REV G • 9/08
CHAPTER 6 SLC LOOP DEVICES AND WIRING
SLC Loop Overview
Unlike conventional panels that utilize an initiating circuit, addressable and analog/addressable fire panels use a Signaling Line
Circuit or SLC. The recognized definition of an SLC is a circuit or path between any combination of circuit interfaces, control
units or transmitters over which multiple system input signals or output signals or both are carried.
The conventional systems are a simple pair of wires that is supervised with and end of line resistor. If the first device shorts
the pair and puts the zone in alarm, the rest of the zone is unrecognized. A SLC does not operate with a short and end of line
supervision. The panel communicates with every device, therefore the end of line supervision is not required. In addition, the
communication allows the panel to recognize additional inputs as well as communicating to outputs.
The PFC-9000 is flexible in the wiring materials and methods used. The panel will accept up to 12 AWG wire on the terminals.
In addition, the wire may be stranded or solid, twisted pair or straight lay, shielded or non-shielded so long as the total wire
resistance does not exceed 50 ohms, the line capacitance does not exceed 0.5 microfarads and the inductance does not exceed 1
micro Henry. The table below indicates the maximum loop length based on the wire size.
Analog Loop Wiring
The analog addressable loop is flexible in the variety of wiring mechanisms that can be employed as well as wiring lengths. The
wire lengths for total loop length are described in the table below.
E
Z
I
S
E
R
I
W
)
E
G
U
A
G
(
L
A
T
O
T
P
O
O
L
N
U
R
E
R
I
W
G
W
A
T
E
E
F
S
R
E
T
E
M
2
1
0
0
7
5
1
0
9
7
4
4
1
0
5
9
9
0
3
0
3
6
1
5
2
2
6
5
9
8
1
8
1
0
0
9
3
0
9
1
1
The maximum loop resistance cannot exceed 50 ohms. The line capacitance cannot exceed 0.5uF and the inductance can not
exceed 1mH. Failure to ensure these values are not exceeded will result in frequent trouble conditions and possible failure
of initiating devices.