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The XPS provides three outputs for reverse-polarity notification appliance circuits. This section
describes basic NAC wiring from the XPS to 4100-compatible appliances.
The XPS supports both Class A and Class B NAC wiring.
Class A wiring provides a circuit path XPS in the event of a single open circuit somewhere in the
loop. Class A wiring requires that two wires are routed from the XPS to each appliance, and then
back again to the XPS.
Table 3 lists the maximum distances from the XPS to the last appliance in a Class A configuration,
depending on wire gauge and current. Use Table 3 to calculate wire distances for your application
if you are using Class A wiring.
Table 3. Class A Wiring Distances
Alarm Current
@ 24 V
Max Distance w/
18 AWG
(0.8231 mm
2
)
Max Distance
w/ 16 AWG
(1.309 mm
2
)
Max Distance w/
14 AWG
(2.081 mm
2
)
Max Distance w/
12 AWG
(3.309 mm
2
)
DC
Resistance
0.25 A
420 ft. (128 m)
667 ft. (203 m)
1,063 ft. (324 m)
1,691 ft. (515 m)
6 Ohms
0.50 A
210 ft. (64 m)
334 ft. (102 m)
532 ft. (162 m)
845 ft. (258 m)
3 Ohms
0.75 A
140 ft. (43 m)
222 ft. (68 m)
354 ft. (108 m)
564 ft. (172 m)
2 Ohms
1 A
105 ft. (32 m)
167 ft. (51 m)
266 ft. (81 m)
423 ft. (129 m)
1.5 Ohms
1.25 A
84 ft. (26 m)
133 ft. (41 m)
213 ft. (65 m)
338 ft. (103 m)
1.2 Ohms
1.50 A
70 ft. (21 m)
111 ft. (34 m)
177 ft. (54 m)
282 ft. (86 m)
1 Ohm
1.75 A
60 ft. (18 m)
95 ft. (29 m)
152 ft. (46 m)
242 ft. (74 m)
0.86 Ohm
2 A
53 ft. (16 m)
83 ft. (25 m)
133 ft. (41 m)
211 ft. (64 m)
0.75 Ohm
2.25 A
47 ft. (14 m)
74 ft. (23 m)
118 ft. (36 m)
188 ft. (57 m)
0.67 Ohm
2.50 A
42 ft. (13 m)
67 ft. (20 m)
106 ft. (32 m)
169 ft. (51 m)
0.60 Ohm
2.75 A
38 ft. (12 m)
61 ft. (19 m)
97 ft. (30 m)
154 ft. (47 m)
0.55 Ohm
3 A
35 ft. (11 m)
56 ft. (17 m)
89 ft. (27 m)
141 ft. (43 m)
0.50 Ohm
Notes:
Max Distance = distance from XPS to last appliance.
This table is calculated at 50 degrees Centigrade (120 degrees Fahrenheit). If you
are installing in locations that could be exposed to higher temperatures, refer to NEC
Table 8.
Distances are based on a 3 V drop, and take into account the worst-case panel
output voltage.
If CI wire is used instead of housing cable in a fire rated enclosure, reduce wiring
distances by 38 feet (12 m) for every 10 feet (3 m) of potential exposure.
If Wheelock appliances employing EZ Mount SNAP bases are used, reduce the wiring
distance and wiring resistance by:
12 gauge wire: 3.5 feet per appliance, 0.0125 Ohms per appliance
14 gauge wire: 2.2 feet per appliance, 0.0125 Ohms per appliance
16 gauge wire: 1.4 feet per appliance, 0.0125 Ohms per appliance
18 gauge wire: 0.9 feet per appliance, 0.0125 Ohms per appliance
Step 4. XPS Field Wiring
Overview
NAC Wiring Styles
Class A NAC
Wiring Table
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