Simplex XPS - Class a NAC Wiring Table

Step 4. XPS field wiring
The XPS provides three outputs for reverse-polarity notification appliance circuits. This section describes basic NAC wiring from the XPS to 4100-
compatible appliances.
NAC wiring styles
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.
Class A NAC wiring table
Table 2 lists the maximum distances from the XPS to the last appliance in a Class A configuration, depending on wire gauge and current. Use Table 2 to
calculate wire distances for your application if you are using Class A wiring.
Table 2: Class A wiring distances
Alarm current @ 24 V
Max. distance w/ 18
AWG (0.8231 mm²)
Max. distance w/ 16
AWG (1.309 mm²)
Max. distance w/ 14
AWG (2.081 mm²)
Max. distance w/ 12
AWG (3.309 mm²)
DC resistance
0.25 A 420 ft (128 m) 667 ft (203 m) 1,063 ft (324 m) 1,691 ft (515 m) 6 ohm
0.50 A 210 ft (64 m) 334 ft (102 m) 532 ft (162 m) 845 ft (258 m) 3 ohm
0.75 A 140 ft (43 m) 222 ft (68 m) 354 ft (108 m) 564 ft (172 m) 2 ohm
1 A 105 ft (32 m) 167 ft (51 m) 266 ft (81 m) 423 ft (129 m) 1.5 ohm
1.25 A 84 ft (26 m) 133 ft (41 m) 213 ft (65 m) 338 ft (103 m) 1.2 ohm
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
Note:
• Max. distance = distance from XPS to last appliance.
• This table is calculated at 50°C (120°F). 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 ft (12 m) for every 10 ft (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 ft for each appliance, 0.0125 ohm for each appliance
- 14 gauge wire: 2.2 ft for each appliance, 0.0125 ohm for each appliance
- 16 gauge wire: 1.4 ft for each appliance, 0.0125 ohm for each appliance
- 18 gauge wire: 0.9 ft for each appliance, 0.0125 ohm for each appliance
page 9 574-772 Rev. Q
XPS and XNAC Installation Instructions