Amplifier Field Wiring
Overview
This section contains field wiring guidelines and illustrations for the amplifiers. These diagrams apply to both the Flex-35 and Flex-50. Wiring of optional
NAC Expansion, Class A, and Constant Supervision NAC (CSNAC) modules is also covered in this section, as well as speaker circuit wiring distances.
Since the Flex amplifiers allow self-backing operation, no wiring is required for configuring an amplifier for backup operation.
Note: TrueAlert ES speaker appliances have a maximum wire length. Refer to the Speaker Wiring Application. Guidelines in the ES Power Supply IDNAC
Card Installation Instructions, 579-1289 (for legacy EPS installations, see 579-1015 )
Note: “Applied Power” is the total amplifier power available to the speaker circuit. Applied power is consumed by speakers and wiring losses. “Actual
Power” is the speaker power available over the maximum distances designated for each wire size. Complying with the wire sizes and associated
distances specified will ensure no more than a 3dB wiring power loss to the end of the speaker circuit.
Table 1: Class A Speaker Circuit Wiring Distances for Flex Amplifiers*
Power (Watts) Distance to the Last Speaker (One Way) (Feet/Meters)VRMS
Applied Actual 12 AWG
(3.309 mm2)
14 AWG
(2.081 mm2)
16 AWG
(1.309 mm2)
18 AWG
(0.8231 mm2)
25 50 25 812 ft. (247 m) 510 ft. (155 m) 340 ft. (104 m) 200 ft. (61 m)
25 40 20 1,015 ft. (309 m) 640 ft. (195 m) 402 ft. (123 m) 252 ft. (77 m)
25 30 15 1,350 ft. (411 m) 850 ft. (259 m) 535 ft. (163 m) 337 ft. (103 m)
25 20 10 2,035 ft. (620 m) 1,250 ft. (381 m) 804 ft. (245 m) 505 ft. (154 m)
25 10 5 4,070 ft. (1,241 m) 2,600 ft. (792 m) 1,600 ft. (488 m) 1,012 ft. (308 m)
70 50 25 6,500 ft. (1,981 m) 4,096 ft. (1,248 m) 2,578 ft. (786 m) 1,620 ft. (494 m)
70 40 20 8,121 ft. (2,475 m) 5,108 ft. (1,557 m) 3,212 ft. (979 m) 2,020 ft. (616 m)
70 30 15 10,860 ft. (3,310 m) 6,800 ft. (2,073 m) 4,270 ft. (1,301 m) 2,689 ft. (820 m)
70 20 10 16,212 ft. (4,941 m) 10,190 ft. (3,106 m) 6,400 ft. (1,951 m) 4,030 ft. (1,228 m)
70 10 5 32,400 ft. (9,876 m) 20,000 ft. (6,096 m) 12,500 ft. (3,810 m) 8,000 ft. (2,438 m)
Table 2: Class B Speaker Circuit Wiring Distances for Flex Amplifiers*
Power (Watts) Distance to the Last Speaker (One Way) (Feet/Meters)VRMS
Applied Actual 12 AWG
(3.309 mm2)
14 AWG
(2.081 mm2)
16 AWG
(1.309 mm2)
18 AWG
(0.8231 mm2)
25 50 25 1,624 ft. (495 m) 1,021 ft. (311 m) 680 ft. (207 m) 400 ft. (122 m)
25 40 20 2,033 ft. (620 m) 1,279 ft. (390 m) 804 ft. (245 m) 505 ft. (154 m)
25 30 15 2,707 ft. (825 m) 1,704 ft. (519 m) 1,070 ft. (326 m) 673 ft. (205 m)
25 20 10 4,067 ft. (1,240 m) 2,558 ft. (780 m) 1,608 ft. (490 m) 1,011 ft. (308 m)
25 10 5 8,140 ft. (2,481 m) 5,120 ft. (1,561 m) 3,219 ft. (981 m) 2,024 ft. (617 m)
70 50 25 13,000 ft. (3,962 m) 8,197 ft. (2,498 m) 5,154 ft. (1,571 m) 3,241 ft. (988 m)
70 40 20 16,243 ft. (4,951 m) 10,216 ft. (3,114 m) 6,424 ft. (1,958 m) 4,040 ft. (1,231 m)
70 30 15 21,721 ft. (6,621 m) 13,602 ft. (4,146 m) 8,553 ft. (2,607 m) 5,379 ft. (1,640 m)
70 20 10 32,424 ft. (9,883 m) 20,394 ft. (6,216 m) 12,823 ft. (3,908 m) 8,065 ft. (2,458 m)
70 10 5 64,800 ft. (19,751 m) 40,000 ft. (12,192 m) 25,000 ft. (7,620 m) 16,000 ft. (4,877 m)
* Wiring distances affected by capacitance of speaker circuit wiring if using CSNAC. See notes Figure 10.
page 8 579-173 Rev. Q
Flex Amplifiers Installation Instructions
