Spectrex 20/20F - Fast UV/IR Flame Detector - Manual (Page 33)

Spectrex Inc. - SharpEye TM UV/IR (F) Flame Detector Manual – TM756100 Rev A, July 2005
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Appendix A - Wire Selection Tables
G
ENERAL I NSTRUCTION FOR E LECTRICAL W IRING :
1. Refer to Table 7 to determine the required wire gauge for general wiring, such
as relay wiring. Calculate the permitted voltage fall with respect to loads
current, wire gauge, length of wires.
2. Refer to Table 8 to select wire gauge for detectors power supply wires. DO
NOT connect any device or load to detectors supply inputs.
Table 7. Maximum DC resistance at 68°F for copper wire
AWG mm
2
Ohm per
100 ft.
Ohm per
100 meter
26 0.12 - 0.15 4.32 14.15
24 0.16 - 0.24 3.42 11.22
22 0.30 - 0.38 1.71 5.60
20 0.51 - 0.61 1.07 3.50
18 0.81 - 0.96 0.67 2.20
16 1.22 - 1.43 0.43 1.40
14 1.94 - 2.28 0.27 0.88
12 3.09 - 3.40 0.17 0.55
10 4.56 - 6.64 0.11 0.35
Wiring Gauge
1 Select “No. of detectors” connected on one circuit.
2 Select “wiring length” per your installation requirements.
3 Refer to “Power Supply Range” for voltage extreme applied.
Table 8. Wiring length in feet (meter)
No. of
Detectors Recommended Wire Diameter Power Supply
Range (VDC)
24 18 16 14 - - 22-32
20 18 16 14 - - 22-32
16 20 18 16 14 - 22-32
12 20 18 16 14 - 20-32
8 20 18 16 14 - 20-32
4 and less 20 18 16 16 14 20-32
Feet 164 328 492 656 820
(meter) (50) (100) (150) (200) (250)
Max. Length from Power Supply to Last
Detector