Low voltage cable ratings
Table 1
communication bus — communication cables
Item
Description
Cable type
Twisted and shielded
Minimum gauge
1 mm2 (18 AWG)
Maximum cable length (including cable extensions)
1200 meters (4000 feet)
Certification and type
CSA, CMG FT4 type, 18 AWG, 600 V, 75 °C (167 °F)
UL, AWM or CM ttype, 18 AWG, 600 V, 75 °C (167 °F)
Characteristic Impedance
120 Ω +/- 12
Inductance
0.258 µH/ft, Nominal
Mutual Capacitance
12 pf/ft @1 kHz, Nominal
Velocity of propagation
75%
Conductor DCR
6.9 Ω/1000ft @20°C, Nominal
OA Shield DCR
1.8 Ω/1000ft @20°C, Nominal
Attenuation (Max dB/100ft)
0.13 @ 125 kHz
0.25 @ 500 kHz
0.36 @ 1 MHz
Number of Twists
2.4 Twists/foot (min)
Table 2
DC Power cables
Item
Description
Wire gauge
18 AWG
16* AWG
14 AWG
12 AWG
10 AWG
1 pair twisted
shielded
1 pair twisted
shielded
1 pair twisted
shielded
1 pair twisted
shielded
1 pair twisted
shielded
Max. length
150m (500 feet)
300m (1000
feet)
600m (2000
feet)
900m (3000
feet)
1200m (4000
feet)
Inductance
Nominal
0.17 μH/ft
0.174 μH/ft
0.16 μH/ft
0.16 μH/ft
0.14 μH/ft
ConductorDCR
@20°C, Nominal
6.1 Ω/1000ft
3.6 Ω/1000ft
2.6 Ω/1000ft
1.63 Ω/1000ft
1.09 Ω/1000ft
Certification and
type
CSA, TEW type, 600 V, 105 °C (221 °F)
UL, 1015 type, 600 V, 105 °C (221 °F)
