National Instruments RMX-410 Series, User Manual

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36
NATIONAL
INSTRUMENTS
Wire size
AWG Resistivity
Ohm/1000ft Maximum length in feet to limit
voltage drop to 1V or less
5A 10A 20A 50A 80A
14 2.526 80 40 20 8 5
12 1.589 120 60 30 12 7.5
10 0.9994 200 100 50 20 12.5
8 0.6285 320 160 80 32 20
6 0.3953 500 250 125 50 31
4 0.2486 800 400 200 80 50
2 0.1564 1200 600 300 125 78
Table 3-2: Maximum wire length for 1V drop on lead (in feet)
Cross sect.
area
(mm
2
)
Resistivity
Ohm/Km Maximum length in meters to limit
voltage drop to 1V or less
5A 10A 20A 50A 80A
2.5 8.21 24.0 12 6 2.4 1.5
4 5.09 39.2 18.6 9.8 4 2.5
6 3.39 59.0 29.4 14.8 5.8 3.6
10 1.95 102.6 51.2 25.6 10.2 6.3
16 1.24 160.0 80 40 16 10
25 0.795 250.0 125 62 25.2 15.7
35 0.565 354.0 177 88 35.4 22
Table 3-3: Maximum wire length for 1V drop on lead (in meters)
For currents not shown in Table 3-2 and 3-3, use the formula:
Maximum length=1000/(current x resistivity)
Where current is expressed in amperes and resistivity in ohms/km or ohms/1000ft.