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2. Wire size should be selected to enable voltage drop per lead to be less than 1.0V at the rated Output
current. Although units will compensate for up to 5V in each load wire, it is recommended to minimize the
voltage drop (1V typical maximum) to prevent excessive output power consumption from the power supply
and poor dynamic response to load changes. Please refer to Tables 3-2 and 3-3 for maximum wire length
(to limit voltage drop) in American and European dimensions respectively.
Wire size
(AWG)
14
12
10
8
6
4
2
0
Table 3-2: Maximum Wire Length for 1V Drop Across Lead (in feet)
Cross Sect.
area
(mm²)
2.5
4
6
10
16
25
35
Table 3-3: Maximum Wire Length for 1V Drop Across Lead (in meters)
where current is expressed in Amperes and resistivity in ohms/km or ohms/1000ft.
3.9.3
Wire Termination
The wires should be properly terminated with terminals securely attached. DO NOT use unterminated wires for
load connection at the power supply.
When local sensing, a short from "+LS or +S" to " –V or –S or –LS" (or "–
LS or –S" to "+V or +S or +LS"), will cause damage to the power supply.
Reversing the sense wires might cause damage to the power supply in
local and remote sensing. (Do not connect "–S" to +V" or "+S to –V").
3.9.4
Noise and Impedance Effects
To minimize the noise pickup or radiation, the load wires and remote sense wires should be twisted pairs to the
shortest possible length. Shielding of sense leads may be necessary in high noise environments. Where
shielding is used, connect the shield to the chassis via a rear panel Ground screw. Even if noise is not a
concern, the load and remote sense wires should be twisted-pairs to reduce coupling, which might impact the
stability of the power supply. The sense leads should be separated from the power leads.
Resistivity
(Ohms/1000ft)
10A
2.526
40
1.589
60
0.9994
100
0.6285
160
0.3953
250
0.2486
400
0.1564
600
0.0983
1000
Resistivity
Ohms/km
10A
8.21
12.0
5.09
18.6
3.39
29.4
1.95
51.2
1.24
80.0
0.795
125.0
0.565
177.0
For currents not shown in Table 3-2 and 3-3, use the formula:
Maximum length = 1000/(current x resistivity)
CAUTION
83-517-000 Rev. A
Maximum Length in feet to Limit
Voltage Drop to 1V or less
20A
50A
100A
20
8
4
30
12
6
50
20
10
80
32
15
125
50
25
200
80
40
300
125
60
500
200
100
Maximum length in meters to limit
voltage drop to 1V or less
20A
50A
100A
6.0
2.4
1.2
9.8
4.0
2
14.8
5.8
2.9
25.6
10.2
5.1
40.0
16.0
8
62.0
25.2
12.6
88.0
35.4
17.7
28
200A
400A
2
---
3
---
5
2
8
4
12
6
20
10
30
15
50
25
200A
400A
0.6
0.3
1.0
0.5
1.45
0.7
2.5
1.25
4
2
6.3
3.1
8.8
4.4
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