Table 3-1. Stranded Copper Wire Ampere Capacity
Wire Size
AWG
22
20
18
16
14
12
10
8
6
4
Cross Section Area in mm2
0.75
1
1.5
2.5
4
6
10
Ampacity
5.0
8.33
10
15.4
13.5
19.4
16
31.2
25
40
32
55
40
75
63
100
135
Notes:
1. Ratings for AWG-sized wires derived from MIL-W-5088B. Ratings for metric-sized wires derived from IEC Publication
33-51.
.
2. Ampacity of aluminum wire is approximately 84% of that listed for copper wire.
3. When two or more wires are bundled together, ampacity for each wire must be reduced to the following percentages:
2 conductors 94%
3 conductors 89%
4 conductors 83%
5 conductors 76%
4.Maximum temperatures: Ambient = 50° C Conductor = 105° C
Local Sense Connections
Figure 3-12 illustrates a typical setup with module number 1 connected for constant current or constant resistance operation. Local sensing is used in applications where lead lengths are relatively short, or where load regulation is not critical. The sense switch must be set to LCL. Load leads should be bundled or tie-wrapped together to minimize inductance.
Remote Sense Connections
Figure 3-13 illustrates a typical setup with module number 1 connected for remote sense operation. The remote sense terminals of module 1 are connected to the output of the power supply. Remote sensing compensates for the voltage drop in applications that require long lead lengths. It is only useful when module 1 is operating in CV or CR mode, or when using voltage readback. The sense switch must be set to RMT. Load leads should be bundled or tie wrapped together to minimize inductance.
Parallel Connections
Figure 3-14 illustrates how modules can be paralleled for increased power dissipation. Up to six modules can be directly paralleled in CC or CR mode. Modules cannot be paralleled in CV mode. Each module will dissipate the power it has been programmed for. For example, if two modules are connected in parallel, with module number 1 programmed for 10 A and module number 2 programmed for 20 A, the total current drawn from the source is 30 A.
In Figure 3-14, all lead connections are terminated at the source. Each module is connected to the source using separate wires. Using the source as the current distribution point allows larger wires to be used for each module connection and also reduces the common impedance inherent in daisy-chained configurations.
If because of lead length or other considerations, lead connections cannot be made at the source, a remote distribution terminal may be required. Lead connections can also be daisy-chained across the module binding posts as long as the total current draw is less than the ampere-rating of AWG 8 wire (see Table 3-1). This is because two wires larger than AWG 8 cannot both fit inside an Electronic Load, binding post.
44 Installation
