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CHAPTER 3:
Installation
Model 648 Electromagnet Power Supply
3.9 Magnet Cable
Connections
Magnet cable connections are made at the and - terminals on the rear
panel. These plated copper bus bars accommodate M8 (
5/bg
in) mounting hardware.
Two M8 bolts, nuts, and Belleville washers are provided. Use load wires heavy enough
to limit the voltage drop to less than 0.5 V per lead. This ensures proper regulation
and keeps the cables from overheating while carrying the required output current.
TABLE 3-3 lists the current capacity and lead lengths for load connections. Lake Shore
sells magnet cables in 10 ft and 20 ft lengths. Refer to section 1.11 for ordering
accessories.
FIGURE 3-13 shows how the output cables are connected to the Model 648. A plain
washer and a spring or Belleville washer are provided. The Belleville washer is
required to maintain contact pressure through varying material thickness due to
heating. The magnet leads should be dressed straight down to allow the installation
of the mandatory protective lug cover. Lug cover installation is shown in FIGURE 3-13.
If the protective lug cover is not installed, the unit will not power up.
Current capacity and total lead lengths
AWG
Area (mm2)
Capacity (A)
Resistivity ohms/1000 feet
Distance to magnet
Max output of 135 A
0
53.5
245
0.09827
22 M (72 ft)
2
33.6
180
0.1563
14 M (45 ft)
4
21.2
135
0.2485
8.5 M (28 ft)
Output cable connection; Right: Output lug cover installation
TABLE 3-3
FIGURE 3-13
