2 Installation
Wire Sizing
FIRE HAZARD Select a wire size large enough to carry short-circuit current without
overheating (refer to the following table). To satisfy safety requirements, load wires
must be heavy enough not to overheat while carrying the short-circuit output current
of the unit. Keysight Model N678xA SMU wiring requirements are described in the
following section.
Along with conductor temperature, you must also consider voltage drop when selecting wire sizes.
The following table lists the resistance for various wire sizes and the maximum lengths to limit the
voltage drop to 1.0 V per lead for various currents.
Note that the minimum wire size required to prevent overheating may not be large enough to prevent
over-voltage tripping or maintain good regulation. Under most conditions, the load wires should also
be heavy enough to limit the voltage drop to no more than l.0 V per lead.
To help prevent nuisance tripping of the over-voltage circuit, select a wire size sufficient to handle the
FULL output current of the unit no matter what the intended load current or current limit setting
Load lead resistance is also an important factor relating to the CV stability of the instrument when
remote sensing capacitive loads. If high capacitance loads are expected, you should not use wire
gauges heavier than 12 to 14 AWG for long runs of load lead.
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Keysight N6700C Series User's Guide