Section 2: General operation
Model 2657A High Power System SourceMeter® Instrument Reference Manual
2-44
2657A-901-01 Rev. B/December 2012
LO, chassis ground, and protective earth (safety ground)
Connections to LO on the Model 2657A are not necessarily at 0 V. Hazardous voltages could exist
between LO and chassis ground. Make sure that high-voltage precautions are taken throughout the
test system. Alternatively, limit hazardous levels by adding external protection to limit the voltage
between LO and chassis. Failure to make sure high-voltage precautions are used throughout the test
system or a failure to limit hazardous levels could result in severe personal injury or death from
electric shock.
LO is electrically isolated from chassis ground. See
(on page 2-5) for location of chassis
ground connection, protective earth (safety ground) connection, and LO connections.
Using the chassis as a ground point for signal connections to the Model 2657A chassis may result in
higher or lower noise. The tie point to the chassis can help quiet measurements if the Model 2657A
common-mode current is channeled to the chassis instead of the device. However, if other equipment
is also connected to the chassis, higher noise (due to the other connected equipment) may result
when using the chassis as a ground point. If you choose to use the chassis as a ground point for
signal connections, use the Model 2657A chassis screw as a connection point.
Make connections to protective earth (safety ground) using the recommended wire size (#16 AWG or
larger) and securing with the ground screw.
High-voltage triaxial cable termination
When terminating the end of the high-voltage (HV) triax cable, pay particular attention to the voltage
spacings (see the following figure).
Figure 12: Voltage spacing
WARNING
NOTE
16.75 mm
7
6
5
4
3
2
1
Summary of Contents for 2657A
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