Keithley 2657A, Reference Manual, Page: 82 / 805

Section 2: General operation Model 2657A High Power System SourceMeter® Instrument Reference Manual
2-58 2657A-901-01 Rev. B/December 2012
Item Description Qty Notes
(1) Protective earth (safety ground) for Model
2657A 1 Keithley Instruments Model CA-568-120 is a protective
earth (safety ground) cable assembly supplied with the
instrument.
(2) Interlock connection for Model 2657A 1 Pin 24 (INT) and Pin 22 (5 VDC) connected to test
fixture lid switch. Keithley Instruments Model 7709-308
is a 25-pin interlock male connector and can be used for
custom connections.
(3) Interlocked safety enclosure 1 Select a safety enclosure with an interlock that has a
normally-open (NO) switch
(4) Protective earth (safety ground) for test
fixture 1 Redundant grounds may be required for specific test
setups (for example, setups that clamp LO).
(5) Model HV-CA-571-3 high-voltage triaxial
female panel mount to unterminated cable
assembly 2 See schematic for connections. Make sure to follow the
specifications in
High-voltage triaxial cable termination
(on page 2-44).
(6) Model HV-CA-554 high-voltage triaxial
cable assembly (male to male) 2
(7) Model 2657A High Power System
SourceMeter
®
instrument
1
Noise shield
Use a noise shield (see following figure) to prevent unwanted signals from being introduced into the
test circuit. Low-level signals may benefit from effective shielding. The metal noise shield surrounds
the test circuit and should be connected to LO, as shown.
Guard voltage can be hazardous. With an unguarded device under test (DUT) connection, terminate
the guard before the end of the cable. Refer to High-voltage triaxial cable termination (on page 2-
44) for details.
Connect the enclosure of all metal test fixtures to protective earth (safety ground). See your specific
test fixture for information. Nonconductive test fixtures must be rated to double the maximum
capability of the test equipment in the system.
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.
WARNING
WARNING