Section 2: General operation
Model 2461 Interactive SourceMeter® Instrument Reference Manual
2-96
2461-901-01 A/November 2015
To provide protection from shock hazards, an enclosure should be provided that surrounds
all live parts.
Nonconductive enclosures must be constructed of materials that are suitably rated for
flammability and the voltage and temperature requirements of the test circuit. 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.
For metallic enclosures, the test fixture chassis must be properly connected to protective
earth (safety ground). A grounding wire (#16 AWG or larger) must be attached securely to
the test fixture at a screw terminal designed for safety grounding. The other end of the
ground wire must be attached to a known protective earth (safety ground).
When hazardous voltages (>30 V
RMS
, 42 V
PEAK
) will be present, the test fixture must meet the
following safety requirements:
•
Construction material
: A metal test fixture must be connected to a known protective earth
(safety ground) as described in the above warning. A nonconductive test fixture must be
constructed of materials that are suitable for flammability, voltage, and temperature conditions
that may exist in the test circuit. The construction requirements for a nonconductive enclosure are
also described in the warning above.
•
Test circuit isolation
: With the lid closed, the test fixture must completely surround the test
circuit. A metal test fixture must be electrically isolated from the test circuit. Internally, Teflon
standoffs are typically used to insulate the internal printed circuit board or guard plate for the test
circuit from a metal test fixture.
•
Interlock switch
: The test fixture must have a normally open interlock switch. The interlock
switch must be installed so that when the lid of the test fixture is opened, the switch will open, and
when the lid is closed, the switch will close. The Model 2461 includes an interlock connector on
the rear panel of the instrument. When properly connected to a test fixture, the output of the
Model 2461 is limited to ±42 V when the lid of the test fixture is open.