Insulation Resistance (Hipot) Tests (7751/7753 Only) - Keithley 2790 User Manual

Model 2790 SourceMeter

Insulation resistance (HIPOT) tests (7751/7753 only)

WARNING
There are three basic tests for insulation resistance. Two preliminary verification tests and
the HIPOT test.
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Single stage inflator connections to the 7751/7753 module are shown in
dual stage inflator connections are shown in
all three tests for insulation resistance.
NOTE
®
Switch System User's Manual
The Models 7751 and 7753 are provided with outputs that are poten-
tially hazardous if not connected properly. It is the responsibility of the
customer to operate instruments in a safe manner. Be sure to read and
follow all installation and operating instructions before attempting to
use the 7751/7753 HIPOT function.
Contact checks — These checks use the ohmmeter of the Model 2790 to verify that
the V-source test circuit is properly connected to the inflator housing and the
bridgewire.
V-source readback — This test uses the voltmeter of the Model 2790 to measure
the actual output of the V-source. This test should be done before every HIPOT test
to ensure that the programmed voltage is being used.
Cable discharge — Summarizes cable discharge which is used to dissipate energy
stored in the test cables and the module by the V-source.
HIPOT test — This test measures the insulation resistance of the inflator.
The interlock of the 7751/7753 must be enabled in order to use the
V-source. Figure 5-6
Figure 5-5. These connections accommodate
shows how interlock is enabled.
5-17
Figure 5-3, while