Keithley 2790, User Manual, Page: 86 / 130

Model 2790 SourceMeter
®
Switch System User’s Manual 5-17
Insulation resistance (HIPOT) tests (7751/7753 only)
WARNING 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.
There are three basic tests for insulation resistance. Two preliminary verification tests and
the HIPOT test.
• 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.
Single stage inflator connections to the 7751/7753 module are shown in Figure 5-3 , while
dual stage inflator connections are shown in Figure 5-5 . These connections accommodate
all three tests for insulation resistance.
NOTE The interlock of the 7751/7753 must be enabled in order to use the
V-source.
Figure 5-6 shows how interlock is enabled.