Service manual

Test 2-2: DC Isolation Test
This test verifies that sufficient DC isolation exists between various points
on the switch module. The DMM used should be capable of measuring up to
at least 1 G
Ω. If the DMM indicates an overload, record the reading as
">R
max
", where R
max
is the highest resistance that the DMM can measure.
If the DMM is a 3458A, for example, the reading should be written as ">1.2
G
Ω".
Normally Open to
Common 1. Hardware Connections
2. Equipment Setup
• Set DMM to: 2-wire ohms, 1 GΩ range.
• Send *RST to the switch to open all NO contacts.
3. DC Isolation Reading
• Trigger the DMM and record the reading.
Figure 2-4. DC Isolation Test (NO Channels to Common)
Chapter 2 Verification Tests 27