6. Dead circuit tests
6.1 General
Whenever possible, you should use dead circuit tests (tests on circuits that are de-energized and isolated) in
preference to live circuit tests. The dead circuit test functions provided by MFT-X1 series instruments are Continuity
testing, Insulation Resistance measurement and Earth resistance measurement.
WARNING : Before carrying out dead circuit tests, you should isolate the circuit you are working on and
follow approved procedures to confirm that it is de-energized and that it cannot be accidentally
re-energized while you are carrying out the tests.
6.2 Protection against accidental damage
MFT-X1 instruments are protected against the damage that might otherwise occur if you select a dead circuit test and
connect the instrument to live circuit. The protection is effective even if you’ve started a live circuit test and locked it
on. If you do accidentally connect to a live circuit, the instrument will warn you and inhibit or stop the test. In some
circumstances, the instrument’s internal fuse may fail, and you will need to replace it before you can carry out further
tests. You must always use the correct type of fuse Refer to 18.5 Fuse and fuse replacement on page 102.
Live circuit warnings for dead circuit tests are displayed as below:
Fig 10: Insulation live circuit warning
This warning prevents the test from starting or stops a test if a hazardous voltage appears during the test.
www.megger.com MFT-X1
25
Dead circuit tests
To Next Page
Loading...
Need help?
General
