Polarisation Index (Pi); Timed Insulation Resistance; Preventative Maintenance; Battery Replacement - Megger BM5200 Manual Del Usuario

Polarisation index (PI)

Polarisation Index (PI) test performs a test that calculates the
ratio of insulation resistance at ten minutes, IR
resistance at one minute, IR
indication of insulation polarisation when subjected to high
voltage DC. A high PI value indicates a high degree of insulation
polarisation and therefore good insulation condition. Generally the
PI value should be two or above.
Polarisation occurs at different rates ranging from minutes to
several hours which led the IEEE to create a ratiometric PI test. The
IEEE standard 43-2000, "Recommended Practice for Testing
Insulation Resistance of Rotating Machinery," limits the use of PI
test on winding systems to those with IR
MΩ.

Timed insulation resistance

The timed IR test is a test that automatically terminates after a
user adjustable time (t). Users can select SETUP on the range
switch and adjust timer (t) using up and down arrow buttons to
set the desired time followed by a single press of the PI-t (left
arrow) button. Default time (t) is set at one minute because
IR1min is frequently referred to in international standards.
9
to insulation
10 min
. This test provides a simple
1min
being less than 5000
1min

Preventative maintenance

No user serviceable parts
There are no user serviceable parts in the BM5200 except for the
batteries.
If an instrument's protection has been impaired it should not be
used, but sent for repair by suitably trained and qualified personnel.
The protection is likely to be impaired if for example, it shows
visible damage, fails to perform the intended measurements,
has been subjected to prolonged storage under unfavourable
conditions, or has been subjected to severe transport stresses.

Battery replacement

G
The battery contacts are not isolated from the test leads.
Remove the test leads from the instrument before opening
the battery compartment.
The cells are housed in a battery compartment in the base of the
instrument. To change the cells, use a PZ2 pozidrive screwdriver to
remove the battery cover securing screws and lift off the battery
compartment cover. Observing the correct polarity as marked on
the battery housing, install 8 replacement IEC LR6 (AA) cells.
Replace and secure the battery compartment cover on completion.
WARNING