MEGABRAS MD 5060x Manual De Uso página 20

The polarization index is the ratio between the insulation resistance value
measured after 10 min and the value measured after 1 min. This index is
useful to determine whether it is necessary to perform preventive and
predictive Maintenance in order to detect any insulation resistance wear
and tear due to the excess of dust, dirt, grease, or else the action of
chemical or physical agents, etc.
6.2. Dielectric Absorption Index (DAI)
The key makes it possible to visualize the Dielectric Absorption Index
value on the display. For this kind of test, the equipment should be
connected, applying voltage to the sample for 60 seconds. After this
period, the operator must press the
value on the display. If this key is pressed before the 1-minute period has
elapsed, the display will show DAI = - - -.
The Dielectric Absorption Index is the ratio between the insulation
resistance value measured after 60 seconds and the value measured
after 30 seconds. This value is useful to determine whether it is necessary
to perform preventive and predictive maintenance on the coils
(transformers, engines and motors, generators, etc.).
R
10 minutes
PI
=
R
1 minute
key to read the absorption index
R
60 seconds
DAI
=
R
30 seconds
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