Chauvin Arnoux C.A 6545 Notice De Fonctionnement page 44

Automatic DAR or PI measurement:
If the R-DAR-PI-DD key is actuated during the voltage measurement before the start of a
measurement, the display is as follows:
→
- - - - MΩ
↑
and the value of the input current (between terminals "+" and "-") + is indicated
Note: The input current may be a depolarisation current resulting from an earlier insulation
measurement. It is recommended to start a new DAR and PI measurement after the current has
dropped to a negligible value (on the order of 100 pA) to avoid variations on these measurements.
Depending on the choice (DAR, PI or DD), here is the measurement procedure:
a) DAR: press START → the DAR symbol flashes and the display indicates «- - - -» as long as the
calculation of the coefficient is impossible (t < 1 min).
For example:
After 1 min. the measurement stops, the DAR symbol becomes steady and the main display
automatically shows the DAR value.
The R-DAR-PI-DD key may be used during and after the measurement to see the insulation
measurement performed, but it does not provide the PI value, since the measurement did not
last long enough.
b) PI: press START → the PI symbol flashes and the display indicates «- - - -» as long as the
calculation of the coefficient is impossible (t < 10 min
For example:
*
After 10 min . the measurement stops, the PI symbol becomes steady and the main display
automatically shows the PI value.
During and after the measurement, the R-DAR-PI-DD key is used to display the DAR (after 1
min), the PI (after 10 min.
c) DD: press START → the DD symbol flashes and the display indicates «- - - -» as long as the
calculation of the coefficient is impossible (t < 30 min.* + 1 min.).
For example:
1 min. after the measurement stops, the DD symbol becomes steady, the display automatically
shows the value of DD.
Therefore: if the measurement lasts 1 min. → DAR
if the measurement lasts 10 min. → PI
if 1 min. after the end of the measurement → DD
Note: If, during the measurement of DAR, PI or DD, automatic or not, a major external parasite
voltage appears, or if the insulation resistance exceeds the measuring range of the device, the
DAR or PI measurements are stopped and the screen shows:
DAR MΩ
These measurements resume as soon as the parasite voltage disappears.
The display of the DD value is:
- unknown (- - - -) if C < 1 nF and Idd < 100 pA
- known and flashing if 1 nF ≤ C < 10 nF and 100 pA ≤ Idd < 1 nA
- known and permanent if C ≥ 10 nF and Idd ≥ 1 nA
(with C = measured capacitance and Idd = measured leakage current)
→
DAR - - - - PI - - - -
DAR - - - -
PI - - - -
*
) and the insulation measurement.
DD - - - -
or PI MΩ
44
→
DD - - - -
*
).
or DD MΩ