Insulation Measurement; Resistance - Chauvin Arnoux C.A 6531 Notice De Fonctionnement

These warnings only end if the voltage falls below 25 V
(disconnection of the leads or removal of the voltage) or if the
yellow key is released or, naturally, if you turn off the instrument
by returning the switch to the OFF position.
The instrument indicates if the value measured is outside
its measurement range. Above 600 V, the digital display
indicates OL.

3.1.2 Insulation Measurement

If there is not a dangerous voltage (see § 3.1.1.), the user can
then measure the insulation by pressing the yellow key. The high
voltage is then generated between the terminals (marked + and -
). The value of the measurement is shown on the logarithmic
scale of the bargraph and on the digital display, with the
corresponding MΩ or GΩ symbol. As soon as the yellow key is
released, the instrument returns to voltage measurement mode.
If the voltage generated may be dangerous, the
is displayed.
The instrument indicates if the value measured is outside
its measurement range. If the insulation resistance is greater
than 400 MΩ (C.A 6531), 2 or 20 GΩ (C.A 6533), the OL symbol
is displayed on the digital measurement display. When the
measurement is greater than 1.1 GΩ (even on the C.A 6531),
the symbol lights up on the right-hand side of the bargraph.
Similarly, the digital measurement display indicates " - - - " if the
insulation resistance is less than:
C.A 6531
10 kΩ at 50 V or 20 kΩ at 100 V
C.A 6533
10 kΩ at 50 V, or 20 kΩ at 100 V, or 50 kΩ at 250 V, or 100 kΩ at
500 V
When the measurement is less than 70 kΩ Ω Ω Ω Ω , only the
lights up on the left-hand side of the bargraph.
To measure high insulation values, you are advised to use the
"G" guard terminal to remove the influence of superficial leak
currents and "hand capacitance" (see § 10.2.2).
3.2

Resistance

Resistance measurement corresponds to the 40 kΩ position of the
switch on the C.A 6531 and the 400 kΩ position on the C.A 6533.
The measurement is indicated on the digital measurement
display, accompanied by the Ω or kΩ symbol if necessary.
Resistance measurements shall be performed on idle
circuits.
The instrument indicates if the value measured is outside
its measurement range. If the resistance is greater than 40 kΩ
or 400 kΩ, depending on the instrument, the OL symbol is
displayed on the digital measurement display.
A programmed threshold may trigger an alarm (see § 4.5).
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symbol
symbol