Testing Of 30 Ma Rcds - Benning ST 725 Notice D'emploi

- Otherwise, the measurement of the protective conductor resistance (R
automatic polarity reversal and the highest measured value of both measurements will be
shown on the display.
- After the R test has been passed, the test of the protective conductor current I
PE
carried out as permanent measurement for max. 30 seconds. Press the
early the measurement.
- If the protective conductor current is lower than the admissible limiting value, a
shown next to the I
- The overall test is considered to be passed, if "PASS" is shown on the display.
- When pressing the
BENNING ST 725, the following warning will be shown on the display:
See figure 7b: Testing of three-phase appliances by means of active measuring adapters (test
object placed on insulated surface)
Note:
- The protective conductor current measurement is carried out using a current transformer
in the protective conductor of the measuring adapter (044140 or 044141) and by means of
the direct measurement method. The test object must be placed onto an insulated surface.
No part of the test object must have a connection to the earth potential. Otherwise, leakage
currents to earth might influence the measuring result.
- If it is not possible to place the test object onto an insulated surface, the protective conductor
current measurement can be carried out alternatively by means of the differential current
measurement method using the BENNING CM 9 leakage current clamp (044065). For this,
the test object must be put into operation by means of the optional measuring adapters
(044127 or 044128) and all active conductors (L1, L2, L3 and N) must be clamped by means
of the leakage current clamp. The BENNING CM 9 measures the protective conductor
current by means of the differential current measurement method.

9.5 Testing of 30 mA RCDs

The BENNING ST 725 allows measuring the tripping time of permanently installed RCDs and of
portable RCDs (PRCDs) with a nominal fault current of 30 mA. In the automatic test sequence,
the tripping time of the one-fold nominal fault current (initial polarity of 0°/ 180°) and of the five-
fold nominal fault current (initial polarity of 0°/ 180°) is measured.
By generating a fault current of 30 mA, it is proven that the RCD will trip when the nominal fault
current is reached. If the limiting value of the maximum contact voltage of 50 V is exceeded, the
"UB > 50 V" symbol will be shown on the display and the testing will be stopped.
07/ 2018
symbol.
LEAK
-key 7 without previously connecting the measuring adapter to the
BENNING ST 725

) will be started with
PE
will be
LEAK
-key 7 to finish
will be
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