Benning CM 9-2 - Maintenance; Measuring with the BENNING CM

10/ 2019 BENNING CM 9-2
13

E13 Contact current caused by common-mode
rejection
-
E14 Frequency -
E15 Repeatability -
Intrinsic uncertainty (A) see measuring accuracy, sections 7.1
Operating uncertainty (B) 10 A/ m 30 A/ m
Measured value 3.5 mA to 10 mA < 15 % < 20 %
Measured value > 10 mA < 10 % < 12.5 %
8. Measuring with the BENNING CM 9-2
8.1 Preparing the measurement
OperateandstoretheBENNINGCM9-2atthespeciedstorageandoperating
temperaturesonly!Donotpermanentlyexposethedevicetosunlight.
- Strong sources of interference in the vicinity of the BENNING CM 9-2 might
involveunstablereadingsandmeasuringerrors.
8.2 Current measurement

Do not exceed the maximum permitted voltage with respect to
earth potential!
Electrical danger!
- PresstheON/OFFkey
8
toswitchontheBENNINGCM9-2.
- If necessary, press the LPF key
5
toenablethelow-passlter(50Hzto
60Hz)orthedevicelter(1kHz).
- Operateopeninglever
3
, clamp
1
singlewireliveconductorcentrallyby
meansoftheBENNINGCM9-2currentprobe.
- Reado󰀨thedigitaldisplayunit
6
.
8.2.1 Leakage current measurement at the ground conductor
Seegure2: Leakagecurrentmeasurementatthegroundconductor
8.2.2 Differential current measurement at single-phase systems
Seegure3: Di󰀨erentialcurrentmeasurementatsingle-phasesystems
8.2.3 Leakage current measurement via ground conductor (charge
eliminator) for three-phase supply
Seegure4: Leakagecurrentmeasurementviagroundconductor(charge
eliminator)forthree-phasesupply
8.2.4 Differential current measurement, load supplied in three-phase,
without N-type conductor
Seegure5: Di󰀨erential current measurement, load supplied in three-
phase,withoutN-typeconductor
8.2.5 Differential current measurement, load supplied in three-phase,
with N-type conductor
Seegure6: Di󰀨erential current measurement, load supplied in three-
phase,withN-typeconductor
8.2.6 Alternating current measurement
Seegure7: Alternatingcurrentmeasurement
9. Maintenance

Before opening the BENNING CM 9-2, make sure that it is free of
voltage! Electrical danger!
9.1 Securing the instrument
Under certain circumstances safe operation of the BENNING CM 9-2 is no
longerensured,forexampleinthecaseof:
- Visibledamageofthecasing.
- Incorrectmeasurementresults.
- Recognisableconsequences ofprolonged storageunder impropercondi-
tions.
- Recognisableconsequencesofextraordinarytransportationstress.