Measuring With The Benning Cm; Maintenance - Benning CM 9-2 Operating Manual

E13 Contact current caused by common-mode
rejection
E14 Frequency
E15 Repeatability
Intrinsic uncertainty (A)
Operating uncertainty (B)
Measured value 3.5 mA to 10 mA
Measured value > 10 mA
8.

Measuring with the BENNING CM 9-2

8.1 Preparing the measurement
Operate and store the BENNING CM 9-2 at the specified 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 filter (50 Hz to
60 Hz) or the device filter (1 kHz).
- O perate opening lever 3 , clamp 1 single wire live conductor centrally by
means of the BENNING CM 9-2 current probe.
- Read off the digital display unit 6 .
8.2.1 Leakage current measurement at the ground conductor
See figure 2:
8.2.2 Differential current measurement at single-phase systems
See figure 3:
8.2.3 Leakage current measurement via ground conductor (charge
eliminator) for three-phase supply
See figure 4:
8.2.4 Differential current measurement, load supplied in three-phase,
without N-type conductor
See figure 5:
8.2.5 Differential current measurement, load supplied in three-phase,
with N-type conductor
See figure 6:
8.2.6 Alternating current measurement
See figure 7:
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
l onger ensured, for example in the case of:
- Visible damage of the casing.
- Incorrect measurement results.
- R ecognisable consequences of prolonged storage under improper condi-
tions.
- Recognisable consequences of extraordinary transportation stress.
10/ 2019
Leakage current measurement at the ground conductor
Differential current measurement at single-phase systems
L eakage current measurement via ground conductor (charge
eliminator) for three-phase supply
D ifferential current measurement, load supplied in three-
phase, without N-type conductor
D ifferential current measurement, load supplied in three-
phase, with N-type conductor
Alternating current measurement
BENNING CM 9-2
-
-
-
see measuring accuracy, sections 7.1
10 A/ m
< 15 %
< 10 %

30 A/ m
< 20 %
< 12.5 %
13