Leakage Current Measurement; Securing The Instrument - Benning CM 9 Bedienungsanleitung

crest factor from 2.0 to 2.5 additional error + 7 %
crest factor from 2.5 to 3.0 additional error + 7 %
max. crest faktor:
The stated accuracy is specified for 1 % to 100 % of the final measuring range
value and for conductors that are centrally clamped by means of the measuring
clamp 1 (see figures 2 to 7). For conductors that are not centrally clamped, an
additional error of 1 % of the display value needs to be taken into account. Filter
damping characteristic - 24 db/ oct, filter limit frequency: 100 Hz
Influence of a magnetic field of parallel lines: 0.04 % typical value.
*2 The measuring value can roll within +/- 3 digits
8. Measuring with the BENNING CM 9
8.1 Preparations the measurement
Operate and store the BENNING CM 9 only at the specified storage and opera-
ting temperatures conditions. Avoid continuous insulation.
- Strong sources of interference in the vicinity of the BENNING CM 9 might
lead to unstable readings and measuring errors.
- To simplify operation, the BENNING CM 9 is provided with an automatic
background lighting. As soon as the ambient lighting decreases, the back-
ground lighting of the current clamps will switch on.

8.2 Leakage current measurement

8.2.1 Leakage current measurement at the ground conductor
see figure 2:
8.2.2 Differential current measurement at single­phase systems
see figure 3:
8.2.3 Leakage current measurement via ground conductor (charge
eliminator) for three­phase supply
see figure 4:
8.2.4 Differential current measurement, load supplied in three­phase,
without N­type conductor
see figure 5:
8.2.5 Differential current measurement, load supplied in three­phase,
with N­type conductor
see figure 6:
8.2.6 Alternating current measurement
see figure 7:
9. Maintenance
Before opening the BENNING CM 9, make sure that it is free of
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voltage! Electrical danger!

9.1 Securing the instrument

Under certain circumstances safe operation of the BENNING CM 9 is no longer
ensured, for example in the case of:
- Visible damage of the casing.
- Incorrect measurement results.
- Recognizable consequences of prolonged storage under improper condi-
tions.
- Recognizable consequences of extraordinary transportation stress.
In such cases the BENNING CM 9 must be switched off immediately, discon-
nected from the measuring points and secured to prevent further utilization.
9.2 Cleaning
Clean the exterior of the housing with a clean dry cloth (exception: special clean-
ing wipers). Avoid using solvents and/ or scouring agents for cleaning the instru-
ment. It is important to make sure that the battery compartment and battery
contacts are not contaminated by leaking electrolyte.
If electrolyte contamination or white deposits occur in the area of the batteries or
battery compartment, clean them too with a dry cloth.
06/ 2016
1,6
2,0
3,0
leakage current measurement at the ground conductor
differential current measurement at single-phase systems
leakage current measurement via ground conductor (charge
eliminator) for three-phase supply
differential current measurement, load supplied in three-phase,
without N-type conductor
differential current measurement, load supplied in three-phase,
with N-type conductor
alternating current measurement
BENNING CM 9
5000 - 6600 digits
3000 - 5000 digits
0 - 3000 digits
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