User Manual

32 GMC-I Messtechnik GmbH
10.1 Earthing Resistance Measurement – Mains Operated
The following types of measurement or connection are possible:
• 2-pole measurement via 2-pole adapter
• 2-pole measurement via earthing contact plug
(not possible in IT systems)
• 3-pole measurement via 2-pole adapter and
probe
• Selective measurement: 2-pole measurement
with probe and current clamp sensor
At left in figure:
2-pole measuring
adapter for con-
tacting PE and L
measuring points
At right in figure:
The PRO-Schuko
measuring
adapter can be
used as an alter-
native.
Select Measuring Function
Select Operating Mode
The selected operating mode is displayed inversely:
mains~ in white against a black background.
Special Case: Manual Measuring Range Selection (test current
selection)
(R ≠ AUTO, R = 10 kΩ (4 mA), 1 kΩ (40 mA), 100 Ω (0.4 A),
10 Ω (3.7 ... 7 A), 10 Ω/U
E
)
Note
When the measuring range is selected manually, accuracy val-
ues are only valid starting at 5% of the upper limit range value
(except for the 10 Ω range; separate display for small values).
Set Parameters
❑ Measuring range: AUTO, 10 kΩ (4 mA), 1 kΩ (40 mA), 100 Ω
(0.4 A), 10 Ω (> 3.7 A)
In systems with RCCBs, resistance or test current must be se-
lected such that it is less than tripping current (½ I
ΔN
).
❑ Contact voltage: UL < 25 V, < 50 V, < 65 V, see section 5.7 re-
garding freely selectable voltage.
❑ Transformer ratio: depends on utilized current clamp sensor
❑ Connection type: 2-pole adapter, 2-pole adapter + probe,
2-pole adapter + clamp meter
❑ Type of system: TN or TT
❑ Test current waveform
See section 10.4 through section 10.6 regarding advisable parame-
ters for the respective measurement and connection types.
Perform Measurements
See section 10.4 through section 10.6.
10.2 Earthing Resistance Measurement – Battery Powered
(only MPRO & MXTRA)
The 5 following types of measurement or connection are possible:
• 3-Pole measurement via PRO-RE adapter
• 4-Pole measurement via PRO-RE adapter
• Selective measurement with clamp meter
(4-pole) via PRO-RE adapter
• 2-clamp measurement via PRO-RE/2 adapter
• Measurement of soil resistivity
ρ
E
via PRO-RE adapter
Figure at right:
PRO-RE adapter for connect-
ing earth electrode, auxiliary
earth electrode, probe and
auxiliary probe to the test
instrument for
3/4-pole measurement,
selective measurement and
measurement of soil resistivity
Figure at right:
PRO-RE/2 measuring adapter as
accessory for connecting the E-
Clip 2 generator clamp for 2-clamp
measurement and earth loop resis-
tance measurement.
Select Measuring Function
Select Operating Mode
The selected operating mode is displayed inversely:
white battery icon against black background.
Set Parameters
❑ Measuring range: AUTO, 50 kΩ, 20 kΩ, 2 kΩ, 200 Ω, 20 Ω
❑ Current clamp sensor transformer ratio:
1:1 (1 V/A,) 1:10 (100 mV/A), 1:100 (10 mV/A), 1:1000 (1 mV/A)
❑ Connection type: 3-pole, 4-pole, selective, 2-clamp, ρ
E
(Rho)
❑ Distance d (for measuring
ρ
E
): xx m
See section 10.7 through section 10.11 regarding advisable
parameters for the respective measurement and connection
types.
Perform Measurements
See section 10.7 through section 10.11.
R
E
R
E