MI 2126 Earth 2/3
Using instrument
14
Step 3
TEST
Press the
TEST
key and view test result. If you want to perform more
than one measurement press the
TEST
key and keep it pressed until
the result is stabilized, then release the key. The last result will stay
displayed.
DISP
Press the
DISP
key to check the resistances of both the potential (
Rp)
,
and the current (
Rc)
test probes. After a short period the main result
will automatically be displayed again.
Notes
:
•
When an external voltage higher than 20 V a.c. is present between blue (H),
black (E) and red (S) test terminals, the earth resistance measurement will
not be carried out after pressing the TEST key. The message 20 V will be
displayed instead, marked with
symbol!
•
If a noise voltage higher than approx. 5 V is present between the blue (H) and
black (E) or red (S) test terminals, symbols
~
and
will be displayed,
indicating that the test result may not be correct!
•
The instrument does not indicate if a DC voltage is present at the input
terminals.
•
DC voltage have no influence on the measurement.
•
If the resistance of the current or potential rod is too high (>(4 k
Ω
+ 100xR
E
)
or >50 k
Ω
, whichever is lower), then the result will be marked with
symbol.
•
If the test result is out of measurement range o.r. message will be displayed.
3.3 General settings
There is usually voltage or current noise present on the earthing system under test,
caused by mains voltage somewhere in the near or far vicinity. Mains voltage frequency
is different between countries (e.g. 50 Hz in the European countries, 60 Hz in the United
States). In order to get stable test results, regardless of noise levels, it is advisable to
set the nominal frequency of the mains system.
The instrument measuring system assures excellent noise immunity. In extremely noisy
conditions, the stability of results can be further improved by means of averaging.
The frequency and algorithm, once set, will be effective even after replacing batteries.
