Performing Individual Tests - Unitest Telaris 0751 Instruction Manual

Measuring the PE Resistance

6.0 Performing Individual Tests

6.1 Measuring the PE Resistance (Earth Bond)
6.1.1 General Information regarding the PE
resistance Measurement
Before any PE resistance measurement it must
be ensured that the UUT is not connected to live
voltages.
During the measurement, the mains lead must
be moved across the total length in sections,
whereby no measurement result fluctuation
must occur. A fluctuating measurement result
indicates an error.
For appliances equipped with additional metal
connections, such as e.g.
• water connection (e.g. washing machine)
• gas connection (e.g. warm water heating unit)
or
• antenna connection (e.g. SAT-Receiver) the
measurement result might be falsified due to
the additional connection to the PE resistance.
The PE resistance connection via an additional
connection must be removed when performing
the measurement.
For the appliance UNITEST TELARIS 0751 the
test current is an AC current. The key "Display"
(17) is used to display the measurement val-
ues for both polarities during active measure-
ment. Measurement results showing high dif-
ferences for the two polarities indicate an
insufficient PE connection. Thus, corroded
connections to the PE resistance can be deter-
mined.
20
In compliance with DIN VDE 0701, Part 1 and
DIN VDE 0702, Part 1, the minimum test cur-
rent is 200 mA.
For appliances equipped with mains lines of up
to 5 m, the limit value amounts to 0.3 Ω in com-
pliance with DIN VDE 0701/0702 0,3 Ω, i.e. for
active limit value display 'LIMIT 0.3 Ω' the sym-
bols and 'LIMIT' may not be displayed!
When dealing with longer connection cables,
the limit value is to be defined in accordance
with the standard applied.
According to DIN VDE 0751 the limit value is
0,3 Ω, i.e., if the limit value indicator is swit-
ched on 'LIMIT 0,3 Ω' the symbols and 'LIMIT'
must not appear! If the connection lines are of
a certain length, the limit value must be defined
in accordance with the respective standard
applied.