Measuring Earth Electrode Potential (Function U E ) - Gossen MetraWatt PROFITEST MBASE MTECH Operating Instructions Manual

10.3 Measuring Earth Electrode Potential (function U
Earth Resistance Measurement with Probe (Mains Powered) – Connection Circuit Diagram
Ri
B
This measurement is only possible with a probe, see section 10.1.
Earth electrode potential U
E
earth electrode between the earth electrode terminal and refer-
ence earth if a short-circuit occurs between the phase conductor
and the earth electrode. The measurement of earth electrode
potential is required by Swiss standard SEV 3755.
Measuring Method
In order to determine earth electrode potential the instrument first
measures earth electrode loop resistance R
immediately thereafter earthing resistance R
stores both values and then calculates earth electrode potential
with the following equation:
U
E
The calculated value is displayed at the display panel.
Select the Measuring Function
R
E
Connection
Connected components: 2-pole adapter and probe
30
E
E
1
is the voltage which occurs at the
, and
ELoop
. -The instrument
E

U R
N E
= ---- ------------- -- -
R
ELoop
)
E
2
Set parameters
q Measuring range: 10  / U
q Connection type: 2-pole adapter + probe
q Contact voltage: UL < 25 V, < 50 V, < 65 V, freely adjustable
voltage, see section 5.7
q Transformer ratio: without significance in this case
R < limit value
E
 R
U
L
Start Measurement
Note
The following diagram appears if the
2-pole adapter is connected
incorrectly.
E
Limit value:
L
GMC-I Messtechnik GmbH
S