Manual

Gossen Metrawatt GmbH 63
15.5 Earthing Resistance Measurement, Mains Powered – Measuring Earth Electrode Potential (U
E
Function)
This measurement is only possible with a probe (see section
15.4). Earth electrode potential U
E
is the voltage which occurs at
the earth electrode between the earth electrode terminal and ref-
erence earth if a short-circuit occurs between the phase conduc-
tor and the earth electrode. The measurement of earth electrode
potential is required by Swiss standard NIV/NIN SEV 1000.
Measuring Method
In order to determine earth electrode potential the instrument first
measures earth electrode loop resistance R
ELoop
, and immedi-
ately thereafter earthing resistance R
E
. The instrument stores both
values and then calculates earth electrode potential with the fol-
lowing equation:
The calculated value is displayed at the display panel.
Select Measuring Function
Select Operating Mode Select Measuring Range
Connection
To be connected: 2-pole adapter and probe
Set Parameters
❏ Measuring range: 10  / U
E
❏ Connection: 2-pole adapter + probe
❏ Touch voltage: UL < 25 V, < 50 V, < 65 V, see section 10.8
regarding freely selectable voltage
❏ Test current waveshape: sinusoidal only in this case (full-wave)!
❏ System type: TN/TT, IT
❏ Transformer ratio: irrelevant in this case
Start Measurement
Note
The following diagram appears if the
2-pole adapter is connected incor-
rectly.
T
E
S
T
I
N
S
T
R
U
M
E
N
T
Ri
W
a
t
e
r
P
i
p
e
SE
2
E
1
B
U
E
U
N
R
E

R
ELoop
--------------------=
R
E
Limit Value:
R
E
> Limit Value
U
L
 R
L