Operation Manual
71
IT system function Remarks
Continuity test
Rlow-Ω
independent of the selected power supply network
continuity test
Insulation independent of the selected power supply network
Line impedance
line impedance impedance Z
L1-L2
.
prospective short-circuit current I
PSC
for nominal U
L1-L2
.
Fault loop impedance not applicable
fault loop impedance
prospective fault current
Voltage, frequency symbols adapted to the IT system
Phase shift automatic recognition of three-phase mains
FI / RCD functions partly applicable
contact voltage Uc not applicable
tripping time
bridging,seegure11.3tripping current
automatic testing
Resistance to earth independent of the selected power supply network
PE conductor test key (TEST key) active,butdoesnotinuencetesting,ifavoltageis
detected
11.3.1 Voltage
Figure 11.2: Example of voltage and frequency measurements
Shown results for a single-phase system:
L1-L2 voltage between external conductors,
L1-PE voltage between external conductor 1 and protective conductor,
L2-PE voltage between external conductor 2 and protective conductor.
11.3.2 Line impedance
For further information, please refer to chapter 5.5 „Line impedance and prospective short-circuit
current“. The measuring method is the same, but the indication of the terminal voltage corres-
ponds to the IT system.
11.3.3 FI/RCD testing
The FI/RCD test is carried out in the same way as it is done in a TN/TT system (see chapter 5.3
„Residual current protection devices (FI/RCD)“. However, there is the following exception:
- The contact voltage measurement is irrelevant.
Thetestcircuitwithbridgingshouldcorrespondtothecircuitshowningure11.3.