User manual

6 GMC-I Messtechnik GmbH
Minimum Permissible Limit Values for Insulation Resistance
Relative to Insulation Test Voltage per EN 62446
Note
If the limit value is fallen short of,
<1M or < 0.5 M appears for R
ISO
.
Example
9.5 General Insulation Resistance Measurement
The PROFITEST PVSUN test instrument is additionally equipped with
system-independent insulation testing. This is helpful, for exam-
ple, when testing systems or supply lines when no modules have
yet been installed. All insulations tests known to date can be per-
formed.
Warning!
The test object must be potential-free. Assure absence
of voltage with the help of a suitable measuring instru-
ment, for example the METRAVOLT 12D+L voltage tester.
Note
General insulation measurement is executed between
short circuited (–) and () terminals.
➭ Connect the (–) and () terminals at the PROFITEST PV
SUN to the
device under test.
➭ Switch the PROFITEST PV
SUN test instrument on.
Selecting the Test Voltage
➭ Press and hold the RISO/250V/500V/1000V key for at least 2
seconds.
The currently selected test voltage appears at the display.
➭ Select the required insulation test voltage by briefly and re-
peatedly pressing the R
ISO
/250V/500V/1000V key.
The last selected value is saved after a short period of time, and is
then cleared from the display.
Example
Executing the Insulation Resistance Measurement
➭ Press the R
ISO
/250V/500V/1000V key and read the measured
value from the display.
Example
Note
If the minimum permissible limit value is fallen short of,
<1M or < 0.5 M appears for R
ISO
.
9.6 Ground Fault Test
If the test instrument recognizes an inadmissible, low insulation
value during I
SC
/R
ISO
measurement, the instrument tests for pos-
sible ground fault.
If a ground fault occurs within the system, the error can be nar-
rowed down on the basis of the voltage ratio.
Warning!
Disconnect all solar modules from the system before
performing the measurement.
➭ Connect the PROFITEST PV
SUN to the module with the help of
suitable solar plugs.
➭ Connect the ground terminal at the PROFITEST PV
SUN to the
module frame.
➭ Switch the PROFITEST PVSUN test instrument on.
Momentary open circuit voltage is displayed.
At the same time, a second voltage (Ue) appears in the event of a
ground fault.
Example
System Voltage (U0
x 1.25)
Test Voltage Limit Value
< 120 V 250 V 0.5 M
120 to 500 V 500 V 1 M
> 500 V 1000 V 1 M
U
0
: 0 V
I
SC
: 0.0 A
R
ISO
: < 1 M
U
0
: 0 V
I
SC
: 0.0 A
R
ISO
: ---
Uiso = 1000 V
U
0
: 0 V
I
SC
: 0.0 A
R
ISO
: > 20 M
U
0
: 144 V
I
SC
: 0.0 A
Ue: 48 V