KACO blueplanet 3.0 NX3 M2 KACO blueplanet 5.0 NX3 M2 KACO blueplanet 8.0 NX3 M2 KACO blueplanet 10.0 NX3 M2
KACO blueplanet 15.0 NX3 M2 KACO blueplanet 20.0 NX3 M2
Page 18
7.5.2
Checking the PV generator for a ground fault
DANGER
Risk of fatal injury due to electric shock!
Coming into contact with live connections can cause serious injury or death. When there is sunlight present
on the PV generator, there is DC voltage on the open ends of the DC cables.
› Only touch the PV generator cables on the insulation. Do not touch the exposed ends of the cables.
› Avoid short circuits.
› Do not connect any strings with a ground fault to the device.
NOTE
The threshold value above which the insulation monitor reports an error can be set on the mobile device
under Other protection settings - Minimum insulation resistance.
Ensure that there is no ground fault
1 Measure the DC voltage between the protective earth (PE) and the positive cable of the PV generator.
2 Measure the DC voltage between the protective earth (PE) and the negative cable of the PV generator.
If stable voltages can be measured, there is a ground fault in the DC generator or its wiring. The ratio between the
measured voltages gives an indication as to the location of this error.
3 Rectify any errors before taking further measurements.
4 Measure the electrical resistance between the protective earth (PE) and the positive cable of the PV generator.
5 Measure the electrical resistance between the protective earth (PE) and the negative cable of the PV generator.
In addition, ensure that the PV generator has a total insulation resistance of more than 2.0 MOhm, since the device
will not feed in if the insulation resistance is too low.
6 Rectify any errors before connecting the DC generator.
7.5.3
Recommended standard connection
Fig. 22.
Assignment of both MPP trackers
Fig. 23.
Assignment of only one MPP tracker
Possible connection of MPP trackers PV1 and PV2
Two DC strings for
each
MPP tracker
Two DC strings for
one
MPP tracker
The MPP voltages of the two DC strings can be different.
They are supplied by separate, independently operating
MPP trackers (MPP trackers PV1 and PV2).
If one of the MPP trackers is not used, only the unused DC
connectors need to be closed.
It is irrelevant whether PV1 or PV2 is used.
PV1
U
MP
P
n
1
n
2
n
3
n
4
PV2
