Grid Output Connection (Ac Side); Characteristics And Sizing Of The Protective Grounding Cable; Load Protection Breaker (Ac Disconnect Switch) And Differential Protection Downstream Of The Inverter - ABB PVS-175-TL Quick Installation Manual

Quick Installation Guide - PVS-175-TL "A.1 Version"
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9. Grid output connection (AC side)

The inverter must be connected to a three-phase TN system with the center of the star connected to ground.
To connect the inverter to the grid is necessary to use a three-wire connection (3 phases) without neutral
cable. In any case, the inverter's earth connection is mandatory.

9.1 Characteristics and sizing of the protective grounding cable

ABB inverters must be earthed via the connection points marked with the protective earth
symbol and using a cable with an appropriate conductor cross-section for the maximum
ground fault current that the generating system might experience. According to IEC 62109-1:
If the external Protective earthing conductor cross-section area is S/2, where S is the cross-section of the
phase conductor, no further calculation are needed to demonstrate that the cross-section is enough to
sustain the fault current.
by calculation according to IEC 60364-5-54 or have to fulfill the requirement of local standard.
A ATTENTION –
Any failure of the inverter when it is not connected to earth through the appropriate
connection point is not covered by the warranty.
The ground connection can be made through the Protective earth point (int.) (28), Protective earth point
(ext.) (10) or both (this is required by regulations in force in certain countries of installation).
The sizing of the ground cable depend on the choice of the protective earth point (internal (28) or external
(10)) where it will be connected:
Cable diameter range
Max. conductor cross section
Cable lug dimensioning
9.2 Load protection breaker (AC disconnect switch) and differential
protection downstream of the inverter
To protect the AC connection line of the inverter, an overcurrent protection device with the following
features must be installed (these are the caracteristic of a load protection switch referred to a single inverter
installation):
Load protection breaker requirements
Type
Voltage/current rating
Magnetic protection characteristic
Number of poles
(*): please consider thermal and other derating when selecting the current rating of the protection equipment for your application.
In case of installation of a residual current protection, the device shall meet the following characteristics in
order to prevent nuisance tripping due to capacitive leakage current of photovoltaic modules:
Residual current protection device requirements
Type
Sensitivity
D NOTE –
For protection of the AC line, on the basis of the information above with regard to the
differential protection integrated in ABB inverters, it is not necessary to install a type B ground fault
switch.
Otherwise the protective earthing conductor cross-section shall be determined
Protective earth point (int.) (28)
18 - 25 mm
185 mm² copper
240 mm² aluminium
for M10 Stud
a = 10.5 mm (min)
b = 40 mm (max)
Automatic circuit breaker with
thermal-magnetic protection
800 V / 150 A (*)
Magnetic curve B/C
Protective earth point (ext.) (10)
a = 8.4 mm (min) - 8.5 mm (max)\
3
A / AC
2.0 A
-
-
for M8 Bolt
b = all dimension accepted
Fuses switch disconnector
800 V / 200 A (*)
gG, gS
3