Characteristics Of The Protective Grounding Cable; Line Cable And Protection Devices - ABB PVS-175-TL Quick Installation Manual

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Characteristics of the protective grounding cable

ABB inverters must be earthed via the connection points marked with the protective earth symbol
propriate conductor cross-section for the maximum ground fault current that the generating system might experience. In any case
the minimum cross sectional area of the protective earthing conductor must be at least 1/2 of phase conductors cross sectional
area.
Any failure of the inverter when it is not connected to earth through the appropriate connection point is not cov-
ered by the warranty.
The ground connection can be made through the Protective earth point (int.) (26), 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 (26) or external (10)) where it will be
connected:
Cable diameter range
Max. conductor cross section
Cable lug dimensioning
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Line cable and protection devices

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):
Type
Nominal Voltage
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 nui-
sance tripping due to capacitive leakage current of photovoltaic modules:
Type
Sensitivity
ABB declares that the ABB transformerless inverters, in terms of their construction, do not inject continuous ground fault currents
and therefore there is no requirement that the differential protection installed downstream of the inverter be type B in accordance
with IEC 60755 / A 2.
Characteristics and sizing of the line cable
Depending of the type of the AC panel it's possible to use single conductors cables or a multipolar cable:
• Single-core configuration have 3xM40 cable glands for the "R", "S", "T" phases and a M32 cable gland (12) for the grounding cable.
• Multi-core configuration (optional) have a M63 cable gland (11) for the "R", "S", "T" phases and a M32 cable gland (12) for the
grounding cable.
The cross-section of the AC line conductor must be sized in order to prevent unwanted disconnections of the inverter from the grid
due to high impedance of the line that connects the inverter to the power supply point.
Cable diameter range
Min. conductor cross section
Cable lug dimensioning
The AC connection busbars (22) are in copper tin-plated; therefore if aluminum cables are used, the correct cou-
pling with the copper bars must be guaranteed by using appropriate bi-metallic cable lug.
Protective earth point (int.) (26)
18 - 25 mm
185 mm² copper / 240 mm² aluminium
for M10 Stud
a = 10.5 mm (min)
b = 40 mm (max)
Load protection breaker requirements
Automatic circuit breaker with thermal-magnetic protection
800 V / 150 A (*)
Magnetic curve B/C
residual current protection device requirements
Single conductor cable
22 - 32 mm
Protective earth point (ext.) (10)
3
A / AC
2.0 A
50 mm²
for M10 Stud
a = 10.5 mm (min)
b = 40 mm (max)
and using a cable with an ap-
-
-
for M8 Stud
a = 8.4 mm (min)
b = all dimension accepted
Fuses switch disconnector
800 V / 200 A (*)
gG, gS
3
Multipolar cable
37 - 53 mm
17