ABB PVS-175-TL-US, Quick Installation Manual, Page: 27 / 44

25
EN
Load protection breaker (AC disconnect switch) and differential protection downstream of the inverter
To reduce the risk of fire, connect only to a circuit provided with an overcurrent protection in accordance with the NEC (ANSI/NFPA
70). The inverter must be connected only to a dedicated branch circuit provided with the maximum branch overcurrent protection
device (OCPD):
PVS-166-TL-US PVS-175-TL-US
Type Automatic circuit breaker with thermal-magnetic protection
Nominal Voltage /Current 800 Vac / 150 A (*)
Magnetic protection characteristic Magnetic curve B/C
Number of poles 3
(*): please consider thermal and other derating when selecting the current rating of the protection equipment for your application.
• It is installer's responsibility to provide external disconnect switches and OCPD as required by NEC and other prevailing regulations.
• The inverter is designed without an isolation transformer and must be installed per NFPA 70, 690.35 with an ungrounded PV array.
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:
PVS-166-TL-US PVS-175-TL-US
Type A / AC
Sensitivity 2.0 A
ABB declares that the ABB transformerless inverters, in terms of their construction, do not inject continuous earth 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 of the protective grounding cable
Size the cable(s) in accordance with NEC and any local codes.
The wire must be large enough to handle the maximum ground fault current that the PV system might experience.
The warranty is void if the inverter isn’t connected to ground through the appropriate terminals.
Follow site wiring diagrams and grounding plans. At a minimum expect this to include:
• A PV array equipment ground conductor (EGC), to be landed on the EGC connection point (10) located on the external side of the
inverter.
• A protective earth (PE) conductor, to be landed on the protective earth connection point (55) .
Protective earth point (ext.) (10) Protective earth connection point (55)
Cable lug dimensioning
b a
for M8 Bolt
a = 8.4 mm / 0.33" (min)
b = all dimension accepted
for M10 Stud
a = 10.5 mm / 0.42" (min)
b = 40mm / 1.57 (max)
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Installation planning
Characteristics and sizing of the line cable
The cross-section of the AC line conductor cables 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; If the impedance is too high it causes an increase
in the AC voltage which, on reaching the limit set by the standards in the country of installation, causes the inverter to switch off.
The minimum required cross sectional area for the phases conductors is 50mm
2
/ (1/0)AWG.
The AC cables must be connected to the AC connection busbars
(22)
using a cable lug (not supplied) of a suitable size for installation on
the M10 threaded studs used for securing the cable.
Single core cable Multi-core cable
Cable lug dimensioning
b a
for M10 Stud
a = 10.5 mm / 0.42" (min)
b = 40mm / 1.57 (max)
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.