2 Safety
2.1 Appropriate Usage
The X3 Series are PV inverters which can convert the DC current of the PV
generator into AC current and feed it into the public grid.
Surge protection devices (SPDs) for PV installation
Over-voltage protection with surge arresters should be provided
when the PV power system is installed.
The grid connected inverter is fitted with SPDs in both PV
input side and MAINS side.
WARNING
!
Induced surges are the most likely cause of lightning damage in majority or installations,
especially in rural areas where electricity is usually provided by long overhead lines.
Surge may be included on both the PV array conduction and the AC cables
leading to the building.
Specialists in lightning protection should be consulted during the end use application.
Using appropriate external lightning protection, the effect of a direct lightning
strike into a building can be mitigated in a controlled way, and the lightning
current can be discharged into the ground.
Installation of SPDs to protect the inverter against mechanical damage and
excessive stress include a surge arrester in case of a building with external
lightning protection system (LPS) when separation distance is kept.
To protect the DC system, Surge Protection Device(SPD type2) should be fitted
at the inverter end of the DC cabling and at the array located between the
inverter and the PV generator, if the voltage protection level (VP) of the surge
arresters is greater than 1100V, an additional SPD type 3 required surge protection
for electrical devices.
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05
04
Safety
Safety
Anti-Islanding Effect
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Islanding effect is a special phenomenon that grid-connected PV
system still supply power to the nearby grid when the voltage loss
happened in the power system. It is dangerous for maintenance
personnel and the public.
X3 series provide Active Frequency Drift(AFD) to prevent islanding
effect.
1
A
Distribution
Box
Distribution
Box
Inverter
figure1
Lightning will cause a damage either from a direct strike or from surges due to a
nearby strike.
To protect the AC system, surge suppression devices (SPD type2) should be
fitted at the main incoming point of AC supply (at the consumer’s cutout),
located between the inverter and the meter/distribution system; SPD (test
impulse D1) for signal line according to EN 61632-1.
All DC cables should be installed to provide as short a run as possible, positive
and negative cables of the string or main DC supply should be bundled
together. Avoiding the creation of loops in the system. This requirement for
short runs and bundling includes any associated earth bundling conductors.
Spark gap devices are not suitable to be used in DC circuits once conducting,
they won’t stop conducting until the voltage across their terminals is typically
more than 30 volts.
