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000964AG
3 - Characteristics
S
afety devices
A
nti-Islanding
In the event of a local grid outage by the electricity company, or when
the equipment is switched off for maintenance operations, the inverter
must be physically disconnected to ensure the protection of the people
working on the grid, in accordance with the relevant national laws and
regulations. To prevent possible islanding, the inverter is equipped with
an automatic safety disconnection system called “Anti-Islanding”.
The method used to ensure an active anti-islanding protection is: active
frequency drift in combination with techniques RoCoF
Anti-islanding protection mechanisms are different depending on the grid standards, even if
they all have the same purpose.
G
round fault of the photovoltaic panels
Use this inverter with panels connected in "floating" mode, i.e. with no earth
connections on the positive and negative terminals. An advanced ground
fault protection circuit continuously monitors the ground connection and
disconnects the inverter when a ground fault indicating the fault condition
by means of the red "GFI" LED on the LED panel on the front side.
S
tring fuses
String fuses are available inside the wiring box (in the -SX, -SY wiring box
version only on positive input side
19
; in the -SX2, -SY2 wiring box version
on both positive
19
and negative
20
input side) and protect the appliance
from currents exceeding the limit value independently for each string.
The sizing of the fuses must therefore be carefully assessed during installation. Refer to the
“Sizing of fuses” chapter of this manual to know how to chose the proper size of fuses.
O
vervoltage surge arresters
As an additional protection to prevent damage caused by the discharges
from lightning and electrostatic induction phenomena, the wiring box is
equipped with DC overvoltage surge arresters
32
and with AC overvoltage
surge arresters
22
.
O
ther safeguards
The inverter is equipped with additional protective devices to ensure safe
operation in any circumstance. These protections include:
- Constant monitoring of the grid voltage to ensure that voltage and fre-
quency values remain within operating limits;
- Internal temperature control to automatically limit the power if necessary to
prevent overheating of the unit (derating).
The numerous control systems determine a redundant structure to ensure absolutely safe
operations.
