EN
43
3.13 Safety devices
3.13.1 Anti-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”.
NOTE –
D
The method used to ensure an active anti-islanding protection is: active frequency drift in combination with RoCoF
techniques.
NOTE –
D
Anti-islanding protection mechanisms are different depending on the grid standards, even if they all have the same
purpose.
3.13.2 Ground fault of the photovoltaic panels
ATTENTION –
A
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 LEDs panel
(08)
on the front side of wiring box.
3.13.3 Overvoltage surge arresters
As an additional protection to prevent damage caused by the discharges from lightning and electrostatic induction phenomena, this
inverter is equipped with DC over-voltage surge arresters
(19)
(53)
and with AC over-voltage surge arresters
(22)
.
3.13.4 String 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.
NOTE –
D
The sizing of the fuses must therefore be carefully assessed during installation. Refer to the
paragraph
of this manual to know how to chose the proper size of fuses.
WARNING –
B
Standard and S2 version of the Wiring Box doesn’t assemble fuses inside, and therefore fuses should be accordingly
installed in the external string combiner box.
3.13.5 Other safeguards
This 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 frequency values remain within operating limits;
Internal temperature control to automatically limit the power (if necessary) to prevent overheating of the unit (derating).
NOTE –
D
The numerous control systems determine a redundant structure to ensure absolutely safe operations.
