Safety Devices; Anti-Islanding; Ground Fault Of The Photovoltaic Panels; String Fuses - ABB PVS-50-TL Product Manual

S
afety devices
A
nti-Islanding
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
S
tring fuses
The sizing of the fuses must therefore be carefully assessed during installation.
O
vervoltage surge arresters
O
ther safeguards
The numerous control systems determine a redundant structure to ensure absolutely safe
operations.
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
An advanced ground fault protection circuit continuously monitors the
ground connection and disconnects the inverter when a ground fault in-
dicating the fault condition by means of the red "GFI" LED on the LED
panel on the front side (where the accessory is present).
Use this inverter with panels connected in "floating" mode, i.e. with no
earth connections on the positive and negative terminals.
The DC compartment can be equipped with string fuses are:
-SX version - Only positive side (+) string fuses
-SX2 version - Negative side (-) string fuses

string fuses

are preinstalled.
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The fuses protect the appliance from currents exceeding the limit value
independently for each string.
As additional protection to prevent damage caused by lightning and elec-
trostatic induction phenomena, all versions are equipped with type 2 over-
voltage arresters (optional -SX2 version Type I+II on the DC side).
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).
- 44 -
2 - Characteristics
are preinstalled
35
and the positive side (+)
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