Manual

3 Product Overview
SMA Solar Technology AG
User ManualSBxx-US-1XP-41-BA-en-1018
A complete PV Rapid Shutdown System consists of the inverter, PV array disconnect switches, and a
Rapid Shutdown initiation device. The Rapid Shutdown initiation device serves to initiate a rapid
shutdown. The PV Rapid Shutdown System must limit the DC conductors to <30V within
30seconds.
NOTICE - The inverter's Rapid Shutdown function is initiated by disconnecting the inverter from the
AC grid voltage, for example, by opening the main PV system AC disconnect. The AC disconnect
that serves as the Rapid Shutdown initiation device must be readily accessible and clearly marked
in accordance with National Electrical Code
®
. The Rapid Shutdown status of the PV system will be
indicated by the On/Off (Closed/Open) position of this AC disconnect. The Off (Open) position
indicates that a rapid shutdown has been initiated.
If PV array disconnect switches compliant with the SunSpec communication signal for Rapid
Shutdown systems are installed, the inverter can transmit a SunSpec-compliant "permission to
operate" signal to them via its DC input conductors. When a rapid shutdown is initiated, the inverter
will stop transmitting the SunSpec signal. When the SunSpec signal is not being received, the PV
array disconnect switches are responsible for reducing line voltages within the PV array in
accordance with National Electrical Code
®
. In the event of a rapid shutdown via the SunSpec
communication signal, it is important that all PV modules connected to the inverter are always
equipped with SunSpec-compliant PV array disconnect switches, otherwise the inverter cannot start
feed-in operation. The sum of the standby voltages of all PV array disconnect switches of a string
must be <30V to ensure safe discharging of the DC lines. In addition, the recommended total
length of all DC lines of a string should not exceed 300m (1000ft). The total length defines the
length of the entire string wiring including the connection cable of the PV module switch in the string
(measured from the positive DC terminal to the negative DC terminal of the inverter).
A PV Rapid Shutdown system can also be installed using PV array disconnect switches initiated in
case of power failures or other means. In these cases, it must be ensured that the PV system Rapid
Shutdown initiation device initiates a rapid shutdown of the PV array devices at the same time that
the inverter is disconnected from grid voltage.
The PV array disconnect switches must disconnect the PV array from the inverter within a maximum
of 15 seconds after Rapid Shutdown initiation.
The inverter is capable of grid support operation where in case of a power failure or by activating
the AC disconnect, the inverter remains connected to the utility grid for a defined ride-through time
and waits for voltage recovery. If grid voltage does not recover within the defined ride-through
time, the inverter disconnects from the grid and a rapid shutdown is initiated.
The Rapid Shutdown function is disabled by default. The Rapid Shutdown function should only be
enabled when PV array disconnect switches have been installed within the PV array or between the
PV array and the inverter. The Rapid Shutdown function can be enabled during or after inverter
commissioning via the user interface by selecting the operating mode suitable for the PV array
disconnect switches. If the Rapid Shutdown function is enabled and no PV array disconnect
switches are installed, the inverter cannot discharge the connected DC input conductors during a
rapid shutdown. As a result, the inverter can be damaged.
WARNING - THIS PV RAPID SHUTDOWN EQUIPMENT DOES NOT PERFORM ALL OF THE
FUNCTIONS OF A COMPLETE PV RAPID SHUTDOWN SYSTEM. THIS PV RAPID SHUTDOWN
EQUIPMENT MUST BE INSTALLED WITH OTHER EQUIPMENT TO FORM A COMPLETE PV
RAPID SHUTDOWN SYSTEM THAT MEETS THE REQUIREMENTS OF NEC (NFPA 70) FOR