3 Product Description
SMA Solar Technology AG
20
SCCP-JP-BA-A4-en-12
User Manual
3.4 Sunny Central String-Monitor Controller
Depending on the order option, the Sunny Central may be equipped with a Sunny Central String-Monitor Controller for
string-current monitoring. This controller allows communication between the Sunny Central String-Monitors and the
Sunny Central.
Figure 5: Sunny Central String-Monitor Controller
The Sunny String-Monitors measure the string currents via an integrated measurement PCB and continuously calculate the
mean values of the string currents. The measurement PCB compares the string currents with the mean values. If a string
current exceeds or falls short of the specified tolerance for the mean value, a warning or error is generated and displayed
on the touch display and on the user interface.
3.5 Remote Shutdown
By means of remote shutdown, you can selectively shut down and switch off the Sunny Central within approximately
six seconds, for example, from a control room. The function of the remote shutdown is similar to the stop function of the
key switch.
If the remote shutdown function is activated from the control room while the Sunny Central is in the operating state
"Grid monitoring", a motor drive automatically shuts off the DC switchgear and the Sunny Central switches to the
operating state "Stop".
If the remote shutdown function is activated from the control room while the Sunny Central is in the operating state
"MPP load operation", the Sunny Central switches to the operating state "Shutdown". Once the shutdown is complete,
the AC contactor and the DC switchgear are switched off automatically and the Sunny Central switches to the operating
state "Stop".
The remote shutdown function is designed as an open-circuit fail-safe system and must be operated with an external 24 V
voltage supply.
If 24 V is present in the remote shutdown, the Sunny Central continues to operate in the current operating state. If the
remote shutdown function is triggered or if a wire-break occurs, 0 V is present in the remote shutdown and the
Sunny Central switches from its current operating state to the operating state "Stop".
Use of the remote shutdown will only be possible if the parameter
ExlStrStpEna
is set to
On
.
