Operation; Safety Functions; Setting The Safe State; Objective Of A Safety Function - SMA COMMERCIAL STORAGE SOLUTION 30 System Manual

10 Operation

10 Operation
10.1

Safety Functions

10.1.1 Setting the Safe State

The safe state of the system is always set to Disconnected.
In this state, both contactors are open and the battery is not connected to an inverter or a load. This configuration
guarantees that neither charging or discharging can take place and that the battery is isolated from any external
electrical load.
Continuous monitoring of the contactors and feedback contacts are performed in this state. If a contactor error is
detected, the system remains in an ERROR state and cannot be switched on.

10.1.2 Objective of a Safety Function

A safety function in the context of this installation manual refers to a specific system function that has been specifically
developed to minimize the risks in connection with identified dangers. Its main objective is to quickly recognize and
respond to potentially dangerous situations in order to prevent or reduce harm to people, the environment, or property.

10.1.3 Overview of Safety Functions

Designation
V_String, V_DC_EXT
V_DC_EXT
Bat-Com Slave Count
Battery Current
Battery Module
Bat-Com Time Out
Precharge
Contactor
E-Stop
Parameter valid check
Firmware valid check
CPU diagnostic
VREF2
V_REF_INT
Fault Hardware Logic
RAM
102 ESSX-20-SH-en-10
Description
Plausibility check against V_String voltage
Check of polarity reversal
Comparison of number of detected battery modules and number of
parameterized modules ("greater than" semantics)
Check of I_String1
Check of each connected battery module (Bat-Com) with regard to
cell voltages, temperatures, temperature imbalance in module, and
string/voltage imbalance
Check of Bat-Com communication timeout
Check of time and voltage difference between V_String and
V_DC_EXT during precharging
Plausibility check of auxiliary contacts compared to main contactor
switching condition
Check of whether E-Stop is active
Cyclical redundance check
CRC check
Check of timers, ports, and watchdog, etc.
CRC check
Check of timers, ports, and watchdog, etc.
Internal status signal FLT of hardware safety circuit
Test and check of microcontroller RAM
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