Grid and system protection is switched between a decentralized energy producer, such as a photovoltaic system, for example, and the grid of the public energy supply company (EVU) and continuously checks the grid quality. If the voltage or frequency in the public grid rises or falls beyond permissible limits, the small power station is immediately decoupled. In this way, any unintentional or “potentially dangerous” isolated operations are prevented from being carried out by maintenance personnel.

The new grid and system protection has a wide-ranging power supply with an adjustable nominal voltage of 24 V DC, 110-240 V AC with up to 60 Hz nominal.

FUNCTIONAL SAFETY ON BOARD

The grid and system protection from Tele offers functional safety as a standard. Functional safety means that a single fault in the device may not lead to a loss of the safety functions. To ensure this, all components are implemented in duplicate in the device – every value is measured in parallel on both channels and constantly compared to ensure fault-free operation.
ISOLATED OPERATION DETECTION

The new grid and system protection from Tele offers functionally safe grid monitoring with protection for both voltage and frequency increases and decreases as well as the safe detection of isolated operation. Isolated operation detection is therefore possible in three different ways – phase voltage monitoring, RoCoF (Rate of Change of Frequency), or vector shift. Which of the three processes must be used is defined by the relevant applicable standard. Thus the new RE NA003 Tele grid and system protection covers all possible applications in one device.