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NRG 26-61 - Installation & Operating Manual -
819874-00
Specialist terms/Abbreviations
Here, we explain some abbreviations, specialist terms, etc., which are used in this Manual.
IEC 61508
International standard IEC 61508 describes both the type of risk assessment and actions taken to provide
appropriate safety functions.
SIL (safety integrity level)
Safety integrity levels SIL 1 to 4 are used to quantify risk reduction. SIL 4 is the highest level of risk
reduction. International standard IEC 61508 forms the basis for establishing, testing and operating
technical safety systems.
CAN (Controller Area Network) bus
Data transmission standard and interface for connecting electronic equipment, sensors and control
systems. Data can be sent and received.
NRG .. / URS .. / URB .. / SRL .. / etc.
Equipment and type designations of GESTRA AG, see page 10.
SELV
Safety Extra Low Voltage
Operating point (of the plant)
The operating point describes the operating parameters within which a plant or boiler is operated in its
nominal range. In a pressurised steam plant, for example, these parameters would be output, pressure
and temperature.
The design data may be a lot more stringent, however.
A boiler that is operated at 10 bar and 180°C may be designed for a pressure of 60 bar and a
temperature of 275 °C, for example, which is not necessarily its operating point.