Integrated relay protection device relay REF615

Functions of the feeder terminal The functions of the REF 54_ feeder terminal are categorized as:

• Protection functions

• Measurement functions

• Power quality functions

• Control functions

• Condition monitoring functions

• Communication functions

• General functions

• Standard functions The functions are further divided to three subsets that correspond to different functionality levels (refer to Section “Ordering Information” on page 103). All function blocks are documented on the CD-ROM “Technical Descriptions of Functions”, refer to Section “Related documents” on page 10 for more information.

The function blocks of the terminal are listed in Tables 5.1.1.1-1 to 5.1.1.8-1,. If the ANSI device no. and IEC symbol columns are missing from a table, the function block uses the same symbol in the ANSI and IEC modes as stated in the Function column. 5.1.1.1. Protection functions Protection is one of the most important functions of the REF 54_ feeder terminal. The protection function blocks (for example NOC3Low) are independent of each other and have their own setting groups and data recording.

The non-directional overcurrent protection includes the three stages NOC3Low, NOC3High and NOC3Inst, each with independent protection functions. Either Rogowski coils or conventional current transformers can be used for protection functions based on current measurement. Correspondingly, voltage dividers or voltage transformers are used for protection functions based on voltage measurement.