Technical Description; Functional Description; Functions Of The Feeder Terminal; Protection Functions - ABB REF 54 Series Technical Reference Manual, General

1MRS750527-MUM
5.
5.1.
5.1.1.
5.1.1.1.
Table 5.1.1.1-1 Protection functions available for REF 54_
Function ANSI device no. IEC symbol
AR5Func 79
2) 51NC-1
CUB1Cap
3) 51NC-2
CUB3Cap
CUB3Low 46
DEF2Low 67N-1
DEF2High 67N-2
DEF2Inst 67N-3
Feeder Terminal
Technical Reference Manual, General

Technical Description

Functional description

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.
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.
Description
O-->I Auto-reclose function (5 shots)
dI>C Current unbalance protection for shunt capacitor banks
3dI>C Three-phase current unbalance protection for H-bridge connected shunt
capacitor
Iub> Phase discontinuity protection
Io>--> Directional earth-fault protection, low-set stage
Io>>--> Directional earth-fault protection, high-set stage
Io>>>--> Directional earth-fault protection, instantaneous stage
REF 54_
21