ABB REU615 Voltage protection and control

REF611 is a dedicated feeder protection relay designed for the protection, control, 

measurement and supervision of utility substations and industrial power systems.

The feeder protection relay REF611 can be supplied either with directional or non-directional overcurrent and earth-fault protection. 

Directional earth-fault protection is mainly used in isolated neutral or compensated networks, 

whereas the non-directional earth fault protection is intended for directly or low-impedance earthed neutral networks.

REF611 is a member of ABB’s Relion® product family and part of its 611 protection and control series of relays.

Protection functions

The IED offers directional and non-directional overcurrent and thermal overload protection as

well as directional and non-directional earth-fault protection. 

Some standard configurations allow as an option admittance-based, harmonics-based or wattmetric-based earth-fault protection to be

used in addition to directional earth-fault protection. 

Further, the IED features sensitive earth-fault protection, phase discontinuity protection, transient/intermittent earth-fault protection, 

overvoltage and undervoltage protection, residual overvoltage protection, positive-sequence undervoltage 

and negativesequence overvoltage protection. 

The outstanding I/O capability in REC670 enables control of several bays with complete measurement with only one IED. 

For instance, one REC670 IED is capable of handling control of all apparatuses 

in one entire diameter in 1 ½ breaker arrangement including breaker failure protection for all breakers.

Document conventions

A particular convention may not be used in this manual.

• Abbreviations and acronyms in this manual are spelled out in the glossary. The

glossary also contains definitions of important terms.

• Push-button navigation in the LHMI menu structure is presented by using the push-button icons.

To navigate between the options, use and .

• HMI menu paths are presented in bold.

Select Main menu/Settings.

• LHMI messages are shown in Courier font.

To save the changes in non-volatile memory, select Yes and press .

• Parameter names are shown in italics.

The function can be enabled and disabled with the Operation setting.

• Parameter values are indicated with quotation marks.

The corresponding parameter values are "On" and "Off".

• IED input/output messages and monitored data names are shown in Courier font.

When the function starts, the START output is set to TRUE.