ABB RED521 1MRK002003-BA Voltage Protection Device

The REM 545 machine terminals are used as the main protection system of generator and 

generator-transformer units in small and medium-power diesel, hydroelectric and steam power plants. 

The protection for large and/or important MV synchronous and asynchronous motors used, 

for example, in pumps, mills and crushers during start-up and normal run forms another application area.

The protection functions of REM 545 are designed for selective short-circuit and earth-fault protection of rotating machines. 

Unlike most other power system components, rotating machines also need protection against abnormal 

operating conditions such as over-current, unbalanced load, over-temperature, over-voltage, over and under-excitation, 

under-impedance, over- and under-frequency and generator motoring. 

For motor protection start-up supervision, there are also stall protection and cumulative start-up counter features.

Protection is one of the most important functions of the machine terminal. The

protection function blocks (e.g. NOC3Low) are independent of each other and have

their own setting groups, data recording, etc. The non-directional overcurrent

protection, for example, 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 (overcurrent). Correspondingly,

voltage dividers or voltage transformers are used for protection functions based on

voltage measurement (overvoltage).

The functions are further divided to two subsets that correspond to different functionality levels.

Document conventions

A particular convention may not be used in this manual.

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

contains definitions of important terms.

• 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".

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

The installation manual contains instructions on how to install the mounting assembly

with pre-wired terminals. The manual provides procedures for mechanical and electrical installation. 

The chapters are organized in chronological order in which REX521RRP should be installed.

Cutting tool safety guide contains safety recommendations to the user.

Cutting tool operating guide illustrates how the cutting tool is prepared for operation.

The guide contains instructions on how to operate the tool during relay retrofit.