Motor Start Up; Rated Current Of The Protected Unit - ABB REM 610 Technical Reference Manual

1MRS755537
5.1.1.6.
5.1.1.7.
Motor Protection Relay
Technical Reference Manual - ANSI Version
The estimated time to the next possible motor start up, i.e. when the restart disable
signal is reset, can be accessed either via the HMI or the SPA bus.
If the restart disable function has been activated (SGF1/7=0), SGR3
will be overridden.

Motor start up

A motor start-up situation is defined by means of the phase currents as follows:
Motor start up begins (the motor start-up signal is activated) when the maximum
*
phase current rises from a value below 0.12 x FLA, i.e. the motor is at standstill,
to a value above 1.5 x FLA within less than 60 ms.
Motor start up ends (the motor start-up signal is reset) when all phase currents
*
fall below 1.25 x FLA and remain below for at least 200 ms.
The start-up time of the latest motor start up can be accessed via the HMI and read
with SPA parameter V3.
The motor start-up signal is routed to the output contacts with the switches of
switchgroups SGR1...SGR5.
All operation targets on the LCD will be cleared when a motor start up
begins.

Rated current of the protected unit

A scaling factor, PU scale, can be set for the phase currents. This will allow
differences between the rated current of the protected unit and that of the energizing
input. Consequently, the rated current of the relay can be set to equal the full load
current (FLA) of the motor. A scaling factor, I
This will allow differences between the rated current of the protected unit and that of
the energizing input. Consequently, the rated current of the relay can be set to equal
the full load current (FLA) of the motor.
The current settings of the protection functions are related to the scaled rated
current, FLA. The measured currents are presented either as primary values or as
multiples of the scaled rated current. The current values in the recorded data are
presented as multiples of the rated current.
The scaling factor affects the operation accuracy of the protection
functions, with the exception of the ground-fault protection. The stated
operation accuracy for each protection function only applies when the
scaling factor is 1.
REM 610 REM 610
, can be set for the phase currents.
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