Application - ABB RELION REX640 Technical Manual

1MRS759142 C
6.7.5
6.7.6
REX640
Technical Manual
PCM600. Similarly, the TEMP_RL output of MPTTR must be connected to the
TEMP_RL input of this function in Application Configuration in PCM600.
When the emergency start signal START_EMERG is set high and if the value of the
cold or warm counter is above its start value setting, the value of the counter is set one
count less than the respective maximum number of start value setting. This disables
BLK_RESTART and OPERATE which makes the restart of motor possible.
The values can be reset by activating the RESET binary input. The activation of the
RESET input also resets the counter decrease timer. The counter value can also be
reset on the Clear menu.
Limit supervision
This module compares the motor cold and warm count to the set Max Num cold start
and Max Num warm start, respectively. The BLK_RESTART output is activated when
either the cold or the warm start counter reaches the set Max Num cold start or Max
Num warm start, respectively. The OPERATE output is activated when either the cold
or the warm start counter exceeds the set Max Num cold start or Max Num warm
start, respectively.
When the BLK_RESTART output is active, T_RST_ENA shows the possible time for
the next restart. The value of T_RST_ENA is calculated as the time left for both
counters to decrease below their maximum number of starts.
Activation of the BLOCK input blocks both OPERATE and BLK_RESTART outputs.

Application

Repeated motor starts increase the temperature to a high value in the stator or rotor
windings, or both, unless enough time is allowed for the heat to dissipate. To ensure
a safe operation, it is necessary to provide a fixed-time interval between starts or limit
the number of starts within a period of time. This is why the motor manufacturers have
restrictions on how many starts are allowed in a defined time interval.
This function counts the number of cold and warm starts and provides a block restart
signal when the number of starts reaches the permitted limit. The customer can use this
signal for blocking a new start operation. An operate signal is also available which can
be used to disconnect the motor when the number of starts exceeds the limit.
Signals
Table 1171: MSCPMRI Input signals
Name Type
BLOCK BOOLEAN
START_EMERG BOOLEAN
RESET BOOLEAN
MOT_RUN BOOLEAN
TEMP_RL FLOAT32
Supervision functions
Default Description
0=False Block signal for activating the blocking mode
0=False Signal to indicate the need of emergency start
0=False Reset cold and warm start counter value
0=False Signal to show that motor start up is in progress
0.00 Thermal level of the motor
Section 6
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