ABB RELION 620 Series Technical Manual page 834

Section 5
Protection related functions
5.5.4
828
overload that can damage the motor. The emergency start-up function ESMGAPC
allows motor start-ups during such emergency conditions. ESMGAPC is only to force
the protection relay to allow the restarting of the motor. After the emergency start
input is activated, the motor can be started normally. ESMGAPC itself does not
actually restart the motor.
The function contains a blocking functionality. It is possible to block function outputs,
timer or the function itself, if desired.
Operation principle
The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "On" and "Off".
The operation of ESMGAPC can be described using a module diagram. All the
modules in the diagram are explained in the next sections.
GUID-18128621-4A78-45D0-A788-9116B5213449 V1 EN
Figure 429: Functional module diagram
Standstill detector
The module detects if the motor is in a standstill condition. The standstill condition
can be detected based on the phase current values. If all three phase currents are below
the set value of Motor standstill A, the motor is considered to be in a standstill
condition.
Timer
The timer is a fixed 10-minute timer that is activated when the ST_EMERG_RQ input
is activated and motor standstill condition is fulfilled. Thus, the activation of the
ST_EMERG_RQ input activates the ST_EMERG_ENA output, provided that the motor
is in a standstill condition. The ST_EMERG_ENA output remains active for 10
minutes or as long as the ST_EMERG_RQ input is high, whichever takes longer.
The activation of the BLOCK input blocks and also resets the timer.
The function also provides the ST_EMERG_ENA output change date and time,
T_ST_EMERG. The information is available in the monitored data view.
1MRS757644 F
620 series
Technical Manual