ABB 615 Series ANSI, Техническое руководство, Страница: 472 / 713

1MAC050144-MB C
Section 6
Supervision functions
615 series ANSI 465
Technical Manual
Stall protection
This module is activated only when the selected Operation mode setting value is “IIt &
stall” or “IIt & stall, CB”.
The startup current is specific to each motor and depends on the startup method used, like
direct on-line, autotransformer and rotor resistance insertion, and so on. The startup time
is dependent of the load connected to the motor.
Based on the motor characteristics supplied by the manufacturer, this module is required
if the stalling time is shorter than or too close to the starting time. In such cases, a speed
switch must be used to indicate whether a motor is accelerating during startup or not.
At motor standstill, the
STALL_IND
input is active. It indicates that the motor is not
running. When the motor is started, at certain revolution the
STALL_IND
input is
deactivated by the speed switch that indicates the motor is running. If the input is not
deactivated within
Lock rotor time , the
OPR_STALL
output is activated.
The module calculates the duration of the motor in stalling condition, the
STALL_RL
output indicating the percent ratio of the start situation and the set value of Lock rotor time .
The value is available through the monitored data view.
The
BLOCK
input signal is used to block the operation of the
OPR_STALL
output. The
activation of the
BLOCK
input resets the operate timer.
Cumulative startup protection
This module protects the motor from an excessive number of startups.
Whenever the motor is started, the latest value of
START_TIME
is added to the existing
value of
T_ST_CNT
and the updated cumulative startup time is available at
T_ST_CNT
.
If the value of
T_ST_CNT
is greater than the value of Cumulative time Lim , the
LOCK_START
output, that is, the lockout condition for the restart of motor, is enabled.
The
LOCK_START
output remains high until the
T_ST_CNT
value reduces to a value less
than the value of Cumulative time Lim . The start time counter reduces at the rate of the
value of Counter Red rate .
The
LOCK_START
output becomes activated at the start of
MOT_START
. The output
remains active for a period of Restart inhibit time .