Siemens SIDOOR AT40 System Manual page 61

permissible tolerance is exceeded, this can indicate a mechanical problem in the slow start or
slow end mechanics.
Motor peak current in the slow start and end distance
• Peak current within the slow start distance in the opening direction
• Peak current within the slow end distance in the closing direction
Peak currents occurring in the slow start or end distance are measured for opening and closing
direction.
If the peak currents increase, this is a sign of mechanical problems, contamination or wear in the
slow start or end mechanics.
Peak currents are only measured for uninterrupted travel. No peak currents are provided during
obstruction, reversing, or braking due to a previous obstruction. The value zero is returned for
the peak currents in this case.
The peak current measurement is carried out in the area of the slow start or end distance:
• In opening direction: 5 mm before the closed position and 10 mm before the end of the slow
start distance.
• In closing direction: 5 mm after the start of the slow start distance and 5 mm before the end
of the slow end distance.
Application example:
After the elevator door has been opened and closed on one floor, the peak power in the slow
start open and slow end close distance for the opening and closing travel can be queried.
If the value zero is read for the currents, this measurement is to be ignored and the travel is to
be repeated.
The measured peak currents can be compared with a reference value. If a permissible tolerance
is exceeded, this can indicate a mechanical problem in the slow start or slow end mechanics.
Mean power dissipation of the motor
The mean motor power dissipation is continuously calculated. This is a measurement for the
thermal load of the motor. If the mean motor power dissipation exceeds the permissible motor
power dissipation, the motor is overloaded or overheated.
Possible causes for an excessive mean motor power dissipation:
• Motor is undersized.
• Increased friction of the travel distance
• High travel cycle number
• Oscillation in the door end positions
After a power failure, the calculation of the average motor power dissipation starts again at zero.
This means that a previous load on the motor is not taken into account.
The time constant for calculating the mean motor power dissipation depends on the motor type
and ranges from 0.5 to 2 hours.
AT40 and ATD400V for elevators
System Manual, 06/2022, A5E42192709-AH
SIDOOR functions
4.3 Extended functions
59