Siemens SINUMERIK 840C - Manual (Page 527)

7 Drive Machine Data (SIMODRIVE Drive MD) 07.97
7.3.2 Drive MD (data description)
2nd power limit value 1236
Default value Lower input limit Upper input limit Units
100.0 5.0 100.0 %
Active
at once
The 2nd power limit value entered in MD 1236 acts as a reduction factor referred to the 1st
power limit value (MD 1235). It becomes active only if the 2nd torque limit value is selected via
the PLC control word and the motor speed exceeds the value set in MD 1232 (Switching
speed from M
d1
to M
d2
) with hysteresis (MD 1234).
Generative maximum output 1237
Default value Lower input limit Upper input limit Units
100.0
0.3
0.1 (as from SW 6)
500.0 kW
Active
at once
Input of generative maximum output. This machine data allows the regenerative energy fed
back via the infeed/regenerative feedback module to be limited. If an uncontrolled infeed/
regenerative feedback module is used, it is particularly important to set this machine data to an
appropriately low value.
Current limit value 1238
Default value Lower input limit Upper input limit Units
150.0 0.0 400.0 %
Active
at once
Input of maximum permissible motor current referred to the motor rated current. In order to
shorten the ramp-up times, it may be advisable to set the current limit to values higher than
100 % and to increase the power and torque limits (MD 1230, MD 1239) at the same time.
Note:
This machine data is relevant only for main spindle drives.
Caution:
Overloading of the motor for long periods may lead to an inadmissibly high temperature rise
(shutdown on motor overtemperature) and even cause irreparable damage to the motor.
Torque limit setup mode 1239
Default value Lower input limit Upper input limit Units
1.0 0.5 100.0 %
Active
at once
Input of torque limit value in set-up mode referred to the motor rated torque. Machine data
1239 is not active in normal operation. In set-up mode, the torque limit applied is based on the
minimum value calculated from the limits for normal operation and the value set in this
machine data (see diagram for MD 1230). Set-up mode is selected by means of terminal 112
on the infeed/regenerative feedback module.
7–112 © Siemens AG 1992 All Rights Reserved 6FC5197- AA50
SINUMERIK 840C (IA)