In a standstill phase, it can make sense to use the brake


  First condition for choosing of the suitable motor should be an analysis
of the estimated load:


Case 1: Continuous operation
A motor running in continuous operation must transmit its lost heat to the ambience so that the max. coil temperature is not exceeded. In the technical data the current values and corresponding torques are shown for a max. coil temperature of 100°C, water cooling with a cooling temperature of 20°C implied.
The coil temperature is monitored by temperature sensors. For interpretation in the control system a KTY-sensor and a PTC for each motor phase are available. In continuous operation a regular load of all three phases and a regular temperature distribution can be assumed. Because of comparatively slow temperature changing the monitoring of the motor can be achieved with the KTY as well as with the three PTC‘s. To increase operational safety we recommend the interpretation of both sensor types.

  Case 2: Interval operation
In interval operation the value of the surface below the load graph of the motor is important.
The effective torque is calculated with the well known formula as follows:

For the effective current applies accordingly:

Momentary current and torque may reach twice the values of those during continuous operation. The effective values calculated with the formulas shown above must not exceed the values of the continuous current shown in the tables.

Case 3: Peak operation
Round table operation is a typical example for peak operation. Here acceleration and deceleration may increase up to triple continuous torque because between the peaks hardly any power is necessary. Also in this case the effective values must not exceed the values of the continuous operation.
Depending on motor temperature the permanent magnets come into danger of demagnetisation. Therefore similar applications and the choice of the suitable motor should be discussed with our engineers.

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