Siemens 1MB115 Installation And Maintenance Manual page 116

NOTICE
Thermal overload of motors connected directly to the line supply
In addition to the load torque, the ramp-up (accelerating) time is
essentially influenced by the moment of inertia to be accelerated. While
ramping up when connected to the line supply, the inrush (starting)
current is a multiple of the rated current. This can result in thermal
overload. This can damage the motor.
As a consequence, when ramping up, observe the following:
• Monitor the ramp-up time and number of consecutive starts.
• Comply with the limit values and/or ramp-up conditions specified in the
4. During the test run, check and document the following:
5. In case of uneven running or abnormal noise, switch off the machine.
NOTICE
Serious damage to the machine
If the vibration values in operation are not maintained in accordance with
DIN ISO 10816-3, then the machine can be mechanically destroyed.
• During operation, observe the vibration values in accordance with DIN
116
catalog or the order documentation.
– Check whether it is running smoothly.
– Document the voltage, current and power values. As far as possible,
document the corresponding values of the driven machine.
– If this is possible using the available measuring equipment, check the
bearing and stator winding temperatures until they have reached steady-
state values.
– Check the machine for noise or vibrations on the bearings or bearing
shields as it runs.
As the machine runs down, identify the cause.
– If the mechanical operation improves immediately after the machine is
switched off, then the cause is magnetic or electrical.
– If the mechanical running does not improve immediately after switching
the machine off, then the cause is mechanical.
- Imbalance of the electrical machine or the driven machine
- The machine set has not been adequately aligned
- The machine is being operated at the system resonance point. System
= motor, base frame, foundation, ...
ISO 10816-3.