Operation On A Converter With A Low Pulse Frequency - Siemens 1LA8 Operating Instructions Manual

Electrical connection
6.5 Connecting the auxiliary circuits
6.5.6.1

Operation on a converter with a low pulse frequency

NOTICE
Increased motor temperature
For operation on a converter with a low pulse frequency, increased losses occur in the motor.
This results in a higher motor temperature.
Reduce the power to prevent exceeding the temperature class and to avoid consequential
premature thermal aging of the insulation.
Dangerous voltage via the converter
As long as the feeding converter is switched on, or the DC link of the converter is not
discharged, there can be a voltage at the motor terminals even when the rotor is not moving.
The voltage is up to 1000 V, depending on the converter type.
Ensure that the five safety rules (Page 16) are followed before working on the motor.
6.5.6.2 Converter peak voltage
The values for the maximum converter peak voltage as limit values for the insulation system
are given in the table below:
Table 6-7
Rated converter voltage [V]
≤ 500 V
> 500 to 690 V
NOTICE
Insulation damage caused by cable reflections
Cable reflections can double the voltage load at the motor or at the terminals. This can
damage the insulation system and result in complete destruction of the machine.
80
WARNING
Maximum converter peak voltage
Maximum converter peak voltage Û
Phase-to-phase Phase-to-ground
1500 V
Rise time 0.5 μs Rise time 0.5 μs
2250 V
Rise time 0.4 μs Rise time 0.4 μs
max
DC link
1100 V
1500 V 1125 V
SIMOTICS TN Series N-compact 1LA8
Operating Instructions 05/2014
750 V