Operation On A Converter With A Low Pulse Frequency; Measuring The Insulation Resistance Before Commissioning - Siemens 1LA8 Operating & Installation Instructions Manual

● Any supplementary motor monitoring devices and equipment have been correctly
● In continuous operation, the motor cannot exceed the specified upper speed limit n
7.2.1

Operation on a converter with a low pulse frequency

Risk of explosion as a result of increased motor temperature
If the pulse frequency is less than the rated pulse frequency, then increased motor losses
occur. This results in a higher motor temperature.
An explosion can occur in operation. This can result in death, serious injury or material
damage.
● Observe the data on the machine rating plate.
● Never fall below the minimum pulse frequency. This means that you avoid exceeding the
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.
● The bearing insulation should be implemented as shown on the plates.
7.3

Measuring the insulation resistance before commissioning

Measuring the insulation resistance and polarization index (PI) provides information on the
condition of the machine. It is therefore important to check the insulation resistance and the
polarization index at the following times:
● Before starting up a machine for the first time
● After an extended period in storage or downtime
● Within the scope of maintenance work
SIMOTICS TN Series N-compact 1LA8
Operating Instructions 08/2017
connected and are functioning correctly.
undershoot the lower speed limit n
The permissible acceleration time to the limit speed n
assignment.
WARNING
temperature class, and as a consequence igniting an explosive atmosphere.
WARNING
7.3 Measuring the insulation resistance before commissioning
.
min
depends on the parameter
min
Start-up
or
max
89