Lenze 13.7xx Motors-Geared motors - Manual (Page 16)

Safety instructions
Safety instructions for low−voltage machines
2
l
16 BA 13.0009 − EN 2.1
Operation on the frequency inverter for AC motors
The label in the terminal box specifies the limit values of the voltages with which the
isolation system of the motor may permanently be loaded. Example of product series
13.7
LL.
Permissible voltage:
û v 0.75 kV
du / dt v 5 kV / ms
Protection of the motor against impermissible voltage peaks
ƒ During operation of the motors on the frequency inverter or during switching
operations on the mains, voltage peaks that may damage the motor isolation can
occur.
ƒ In order to avoid malfunctions, the limit values specified in the table may not be
exceeded:
Application of the motor on Limit values for voltage peaks
max. amplitude û (kV)
max. rate of rise
du / dt (kV / ms)
Frequency inverter, single−phase 0.75
5 Frequency inverter, three−phase 1.5
Mains (switching operation) 0.75
)
Note!
For switching operations on the mains you can limit the voltage peaks by
means of a suppressor circuit with RC elements or varistors (not included in
the scope of supply).
Dimension the suppressor circuit for the respective application case!