Lenze 8400 motec - Manual (Page 81)

Lenze · 8400 motec · Reference manual · DMS 4.1 EN · 08/2013 · TD05 81
5 Motor control (MCTRL)
5.1 Special features of the 8400 motec
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
5.1 Special features of the 8400 motec
In contrast to other Lenze inverters, the 8400 motec controller has a reduced DC-bus capacity. This
causes some special features which the user must consider.
The closed design of the 8400 motec controller and the heat input of the motor increase the internal
temperature. However, the use of film capacitors in the DC bus ensures a high service life.
The used capacitors have a lower capacity. This causes the following:
• Less energy can be stored in the DC bus.
• The DC-bus voltage increases faster during braking operation.
• The DC-bus voltage has a higher voltage ripple.
• The medium DC-bus voltage is slightly reduced.
• The controller cannot be connected to the 1-phase mains.
• The oscillation damping in
C00234 has to be adapted if the machine is not under load.
The voltage ripple in the DC bus must not be transmitted to the motor. Otherwise a varying torque
would be caused. The compensation of the voltage ripple causes the maximum motor voltage to
only reach 88 % of the mains voltage (see also display of the motor voltage in C00052 ).
The reduced energy absorption of the DC bus may cause special measures to be taken for braking
loads. This can concern e.g. the use of an external brake resistor or the choice of a larger deceleration
time.