KEB COMBIVERT F6 Instructions For Use Manual - Attention
5.8 Motor connection
5.8.1 General information
• The motor cables must be designed to the maximum continuous current.
• They are valid for 0...100 Hz (up to 300 Hz the cable losses increase by approx.
25% due to the skin effect).
• The IGBT modules cause high-frequency interferences which cause a stronger der-
ivation into the earth potential with increasing motor cable length.
• The consequence is an increase of the cable-based interferences on the line side.
•
If the motor cables are too long, the damping of the mains filter is no longer sufficient
and the permitted interference limits are exceeded.
• At the output of the drive converter, pulses with approx. 1.35-fold of the mains volt-
age and very short rise times are generated independently of the output frequency.
• This is the case for all drive converters with modern IGBT drive converter technology.
• The voltage of the pulses can be almost double at the motor terminals, depending
on the motor cable properties.
• This can lead to additional load on the motor and motor cable insulation.
• Modern speed-controlled drives with its rapidly rising voltage pulses and high switch-
ing frequencies can cause current pulses which run through the motor bearings and
lead to a gradual damage of the bearing raceways.
ATTENTION
Protect motor against voltage peaks !
►
The connecting-up instructions of the motor manufacturer are al-
ways generally valid !
►
Inverter switch at the output with high voltage rise speed see „Tech-
nical Data“. Voltage peaks that endanger the insulation system at
the motor can occur especially in case of long motor cables (> 15
m). A motor choke, a du/dt filter as well as a sine-wave filter can be
used to protect the motor.
5.8.2 connection motor cable
ATTENTION
By default, all 690 V motors are connect in star connection.
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eLecTrIcAL INSTALLATION