Lenze 8200 vector Instructions De Montage page 113

Controllers can cause a DC current in the PE conductor. If a residual current device
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(RCD) or a fault current monitoring unit (RCM) is used for protection in the case of
direct or indirect contact, only one RCD/RCM of the following type can be used on
the current supply side:
– Type B for the connection to a three−phase system
– Type A or type B for the connection to a single phase system
Alternatively another protective measure can be used, like for instance isolation from
the environment by means of double or reinforced insulation, or isolation from the
supply system by using a transformer.
If you use the Selection of direction of rotation" function via the digital signal
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DCTRL1−CW/CCW (C0007 = 0 ... 13, C0410/3 ¹ 255):
– In the event of an open circuit or failure of the control voltage, the drive can
change its direction of rotation.
If you use the function "flying restart circuit" (C0142 = 2, 3) for machines with a low
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moment of inertia and low friction:
– After controller enable at standstill, the motor can start for a short time or change
its direction of rotation for a short time.
Device protection
Frequent switching of the supply voltage (e.g. inching mode via mains contactor)
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can overload and destroy the input current limitation of the controller:
– Wait for at least 3 minutes between two starting operations.
Only switch contactors in the motor cable when the controller is inhibited.
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Otherwise ...
– monitoring functions of the controller can be activated.
– the controller can be destroyed under unfavourable operating conditions.
Motor protection
For some controller settings, the connected motor may overheat (e.g. when
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operating the DC injection brake or a self−ventilated motor at low speed for longer
periods).
– Using an overcurrent relay or a temperature monitoring device provides a large
degree of protection against overload.
– We recommend to use PTC thermistors or thermal contacts for motor temperature
monitoring. (Lenze three−phase AC motors are equipped with thermal contacts
(NC contacts) as standard)
– PTC thermistors or thermal contacts can be connected to the controller.
Drives can attain dangerous overspeeds (e.g. setting of high output frequencies with
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motors and machines not qualified for this purpose).
EDK82EV903 DE/EN/FR 5.1
Safety instructions
Residual hazards of Lenze controllers
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