Line connection and line-side power components
3.5 Overvoltage protection
Booksize Power Units
Manual, (GH2), 07/2016, 6SL3097-4AC00-0BP8
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To protect the units against line-side surge voltages, install an overvoltage protection device
(surge arrester) directly at the infeed point. For use in Canada, to comply with the
requirements of CSA C22.2 No. 274, a UL category VZCA7 or VZCA8 surge arrester is
absolutely mandatory. The Raycap company has suitable surge arresters.
A line contactor is required if the drive line-up needs to be electrically isolated from the
power supply.
The characteristic values in the technical data apply when the line contactor is selected. The
cables and conductors to be connected must be dimensioned in compliance with local
installation regulations.
Damage to the drive electronics when switching the line contactor under load
When switching the line contactor (type according to the recommended selection) under
load, then the contacts will be subject to premature wear. This can cause the contactor to
malfunction, with subsequent damage to the drive electronics.
• Use a leading opening auxiliary contact or use a Voltage Sensing Module (VSM10).
• If this is not possible, then avoid switching the line contactor under load.
Note
If you are using a VSM10 Voltage Sensing Module, the leading opening contact can be
omitted.
Note
To limit the switching overvoltage, the contactor coil must be connected to a surge
suppression device (e.g. free
-wheeling diode or varistor).
When the digital output is used to control the line contactor, its switching capacity must be
taken into account.