Line Contactors - Siemens S120 Manual

3.6

Line contactors

A line contactor is required if the drive line-up needs to be electrically isolated from the
power supply.
When selecting a line contactor, the characteristic values in the technical data apply. The
cable routing, the bundling factor, and the factor for the ambient temperature according to
EN 60204-1 must be taken into account when dimensioning the various cables.
NOTICE
Damage to the drive electronics when switching the line contactor under load
If you switch the line contactor (recommended type) under load, the contacts will wear out
prematurely. This may lead to faulty functioning of the contactor with subsequent damage
to the drive electronics.
• Use a leading auxiliary break contactor and/or use a Voltage Sensing Module (VSM10).
• If this is not possible, avoid switching the line contactor under load.
Note
To limit the switching overvoltage, the contactor coil must be connected to a surge
suppression device (e.g. freewheeling diode or varistor).
When a digital output is used to control the line contactor, its switching capacity must be
taken into account.
AC Drive
Manual, (GH6), 04/2014, 6SL3097-4AL00-0BP4
Mains connection and line-side power components
3.6 Line contactors
43