26 Planning the electrical installation
Equipping the drive with a main contactor and manual
control switch(es)
It is highly recommended to equip the drive with a main contactor and wire it to fault
indication relay output X3 on the chopper control board. This configuration also requires a
manual start/stop switch(es) for system start-up.
The relay output indicates chopper faults, for example, in a thermal overload situation (see
page 31). The changeover switch opens when a failure is detected or the chopper is
unpowered.
WARNING! In a chopper failure, always switch off the power supply to the drive.
This is the only way to guarantee safe operation in case of a chopper failure since
the chopper is unable to disconnect the resistor from the intermediate circuit.