Planning the electrical installation
71
Protecting the drive against ground faults
The drive is equipped with an internal ground fault protective function to protect the 
unit against ground faults in the motor and motor cable. This is not a personal safety 
or a fire protection feature. The ground fault protective function can be disabled with 
a parameter, refer to the appropriate Firmware Manual.
Measures for protection in case of direct or indirect contact, such as separation from 
the environment by double or reinforced insulation or isolation from the supply 
system by a transformer, can be applied.
Residual current device compatibility
The drive is suitable to be used with residual current devices of Type B. 
Note: The EMC filter of the drive includes capacitors connected between the main 
circuit and the frame. These capacitors and long motor cables increase the ground 
leakage current and may cause fault current circuit breakers to function. 
Implementing the Emergency stop function
For safety reasons, install the emergency stop devices at each operator control 
station and at other operating stations where emergency stop may be needed. 
Note: Pressing the stop key ( ) on the control panel of the drive does not generate 
an emergency stop of the motor or separate the drive from dangerous potential.
Implementing the Safe Torque Off function
The drive supports the Safe Torque Off function according to standards 
EN 61800-5-2:2007; EN 954-1:1997; IEC/EN 60204-1:1997; EN 61508:2002 and 
EN 1037:1996.
The Safe Torque Off function disables the control voltage of the power 
semiconductors of the drive output stage, thus preventing the inverter from 
generating the voltage required to rotate the motor (see diagram below). By using 
this function, short-time operations (like cleaning) and/or maintenance work on non-
electrical parts of the machinery can be performed without switching off the power 
supply to the drive.