Siemens simovert masterdrives

12.2010 Configuration and Connection Examples
Siemens AG 6SE7087-6QX70 (Version AM)
SIMOVERT MASTERDRIVES Compendium Motion Control 2-21
Fig. 2-7 Schematic diagram of MASTERDRIVES Compact PLUS converter with
K80 board
The power section controls the power feed to the individual motor
windings. The control logic on the control board drives the 6 power
transistors in a particular pattern in order to generate a rotating field. In
order to provide electrical isolation, an optocoupler or fiber optic cable
is connected between the control logic and each control amplifier of a
power transistor. The power supply PV of the optocouplers or fiber optic
cable transmitters is supplied via the NO contact of safety relay K1.
When the "Safe Torque Off" function is active, the NO contact of the
safety relay is open and the NC contact (= checkback contact) is
closed. Because the NO and NC contacts are positively driven, it is
possible to evaluate the status of the safety relay (NO contact) from the
checkback contact (NC contact).
If the "Safe Torque Off" function is active, the NO contacts are open
and the power supply to the optocouplers or fiber optic cable
transmitters is interrupted.
The "Safe Torque Off" function does not isolate the drive from the
supply system. It does not therefore provide any protection against
electric shock.