GB - 22
Safety Function STO
3.5 Functional Description
TheCOMBIVERTwithintegratedsafetyfunctionmeetsthefollowingfunctionaccordingto
IEC61800-5-2:
• „Safetorqueoff“(SafeTorqueOff–STO)
Thesafety-relateddisconnectionaccordingtoSTOisreachedbyatwo-cannelopto-coupler
blockage. The supply of the opto-couplers, which are responsible for the commutation of the
connected drive occurs via transformation coupling of the input voltage. This ensures at input
voltage loss that no supply of the opto-couplers is possible. If the opto-couplers are not longer
supplied, no IGBT can be controlled and thus no energy can be supplied to the drive.
ThetwochannelsarereachedbywaythatinputSTO1preventsthevoltagesupply(VTRO)
oftheupperopto-couplersoftheinverterbridge andinputSTO2theloweropto-couplers
(VTRU).
TechnicaldataoftheSTOfunction
MaximumONdelay(U
IN=15V) 7 ms
MaximumOFFdelay(U
IN=30V)at
…activemodulation 10 ms
…inactivemodulationuntilsafestateofthedrivervoltageisreached 50 ms