CG Emotron OSTO 100, Instruction Manual

Page: 18 / 112

18 Functional description CG Drives & Automation 01-7513-11r0
and whereas the gate driver will become powerless when any of the two STO-
inputs goes low (achieving a safe state).
The output signal STO_STATUS_ISO will not be affected by OSSD-test
pulses for test pulses ≤ 1 ms in length (filtered in hardware).
To properly activate STO safety function, both inputs STO1 and STO2 must be
switched off. During normal operation both inputs are switched off at the same
time (synchronized), but it is enough that one channel goes low to activate safe
state. After a response time of ≤ 15 ms has elapsed from one or both input
signals going low, the gate driver will become de-energized and thereby the
motor cannot generate any further torque.
WARNING!
When safe torque off is active, the motor will become torque
free. This means that any hanging/suspended or tensioned load
like e.g. cranes or hoists will require additional brakes or
mechanical interlocks to avoid residual risk of dropping loads.
Dropping loads may cause personal injury or property damage!
Further, make sure that no other residual risk can occur while
the motor is coasting down to zero speed.
DANGER!
The safety function “Safe torque off” (STO) must not be
mistaken for safety function “Emergency off” which also
ensures that the motor is electrically disconnected. Safety
function “Emergency off” requires additional equipment like a
mains switch with undervoltage coil to also achieve electrical
isolation.
WARNING!
Safety function STO must never be used for electrical
maintenance purposes. Before carrying out any electrical
maintenance, the AC drive must always be disconnected from
the power supply.