Safety Integrated - Industry - Siemens

Behavior when Emergency Stop is issued
Emergency Stop is initiated using button S3 ("Emergency
Stop"). This initiates that the drive is shut down according to
stop Category 1 in compliance with EN 60204-1.
■ A 0 signal is entered at contact 65 (controller enable) of the
drive via the enable contacts of safety combination A1. The
drive is immediately braked down to 0 speed and the pulses
are cancelled.
■ If the drive is stationary (speed = 0), then PLC output DO2
to the internal safety relay of the drive is reset. The internal
safety relay of the drive drops-out and its checkback signal
contacts AS 1/2 close (1st shutdown path!).
Behavior when the protective doors are opened
Button S2 ("Off") requests that the protective doors are
opened. This initiates that the drive is shut down according to
stop Category 1 in compliance with EN 60204-1.
■ A 0 signal is entered at contact 65 (controller enable) of the
drive by resetting the PLC output DO3. The drive is immediately
braked down to 0 speed and the pulses are cancelled.
■ If the drive is stationary (speed = 0), then PLC output DO2
to the internal safety relay of the drive is reset. The internal
safety relay of the drive drops-out and its checkback signal
contacts AS1/2 close (1st shutdown path!).
■ The protective door interlocking is opened by setting PLC
output DO4 to energize coil Y1. When the protective doors
are opened the safety monitoring A2 of the safety circuit is
interrupted.
Powering-up the drive
The drive can be started when the protective doors are closed
and Emergency Stop button S3 is released.
■ When button S1 ("On") is pressed, safety combination A1 is
brought into the operational state. The coil of latch (tumbler)
Y1 is no longer energized by resetting PLC output DO4
- the protective doors are interlocked. Safety combination
A2 is again in an operational state. Line contactor K1 is
energized.
■ Before the selected delay time of safety combination A1
expires, the internal safety relay of the drive must have
already dropped-out and its checkback signal contacts AS
1/2 indicate that the drive is in a safe condition.
■ The safely delayed enable contacts of safety combination A1
open after the selected delay time has expired. This means
that the internal line contactor of the rectifier unit is no
longer energized and the drive is electrically isolated from
the line supply (2nd shutdown path!).
■ The checkback signal of the internal line contactor of the rectifier
unit is monitored in the on circuit of safety combination
A1. If the contactor does not drop-out due to an incorrect
function, then the drive is prevented from restarting after an
Emergency Stop.
■ For a correctly functioning circuit, the internal safety relay
of the drive has already fallen out by this time and its checkback
signals contacts AS1/2 closed. The internal line contactor
of the rectifier unit does not drop-out. If the internal
safety relay does not function correctly, its checkback signal
contacts AS1/2 are not closed, the internal line contactor of
the rectifier unit drops-out and isolates the drive from the
line supply (2nd shutdown path!).
Note
If the protective door interlocking opens before the drive
has braked down to 0 speed as a result of an erroneous
PLC function, then a 0 signal is entered at contact 65
(controller enable) of the drive via the switch S6. The
drive is immediately braked down to speed = 0 and the
pulses cancelled. Opening of the protective doors initiates
the function "safe standstill". It must be ensured
that potentially hazardous motion must have come to a
standstill before a person can reach the potentially hazardous
area!
■ The internal safety relay is energized (PLC output DO2), a 1
signal is entered (PLC output DO3) at contact 65 (controller
enable) of the drive. The drive restarts.
Functional Example No. MC-FE-I-002-V11-EN 421
Ex. No.
2.5