Safety Integrated - Industry - Siemens

■ This circuit principle is suitable for selectively shutting down
several drives. Protective door 1 acts on drive A, protective
door 2 on drives A and B, protective door 3 on drive B. When
the internal safety relay of the drives functions correctly, the
internal line contactor of the rectifier unit does not drop-out
(also refer to the block diagram above). The following table
Behavior when Emergency Stop is issued
Emergency Stop is initiated using button S9 ("Emergency
Stop"). This initiates that the drives are shut down according
to stop Category 1 in compliance with EN 60204-1.
■ A 0 signal is entered at contacts 65 (controller enable) of
the drive via the enable contact of safety combination A4.
The drives are immediately braked down to 0 speed and the
pulses cancelled. At the same time, the drop-out delay of
time relay K2a/b and the delay time of the safety combination
A4 are started. The drives must have come to a standstill
before these delay times have expired.
Behavior when the protective doors are opened
When protective doors 1-3 are opened, it is initiated that the
associated drives are shut down according to stop Category 1
in compliance with EN 60204-1. It must be ensured that potentially
hazardous motion must have come to a standstill before
a person can reach the potentially hazardous area!
■ A 0 signal is entered at contact 65 (controller enable) of the
drive/drives via the enable contact of the safety combinations
A1, A2 or A3. The drives are immediately braked
down to 0 speed and the pulses cancelled. At the same
time, the switch-out delay of time relays K2a and/or K2b
are started. The drive/drives must have come to a standstill
before these delay times have expired.
■ The internal safety relay of the drive is no longer energized
after the drop-out delay time of time relay K2a or K2b has
expired (1st shutdown path!).
shows how the two drives A and B are dependent on the state
of the protective doors.
Drive A Drive B
Ex. No.
Protective door 1 open Safe standstill Ready
Protective door 2 open Safe standstill Safe standstill 2.7
Protective door 3 open Ready Safe standstill
■ After the drop-out delay time of time relay K2a/b has
expired, the internal safety relays of the drives are no
longer energized (1st shutdown path!).
■ After opening the safely delayed enable contact of safety
combination A4, the internal line contactor of the rectifier
unit is no longer energized and the drives are 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
A4. If the contactor does not drop-out due to an
incorrect function, then the drive is prevented from restarting
after an Emergency Stop.
■ Before the selected delay times of safety combinations A1-
3 expire, the internal safety relays of the drives must have
already dropped-out. Their checkback signal contacts
AS1/2 indicate that the drives are in a safe condition.
■ After the selected delay time has expired, the safely
delayed enable contacts of the safety combinations open.
■ If the internal safety relay of the drives is functioning correctly,
their checkback signal contacts AS1/2 are closed and
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
(2nd shutdown path!).
Functional Example No. MC-FE-I-002-V11-EN 425