ESPE Applications
5.1-
Pilz GmbH & Co. KG, Felix-Wankel-Straße 2, 73760 Ostfildern, Germany, Telephone: +49 711 3409-0, Telefax: +49 711 3409-133, E-Mail: [email protected]
2009-01
2.3-2
2.3
PL e of EN ISO 13849-1, SIL 3 of EN 62061
PNOZ s4 - PSEN op4H light curtain
Features
Dual-channel operation with detection
of shorts across contacts via light
curtain
Monitored reset with falling edge
Light curtain with semiconductor
output
Contact expansion through positive-
guided contactors
Feedback loop to monitor contact ex-
pansion
Description
Light curtain function
The interruption of light curtain PSEN op4H
(B1/B2) is signalled to the safety relay PNOZ
s4 (K2) via the two semiconductor outputs
on receiver B2.
The semiconductor outputs on the safety
light curtain’s receiver B2 are opened as
soon as the light curtain is interrupted. As a
result the input circuit on the safety relay
PNOZ s4 (K2) is interrupted and the safety
contacts open. Contactors K3 and K4 de-
energise.
The top and bottom DIP switches on the
receiver B2 must be set at the same
position. For the light curtain to reset
automatically, number 4 on both DIP
switches must be switched to ON.
Settings on the unit
The terminator on the PNOZ s4 must be
connected.
The operating mode selector switch
(mode) on the safety relay PNOZ s4 must
be set to “Monitored reset, falling edge
without detection of shorts across
contacts (In2+)“.
Start/reset
The safety relay PNOZ s4 (K2) can be
started by pressing reset button S3 if:
The light curtain is not interrupted and
The semiconductor outputs on safety
light curtain B1/B2 are closed and
Contactors K3 and K4 have de-
energised.
Feedback loop
The positive-guided N/C contacts on
contactors K3 and K4 are monitored in
feedback loop S12-S34 of the safety relay.
Safety assessment
The safety relay PNOZ s4 (K2) and
contactors K3, K4 must be installed in a
single mounting area (control cabinet) in
order to exclude a short across the
output.
Earth faults and shorts between contacts
in the input circuit are detected via the
light curtain.
A fault on the device does not lead to the
loss of the safety function.
A single fault in the light curtain is
detected.
The safety relay PNOZ s4 (K2) can be
started when the input circuit at K2 is
closed first, followed by reset button S3.
This avoids an unwanted reset before the
input circuit is closed or as a result of the
reset button being overridden.
If the position of the operating mode
selector switch (mode) is changed during
operation, an error message will be
triggered; the safety contacts on K2
open. This fault condition can only be
rectified by switching the supply voltage
on the safety relay K2 off and then on
again.
Pilz products
Number
Designation
Order number
1
PNOZ s4
750 104
1
PSEN op4H-30-150
630 159
