5
CSS 34F0
CSS 34F1
Operating instructions
Safety sensor
EN
Maximum misalignment from side
Y
X
Actuation from side
The long side allows for a maximum height misalignment (x) of sensor
and actuator of 36 mm (e.g. mounting tolerance or due to guard door
sagging). Increased misalignment, max. 53 mm, possible when the
CST 34-S-2 actuator is used. The axial misalignment (y) is max.
± 10 mm.
Maximum misalignment from front
Z
Actuation from front
The front face allows for an axial misalignment
(Z) of max. ± 8 mm.
3.5 Adjustment
The distance between the sensor and the actuator must be set to < s
ao
.
If variations in the clearance between the sensor and the actuator must
be detected (e.g. sagging of a safety guard), this distance must be
reduced by 4 mm. The yellow LEDs and the diagnostic output indicate
the different ranges.
Recommended Adjustment
Align the safety sensor and actuator at a distance of 0.5 x s
ao
.
The correct functionality of both safety channels must be checked by
means of the connected safety-monitoring module.
4. Electrical connection
4.1 General information for electrical connection
The electrical connection may only be carried out by
authorised personnel in a de-energised condition.
The power supply for the safety sensors must provide protection
against permanent over-voltage. Under fault conditions, the voltage
must not exceed 60 V. The use of PELV supply units is recommended.
The self-monitoring safety sensors of the CSS 34F0 or CSS 34F1
series can replace the safety-monitoring module. Therefore, they can
only be used as first sensor of a series-wired sensor chain (refer to
operating instructions CSS 34F0 / CSS 34F1).
If a safety chain including multiple sensors is set up, only the first
device of this chain may be a CSS 34F. type sensor. All other devices of
the chain must be of the default CSS 34 type. The CSS 34F. performs
the check of the connected contactors or relays and the optional button
for the entire chain.
Requirements for the connected safety-monitoring module
• Dual-channel safety input, suitable for p-type safety sensors with NO
function.
• Digital inputs to EN 61131-2, Table "Standard operating ranges for
digital inputs (current sinking)"
The safety sensors cyclically switch off the output to test them. The
switch-off times of max. 500 μs must be tolerated by the switching
device. An extension with short-circuit recognition for the evaluation is
not required. Note on the total length of a safety sensor chain, refer to
paragraph "Series-wiring". The maximum load current of 250 mA per
safety channel must be observed. Contactors with higher load currents
must be controlled by intermediate control relays.
Information for the selection of suitable safety-monitoring
modules can be found in the Schmersal catalogues or in the
online catalogue on the Internet: www.schmersal.net.
If the safety sensor is connected to electronic safety-
monitoring modules, we recommend that you set a
discrepancy time of 100 ms. The safety inputs of the safety-
monitoring module must be able blanking a test impulse of
approx. 1 ms. The safety-monitoring module does not need to
have a cross-wire short monitoring function, if necessary, the
cross-wire short monitoring function must be disabled.
4.2 Series-wiring
Series-wiring can be set up. The number of devices is limited for
safety reasons. Series-wiring of up to 31 CSS 34F0 or CSS 34F1-…-SD
devices with serial diagnostics is possible. A 200 m long sensor chain
can be set up. Please note that voltage losses could occur (due to
cable length, cable section, voltage drop/sensor)! For longer cable
lengths, the section of the connecting cables must be taken as large as
possible.
Wiring examples for series-wiring, refer to appendix
Protection is not required when pilot wires are laid. The cables however
must be separated from the supply and energy cables. The max. fuse
rate for a sensor chain depends on the section of the connecting cable
of the sensor.
Wiring capacitance for serial diagnostics
The connecting cable of the safety sensor must have a maximum
length of 200 m; its wiring capacitance must not exceed 50 nF.
Depending on the strand structure, normal unshielded 200 m long
control cables LIYY 0.25 mm² to 1.5 mm² have a wiring capacitance of
approx. 20 … 48 nF.
When wiring SD devices, please observe the voltage drop on
the cables and the current carrying capacity of the individual
components.
Accessories for the series-wiring
For convenient wiring and series-wiring of SD components,
the SD junction boxes PFB-SD-4M12-SD (variant for the
field) and PDM-SD-4CC-SD (variant for control cabinet on
carrier rail) are available along with additional comprehensive
accessories. Detailed information is available on the Internet,
www.schmersal.net.