User Manual

SAFETY
Safety handbook page - 35 -
PNSPO
Finger protection system with two
F3SN-A_P14 connected in series.
Protection function:
finger- and hand protection: Operator is close to the danger zone
body protection: 1. access protection: presence of operator in
danger zone visible all the time
2. presence detection: operator has to be
detected all the time
A finger or hand protection system is generally
composed of a type 4, more frequently, or a type
2 safety light curtain (basing on the risk
assessment result), and fixed guards. That allow
to forcing the access to the dangerous zone
through the detection zone of the barrier.
The typical values of resolution are 14mm for
finger protection (this value allow to eliminate the
static factor on the safety distance formula), and
25 to 40mm for hand protection.
The installation of the barrier is also influenced
by the dimension of the emitter/receiver
components and the flexibility of connection: a
protective height equal or similar to the sensor
height and the possibility of a series connection
could be fundamental.
7.2.1 Type 4
The norm EN 61496-2 requires a self-testing function for type 4 AOPDs.
• In case of a faulty condition the systems remains to be safe.
• If the first fault is not detected the second and third fault must not cause a loss of
safety.
• The internal test cycle must be less than the response time of the system.
• The safety level of Type 4 is equal to category 4 (EN954-1).
Further on the EAA effective aperture angle is specified to ± 2.5° from the beam-centre
line.
Faulty condition
Normal
T
T
T
T
T
T
T
T
T
T
T
T
T
Internal
Testc
y
cle
OSSD
Outputs
ON
OF
ON
OFF
Protection
field
free
broken