Implementation Of Example 1 - Emerson AVENTICS AV Notice D'instruction

• Disconnection of fluid power supply: PL
and of electrical energy supply: PL

3.4.1 Implementation of example 1

According to ISO 13849, PL = e can be achieved with category 3 if the following
circumstances apply:
• DC = average
avg
• MTTF = high
Category for example, PL = e
r
Category B
I L O
Performance Level a
≥ 10 bis < 10 [h ]
-5 -4 -1
Performance Level b
≥ 3 * 10 bis < 10 [h ]
-6 -5 -1
Performance Level c
≥ 10 -6 bis < 3 * 10 -6 [h -1 ]
Performance Level d
≥ 10 -7 bis < 10 -6 [h -1 ]
Performance Level e
≥ 9 * 10 bis < 10 [h ]
-10 -7 -1
DC None
MTTF MTTF
n ≥ 3 to < 10 years m ≥ 10 to < 30 years
D D
low medium
Fig. 3: Implementation of example 1: PL
high
According to the simplified approach of ISO 13849-1, the 4 classes for the diag-
nostic coverage DC are defined as follows:
• none: DC < 60 %
• low: 60 % < DC < 90 %
• average: 90 % < DC < 99 %
• high: 99 % < DC
Design and technical implementation of safety function
Manual workplace
TM=20 years
d/a=320 days
h/d=24 h / min. 10 sec cycle time = 55,296,000 switching cycles for working and
main air valve
During setup operation, movable, separating guards must be bridged and open,
and fixed separating guards must be mounted.
AVENTICS™ AV | R412018148-BAL-001-AB | English
≥ d => 2-channel
r
≥ d => 2-channel recommended
r
Category 1 Category 2 Category 3
I L O I L O I1 L1 O1
O
TE I2 L2 O2
TE
None Low | medium Low | medium
MTTF
h ≥ 30 to < 100 years (resp. < 2.500 years in Cat. 4)
D
high
with category 3, DC = average, MTTF
e
INFO: A single error does not lead to loss of the safety function. Some, but not all,
faults are detected. However, an accumulation of undetected faults can lead to a
loss of the safety function.
Valve selection
Category 4
I1 L1 O1
I2 L2 O2
Fig. 4: Wiring diagram: valve selection
• Defined, safe switching position in state without current by mechanical spring
• Pressure lines are blocked in the state without current
• Exhaust lines are not open
High
• Cylinder after EMERGENCY STOP cannot be moved, i.e. personal rescue is re-
quired
• Braking of decelerated masses possible
=
D
• Safe stopping during vertical movements with masses (from PL
ditional measures -> 2-channel)
• JOG operation is possible (cylinder stroke jogging)
• Transverse influence by exhaust air from large neighboring cylinders not pos-
sible
• Suitable up to Performance Level PL
• Extend and retract the permissible hazardous direction of movement of the
cylinder
• Service life of the valves has been tested according to ISO 19973-1 and -2
Pneumatic safety switch category 3 PL
Designation:
Prevention of unexpected start-up (PUS) acc. to VDMA standard sheet 24584.
Blocking the volume flows into and out of both piston chambers.
INFO: Observe during restart:
Cylinder chambers can exhaust due to leakage of individual components.
INFO: Test pulses can cause the valves to switch.
4 4 4
1 1
2 2
4 2
14 12
X 5 1 3
(additional measures see g Fig. 5.)
e
e
only with ad-
d
16