Safety Functions Of Arex™ 400
User Manual 89
Example 1
Risk Analysis of a fully automatic laser processing machine that operates only
when protection system is disengaged.
• Operative cycle: 500 pcs/hour, 3 shifts (8h/shift) 35
0 days/year
• Dedicated enclosures prevent laser emission also during parts loading/
un
loading
• An interlocked door is
dedicated to maintenance and cleaning
• Maintenance technicians are SK
ILLED on laser risks and have specific DPI
• In case of access line is s
topped and restarted
LASER RISK ASSESSMENT: H
AZARD, direct and scattered laser radiation:
• RISK SEVERITY: SEVERE (irreversible eye damage)
•RISK FREQUENCY: RARE (1/month for maintenance)
• AVOIDANCE PROBABILITY: POSSIBLE (with DPI)
RISK REDUCTION: INTERLOCKED DOOR
Estimation of PLr for door interlock safety function
• SEVERITY: SEVERE S2
• FREQUENCY: SELDOM F1
• POSSIBILITY OF AVOIDING HAZARD: POSSIBLE P1
Severity of injury (S)
S1 Slight (normally reversible injury)
S2 Serious (normally irreversible injury or death)
Frequency and/or exposure time to hazard (F)
F1 Seldom to less often and/or exposure time is short
F2 Frequent to continuous and/or exposure time is long
Possibility of avoiding hazard or limiting harm (P)
P1 Possible under specific conditions
P2 Scarcely possible
PLr = PLc
Restart: manual reset
Door Switch
Safety Controller Arex™ 400 SLO - Safety Circuit
Input
Subsystem
Logic
Subsystem
Output
Subsystem
PLr=PLc