Omron F3SJ-A P 01TS Series User Manual page 67

• Ts: Response time of the F3SJ from ON to OFF (s)
• a: Height of machine hazardous zone (mm)
• b: Height of upper edge of detection zone (mm)
When Tm = 0.05 s, Ts = 0.01 s, a = 1,400 mm, b = 1,500 m:
From the table above, Cro = 850 mm. Since b is between 1,400 mm and 1,600 mm, b = 1,400 mm
which has the greater Cro value, shall be used.
S = 2,000 mm/s × (0.05 s + 0.01 s) + 850 mm
= 970 mm
Since 970 mm is greater than 500 mm, use K = 1,600 mm/s and recalculate it.
S = 1,600 m/s × (0.05 s + 0.01 s) + 850 mm
= 946 mm
Compare S = 946 mm with the calculation in "If a person approaches the detection zone of the F3SJ
perpendicularly", and choose the larger value as the safety distance.
For the system with a detection capability of 40 mm max., the safety distance S is 946 mm since this
is larger than S = 120 mm calculated in the calculation example of "If a person approaches the
detection zone of the F3SJ perpendicularly".
For the system with a detection capability larger than 40 mm, the safety distance S is 946 mm since
this is the same value as S = 946 mm calculated in the calculation example of "If a person
approaches the detection zone of the F3SJ perpendicularly".
In case of horizontal approach of a human body to F3SJ's detection zone
Use K = 1,600mm/s and C = (1200 - 0.4 x H) in
formula (1) for calculation.Note that C must not be
less than 850mm.
S = 1,600mm/s x (Tm + Ts) + 1200 - 0.4 x H
•S = Safety distance (mm)
•Tm = Machine's response time (s)
•Ts = Response time of F3SJ from ON to OFF (s)
•H = Installation height (mm)
Note that H must satisfy:
1000 >= H >= 15 (d - 50mm) >= 0mm
Also, you must include a hazardous condition under which a person may go through under a detection
zone carelessly if it exceeds 300mm (200mm for other purpose than industrial use) into risk
assessment.
[Calculation example]
When Tm = 0.05s, Ts = 0.01s, and d = 20mm:
S = 1,600mm/s x (0.05s + 0.01s) + 1200 - 0.4 x 500mm
= 1096mm
 How to calculate the safety distance specified by American standard ANSI B11.19
(reference)
If a person approaches the detection zone of the F3SJ perpendicularly, calculate the safety distance as
shown below.
Wiring/Installation
Safety distance (S)
Hazard
E
F3SJ-A
49
User's Manual