F3SJ-E/F3SJ-B/F3SJ-A
42
Detection Zone Parallel to Direction of Approach
Use K = 1,600 mm/s and C = (1200 - 0.4 x H) in formula (1) for
calculation. Note that C must not be less than 850 mm.
S = 1,600 mm/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 - 50 mm)
≥
0 mm
Also, you must include a hazardous condition under which a
person may go through under a detection zone if H exceeds 300
mm (200 mm for other purpose than industrial use) into risk
assessment.
[Calculation example]
When Tm = 0.05 s, Ts = 0.01 s, and d = 14 mm:
S = 1,600 mm/s x (0.05 s + 0.01 s) + 1200 - 0.4 x 500 mm
= 1096 mm
When a warning zone is configured as in the figure, you must
calculate L, a distance from an end of casing to a detection zone,
using a formula below:
L = (Total number of F3SJ beams - number of warning zone beams
- 1) x P + 10
• P: Beam Gap (mm)
• F3SJ-A
@@@@
P14/N14 . . . 9 mm
• F3SJ-A
@@@@
P20/N20 . . . 15 mm
• F3SJ-A
@@@@
P25/N25 . . . 20 mm
• F3SJ-A
@@@@
P30/N30 . . . 25 mm
• F3SJ-A
@@@@
P55/N55 . . . 50 mm
Refer to the F3SJ User's Manual for details. For manual number,
check the "
Related Manuals
" at the end of the catalog.
How to calculate the safety distance specified by
American standard ANSI B11.19
(Ref.)
If a person approaches the detection zone of the F3SJ
orthogonally, calculate the safety distance as shown below.
S = K x (Ts + Tc + Tr + Tbm) + Dpf
• S: Safety distance
• K: Approach speed to the detection zone
(the value recommended by OSHA standard is 1,600 mm/s)
Approach speed K is not specified in the ANSI B.11.19 standard.
To determine the value of K to apply, consider all factors, including
the operator's physical ability.
• Ts = Machine's stop time (s)
• Ts = Response time of the F3SJ from ON to OFF (s)
• Tc = Machine control circuit's maximum response time required
to activate its brake (s)
• Tbm = Additional time (s)
If a machine has a brake monitor, "Tbm = Brake monitor setting
time - (Ts + Tc)". If it has no brake monitor, we recommend using
20% or more of (Ts + Tc) as additional time.
• Dpf = Additional distance
According to ANSI's formula, Dpf is calculated as shown below:
Dpf = 3.4 x (d - 7.0): Where d is the detection capability of the F3SJ
(unit: mm)
[Calculation example]
When K = 1,600 mm/s, Ts + Tc = 0.06 s, brake monitor setting time
= 0.1 s, Tr = 0.01 s, and d = 14 mm:
Tbm = 0.1 - 0.06 = 0.04 s
Dpf = 3.4 x (14 - 7.0) = 23.8 mm
S = 1,600 mm/s x (0.06 s + 0.01 s + 0.04 s) + 23.8 mm = 199.8 mm
H
Safety distance (S)
Hazard
H
Safety
distance (S)
Hazard
Distance L from casing end
to detection zone
Detection
zone
W
arning
zone