F3SJ-E/F3SJ-B/F3SJ-A
40
Safety Safety Distance
The safety distance is the distance that must be set between the F3SJ
and a machine's hazardous part to stop the hazardous part before a
person or object reaches it. The safety distance varies according to
the standards of each country and the individual specifications of
each machine. In addition, the calculation of the safety distance
differs if the direction of approach is not vertical to the detection zone
of the F3SJ. Always refer to relevant standards.
Make sure to secure the safety distance (S) between the F3SJ
and the hazardous part. Failure to do so may prevent the
machinery from stopping before a person reaches the
hazardous part of the machinery, and result in serious injury.
Note:
The response time of a machine is the time period from when
the machine receives a stop signal to when the machine's
hazardous part stops. Measure the response time on the actual
system. Also, periodically check that the response time of the
machine has not changed.
How to calculate the safety distance specified by
International Standard ISO 13855 (European Standard EN
ISO 13855) (Reference)
Detection Zone Orthogonal to Direction of Approach
S = K x T + C . . . Formula (1)
• S: Safety distance
• K: Approach speed to the detection zone
• T: Total response time of the machine and F3SJ
• C: Additional distance calculated by the detection capability of
the F3SJ
<System with a detection capability of 40 mm max.>
Use K = 2,000 mm/s and C = 8 x (d - 14 mm) in equation (1) for the
calculation.
S = 2,000 mm/s x (Tm + Ts) + 8 x (d - 14 mm)
• S = Safety distance (mm)
• Tm = Machine's response time (s)
• Ts = Response time of the F3SJ from ON to OFF (s)
• d = Size of F3SJ's detection capability (mm)
[Calculation example]
When Tm = 0.05 s, Ts = 0.01 s, and d = 14 mm:
S = 2,000 mm/s x (0.05 s + 0.01 s) + 8 x (14 mm - 14 mm)
= 120 mm . . . Formula (2)
If the result is less than 100 mm, use S = 100 mm.
If the result exceeds 500 mm, use the following formula where
K = 1,600 mm/s.
S = 1,600 mm/s x (Tm + Ts) + 8 x (d - 14 mm) . . . Formula (3)
If the result of this Formula (3) is less than 500 mm,
S = 500 mm
<System with a detection capability larger than 40 mm>
Use K = 1,600 mm/s and C = 8 x (d - 850 mm) in equation (1) for
the calculation.
S = 1,600 mm/s x (Tm + Ts) + 850 x (d - 14 mm) ... Formula (4)
• S = Safety distance (mm)
• Tm = Machine's response time (s)
• Ts = Response time of the F3SJ from ON to OFF (s)
[Calculation example]
When Tm = 0.05 s, Ts = 0.01 s:
S = 1,600 mm/s x (0.05 s + 0.01 s) + 850 mm
= 946 mm
WARNING
F3SJ-E F3SJ-B F3SJ-A
Hazard
Safety distance (S)