How To Calculate Safety Distance - Honeywell FF-SB12 Series Installation Manual

How to Calculate Safety Distance

IMPROPER SAFETY DISTANCE
• Calculate safety distance using formula D
− D is the safety distance OSHA 29 CFR 1910.217 (c) (3) (iii) (e)
S
− V is the hand speed constant of 63 inches per second
− t is the response time of the FF-SB light curtain
1
− t is the stopping time of the machine including interconnecting components such as relays, solenoids, and
2
brakes, and C is additional safety distance.
• Obtain C, the additional safety distance from local safety agency.
Failure to comply with these instructions could result in death or serious injury.
The safety distance is the minimum distance between the sensing field and the danger zone. This distance
ensures that the danger zone cannot be reached until the machine motion has been stopped.
Calculate the safety distance (see figure 2-1) using the following formula:
− D is the safety distance from the light curtain sensing field to the danger zone.
S
− V is the velocity of movement into the danger zone; the OSHA hand speed constant is 63 inches per
second; see local health and safety regulations for current value.
− t is the response time of the FF-SB light curtain.
1
− t is the stopping time of the equipment guarded by the light curtain including interconnecting components
2
such as all mechanical, electromechanical, and electronic parts such as relays, solenoids, and brakes.
− C is additional safety distance. See local health and safety regulations for this value.
Figure 2-1 Light Curtain Safety Distance Diagram
32
>V(t +t )+C where,
S 1 2
D >V(t +t )+C where,
S 1 2
D
S
107062-12 EN FR26 GLO 501 Printed in France