SF2 Series
Instruction Manual
10
2.2.1. Minimum installation distance
The safety device must be placed at a specific safety distance (Fig.5).
This distance must ensure that the dangerous zone cannot be reached
before the dangerous motion of the machine has been stopped by the
ESPE.
The safety distance depends on 4 factors, according to the EN-999,
775 and 294 Standards:
1
Response time of the ESPE (the time between the effective beam
interruption and the opening of the OSSD contacts).
2
Machine stopping time (the time between the effective opening of
the contacts of the ESPE and the real stop of the dangerous
movement of the machine).
3
ESPE resolution
4
Approaching speed of the object to be detected.
Fig. 6
The following formula is used for the calculation of the safety distance:
S = K (t
1
+ t
2
) + C
where
:
S
= Minimum safety distance in mm.
K
= Speed of the object, limb or body approaching the dangerous
area in mm/s
t
1
= Response time of the ESPE
in seconds (
see section 9
“Technical
data”
)
t
2
= Machine stopping time in seconds.
d
= Resolution of the system.
C
=
8 (d -14)
for device with resolution
≤
40mm
=
850 mm
for device with resolution
>
40 mm
