13
www.abb.com/lowvoltage
2TLC172015M0201, rev. D
c)
Compare S
RT
and S
RO
. The minimum distance S is the greater of the two.
The following table is valid only for vertically assembled light grid with 2, 3, or 4 beams
(shall never be assembled horizontally):
Horizontally assembled light curtain
The minimum distance S from hazardous machinery to the farthermost beam is calculated using the same
formula as above but with different parameters, as follows:
S = (K × T) + C
K
= 1600 mm/s. Approach speed of body parts towards hazardous area.
T
= Overall system stopping performance = T1 + T2, where:
T1 = reaction time of light curtain (s)
T2 = stopping time of machine, including reaction time of control system (s)
C
= 1200 - 0.4 × H. Shall not be less than 850 (mm)
H
= 15 × (d-50). Minimum allowed height of detection zone above reference plane (mm)
NB!
Shall not be less than 0 or greater than 1000.
d = resolution (mm) = 14 mm for FII-4-14 and 30 mm for FII-4-30.
S
= minimum distance in mm.
H = the optical field shall not be higher
than 1000 mm.
BEAM HEIGHT ABOVE FLOOR
4 beams (900 unit)
4 beams (1200 unit)
3 beams
2 beams
1st beam
300 mm
300 mm
300 mm
400
a
mm
2nd beam
600 mm
700 mm
700 mm
900 mm
3rd beam
900 mm
1100 mm
1100 mm
4th beam
1200 mm
1500 mm
a
For the lowest beam 400 mm can only be used when the risk assessment allows it.
