Safety Light Curtain
43
Step 1: Calculate the safety clearance S
RT
for reaching through
S
RT
= 2,000 mm/s × ( t
1
+ t
2
+ t
3
) + C
RT
S
RT
= 2,000 mm/s × (0.0162 s + 0.015 s + 0.3 s) + 8 ×(30 mm – 14 mm)
S
RT
= 790 mm
Because SRT > 500 mm
re-calculation with K = 1,600 mm/s
S
RT
= 1,600 mm/s × ( 0.0162 s + 0.015 s + 0.3 s) + 8 ×(30 mm – 14 mm)
S
RT
= 657.92 mm
Step 2: Determine the additional clearance C
RO
• Find height a in table:
here: a = 1,600 mm
• Find height b in table:
here: b = 1,600 mm
• Take the value for C
RO
from the intersection point of the two axes:
here: C
RO
= 750 mm
Step 3: Calculate the safety clearance S
RO
for reaching over
S
RO
= 2.000 mm/s × ( t
1
+ t
2
+ t
3
) + C
RO
S
RO
= 2,000 mm/s × ( 0.0162 s + 0.015 s + 0.3 s) + 750 mm
S
RO
= 1,412.4 mm
Because S
RO
> 500 mm
re-calculation with K = 1,600 mm/s
S
RO
= 1,600 mm/s × ( 0.0162 s + 0.015 s + 0.3 s) + 750 mm
S
RO
= 1,279.92 mm
Step 4: Compare the safety clearance S
RO
and S
RT
S
RT
= 657.92 mm
S
RO
= 1,279.92 mm
S
RO
> SRT , i.e. the safety clearance to be used is 1,279.92 mm.
If the safety clearance of 1,279.92 mm is too large, the SFH can be increased from 1,500 mm to 1,650 mm
(SEFG421), thus reducing the supplement to C
RO
= 450 mm.
This adjustment results in the following:
S
RO
= 2.000 mm/s × ( t
1
+ t
2
+ t
3
) + C
RO
S
RO
= 2,000 mm/s × (0.0172 s + 0.015 s + 0.3 s) + 450 mm
S
RO
= 1,114.4 mm
Because S
RO
> 500 mm
re-calculation with K = 1600 mm/s
S
RO
= 1,600 mm/s × 0.0172 s + 0.015 s + 0.3 s) + 450 mm
S
RO
= 981.52 mm
