6
SICK WSU 26/2 – WEU 26/2
8 008 692/9-12-99 T chnical D scription · WSU/WEU 26-2 © SICK AG · Saf ty Syst ms · G rmany · All rights r s rv d
5 Mechanical Arrangement and Mounting
5 M chanical Arrang m nt
Fig. 4: Saf ty distanc to light b am
Table 1 shows which C valu must
b us d for which application.
Number of beams 010203
H ight of b am(s) 750 400 0300
abov floor (mm) 900 0700
1100
C 1200 850 0850
Tabl 1: H ight of b ams abov floor
pr EN 999
Saf ty of machin ry
Approach sp d of body parts
for arrang m nt of prot ctiv
syst ms
Th WSU/WEU must b attach d such that, if th light b am is
brok n during hazardous mov m nt of th machin ry, th point-
of-op ration can only b r ach d wh n th pow r-driv n
machin ry is no long r in a hazardous stat .
For this purpos , a saf ty distanc must b maintain d b tw n th
light b am and th n ar st boundary of th point-of-op ration.
This saf ty distanc is d t rmin d according to pr EN 999.
P opl within th hazardous ar a but outsid th light b am ar
not d t ct d. It must, how v r, b nsur d that any hazardous
stat can only b initiat d wh n th r is no on in th hazardous
ar a.
Us and mounting of th prot ctiv syst ms is subj ct to th r l -
vant official rul s and r gulations. Th s provisions diff r d p nding
on th ar a of application.
5.1 Safety distance
Th WSU/WEU must b attach d
such that, if th light b am is
brok n during hazardous
mov m nt of th machin ry, th
point-of-op ration can only b
r ach d wh n this hazardous
mov m nt has c as d. For this
purpos , a saf ty distanc S must
b maintain d b tw n th n ar st
boundary of th point-of-op ration
and th light b am (Fig. 4). Th
saf ty distanc d p nds on th
machin stopping tim and on th
approach sp d of th p rsonn l.
Th machin stopping tim must b
d t rmin d by r p ating
m asur m nts und r practical
conditions. 1.6 m/s is th
r comm nd d approach sp d.
Th saf ty distanc is calculat d as
follows:
S = v (t1 + t2) + C
S Saf ty distanc (mm)
v Approach sp d
1.6 m/s
t1Machin stopping tim (ms)
t2R spons tim of WEU (22 ms)
C D p nd nt on numb r of b ams
(1, 2, or 3), s Tabl 1
M chanical
saf guarding
Point-of-op ration
S
Entry/ xit
guarding
with
WSU/WEU Dir ction
of ntry
into
hazardous
ar a
