Leuze electronic MLC 520 EX Series User Manual

Mounting
Leuze electronic MLC 530 33
6.1.2 Calculation of safety distance S
RT
or S
RO
if protective fields act orthogonally to the approach direction
With vertical protective fields, EN ISO 13855 differentiates between
•S
RT
: safety distance concerning access through the protective field
•S
RO
: safety distance concerning access over the protective field
The two values are distinguished by the way additional distance C is determined:
•C
RT
: from a calculation formula or as a constant see chapter 6.1.1 „Calculation of safety distance S“
•C
RO
: from a table (see table 6.1)
The larger of the two values S
RT
and S
RO
is to be used.
Calculation of safety distance S
RT
acc. to EN ISO 13855 when access occurs through the protective field:
Calculation of safety distance S
RT
for point of operation guarding
S
RT
[mm] = Safety distance
K [mm/s] = Approach speed for point of operation guarding with approach reaction and normal ap-
proach direction to the protective field (resolution 14 to 40 mm): 2000 mm/s or
1600 mm/s, when S
RT
> 500 mm
T [s] = Total time of the delay, sum from (t
a
+ t
i
+ t
m
)
t
a
[s] = Response time of the protective device
t
i
[s] = Response time of the Safety Relay
t
m
[s] = Stopping time of the machine
C
RT
[mm] = Additional distance for point of operation guarding with approach reaction with resolu-
tions of 14 to 40 mm, d = resolution of protective device C
RT
= 8  (d - 14) mm
Calculation example
The feeding-in area in a press with a stopping time (including press Safety PLC) of 190 ms is to be safe-
guarded with a Safety Light Curtain with 20 mm of resolution and 1200 mm of protective field height. The
Safety Light Curtain has a response time of 22 ms.
 Calculate safety distance S
RT
using the formula acc. to EN ISO 13855.
K [mm/s] = 2000
T [s] = (0.022 + 0.190)
C
RT
[mm] = 8  (20 - 14)
S
RT
[mm] = 2000 mm/s  0.212 s + 48 mm
S
RT
[mm]= 472
S
RT
is smaller than 500 mm; this is why the calculation may not be repeated with 1600 mm/s.
Calculation of safety distance S
RT
for access guarding
S
RT
[mm] = Safety distance
K [mm/s] = Approach speed for access guarding with approach direction orthogonal to the protec-
tive field: 2000 mm/s or 1600 mm/s, if S
RT
> 500 mm
T [s] = Total time of the delay, sum from (t
a
+ t
i
+ t
m
)
t
a
[s] = Response time of the protective device
t
i
[s] = Response time of the Safety Relay
t
m
[s] = Stopping time of the machine
C
RT
[mm] = Additional distance for access guarding with approach reaction with resolutions of
14 to 40 mm, d = resolution of protective device C
RT
= 8  (d - 14) mm. Additional dis-
Implement the necessary stepping behind protection, for example with OSSD linkage, see
chapter 4.6.2 „Linking of electronic safety-related switching outputs“.

Leuze electronic MLC 520 EX Series Specifications

General

Brand	Leuze electronic
Model	MLC 520 EX Series
Category	Lighting Equipment
Language	English