Mounting
Leuze electronic
MLC 520S
18
NOTICE
If longer stopping times are determined during regular inspections, an appropriate additional
time must be added to t
m
.
6.1.2
Calculation of safety distance if protective fields act orthogonally to the approach direction
With vertical protective fields, 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 the following table “Reaching over the vertical protective field of electro-sensitive protective
equipment (excerpt from ISO 13855)”
The larger of the two values S
RT
and S
RO
is to be used.
Calculation of safety distance S
RT
acc. to 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 approach di-
rection 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 resolutions of
14 to 40 mm, d = resolution of protective device C
RT
= 8 × (d - 14) mm
Calculation of safety distance S
Ro
acc. to ISO 13855 when protective field is accessed from above:
Calculation of safety distance S
Ro
for point of operation guarding
S
RO
[mm]
=
Safety distance
K
[mm/s]
=
Approach speed for point of operation guarding with approach reaction and normal approach di-
rection to the protective field (resolution 14 to 40 mm): 2000 mm/s or 1600 mm/s, when
S
RO
> 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
RO
[mm]
=
Additional distance in which a body part can move towards the protective device before the pro-
tective device triggers: value (see the following table “Reaching over the vertical protective field
of electro-sensitive protective equipment (excerpt from ISO 13855)”).
