REER S.p.A. - Via Carcano, 32 - 10153 Torino, Italy - Internet: www.reersafety.com - e-mail: [email protected]
24
8541205 - rev
.1 - 02/09/2019
INSTALLATION
CALCULATION OF THE SAFETY DISTANCE
The effectiveness of the protection heavily depends
on the correct positioning of the curtain according
to the danger. The curtain must be positioned at a
distance greater than or equal to the minimum safety
distance S so that reaching the dangerous point can
only be achieved after the dangerous operation of the
machine has stopped.
The positioning shall be such that:
• Reaching the dangerous point is avoided without
crossing the area controlled by the curtain.
• No person is allowed in the dangerous area
without this being detected. For this case,
additional safety devices (e.g. horizontal light
curtains) may be required.
The ISO 13855 standard provides the elements for
calculating the safety distance.
If the machine under consideration is subject to a type
C specific standard, reference should be made to this
rule.
If the S distance calculated appears to be excessive,
it is necessary:
•
to reduce the total time the machine is off
• to improve the resolution of the curtain.
GENERAL FORMULA FOR CALCULATING THE SAFETY DISTANCE
S = K x T + C
S
minimum safety distance between the protection and the dangerous point, expressed in mm.
K
advance speed of the body or parts of the body, expressed in mm per second.
K values can be:
K = 2000 mm per second for safety distances up to 500 mm
K = 1600 mm per second for safety distances over 500 mm
T
Total machine stopping time including:
T1 response time of the protection device in seconds
T2 machine reaction time to stop the hazardous operation, in seconds.
C
additional distance expressed in mm.
1
2
3
S
C
KxT
a
1. Dangerous point
2. Protected plane
3. Reference plane
a. Height of dangerous point
S. Safety distance
Mechanical installation
