Calculation formula for the minimum safety distance for AOPD with perpendicular approach with respect to reaching through (point of operation guarding):
The following calculation formulas apply for applications of optoelectronic protective devices with approach direction of body parts in an angle of 30° to 90° to the protective field level:
S for protective devices with detection value d (resolution) ≤ 40 mm:
S = (2000 x T) + 8 x (d – 14)
S must always be at least 100 mm. If the calculation results in S > 500 mm, the calculation may be made again with
K = 1600 mm/s. In this case S must be at least 500 mm.
If electro-sensitive protective equipment is also used to control the machine (safety light curtains with single or double cycle function), its resolution must be ≤ 30 mm. A minimum distance S of 150 mm may not be exceeded regardless of the calculation. With d = 14 mm this minimum distance is 100 mm.
Machine-specific regulations such as EN 692 or EN 693 may prescribe values for S that differ from the formula.
S for protective devices with 40 < d < 70 mm:
These kinds of protective devices may only be used if the risk assessment determines that the insertion of the hands does not have to be detected. The additional 850 mm to be added on corresponds with the arm length:
S = (1600 x T) + 850 mm
Height of the top beam of the protective device ≥ 900 mm
Height of the bottom beam of the protective device ≤ 300 mm
|a =||Safety distance S and DS|
|b =||Measures to prevent penetration from above|
|c =||Measures to prevent penetration from the sides|
|d =||Measures to prevent penetration from the rear|
|e =||Measures to prevent penetration from below|
|f =||75 mm maximum distance to prevent stepping behind. |
If this value cannot be achieved because of the safety distance, other measures, e.g. mechanical barriers, must guarantee the required maximum distance of 75 mm.
|g =||Height of the bottom beam above the reference plane|
|h =||Height of the top beam above the reference plane|
Fig. 4.2.1-4: Approach of the body part from a right-angle to the protective field level