... what are the security requirements for ESPD systems to secure the loading and unloading of products?

 

When it comes to the safety of packaging machines, experienced designers appreciate the Type C series of standards DIN EN 415. The ten parts of this standard describe a large number of requirements for machines. Currently these are:
The various machines are usually closed systems that operate fully automatically. In order to transport products and materials into and out of the safety area, non-contact protective devices are used, especially for larger openings, which are controlled by corresponding safety functions. It must be ensured that products and materials can be transported in and out without persons being able to enter the danger zone undetected through these openings. One way to protect such openings is to bypass or hide the ESPD system. This function is also called muting.
DIN EN 415-10:2014, Section 5.2.1.4 places corresponding requirements on the function of such systems, as the following abbreviated copy shows.
a) The bypass period shall be limited to a period which is only long enough to allow the product to pass through the detection zone.
b) The configuration of the bypass sensors shall be capable of distinguishing a person from the material;
c) All bypass functions must have the same performance level;
d) There must be no operational waiting position for a product within the bypass area.

 

DIN EN 415-1:2014

Terminology and classification of packaging machines and related equipment 

DIN EN 415-3:1999+A1:2009

Forming, filling and closing machine

DIN EN 415-5:2006

Wrapping machines

DIN EN 415-6:2013

Pallet wrapping machines

DIN EN 415-7:2006+A1:2008

Group packing machines

DIN EN 415-8:2008

Strapping machines

DIN EN 415-9:2009

Noise measurement methods for packaging machines, packaging lines and auxiliary equipment - Accuracy classes 2 and 3

DIN EN 415-10:2014

General requirements

 

For further details, DIN EN 415-10:2014 refers to DIN EN IEC 62046:2019.
Section 5.5.3 requires the bypass function to be automatically initiated and terminated. This can be done by using appropriately selected and arranged sensors or, in some cases, signals from the safety-related control system. No bypass condition shall be made possible by faulty signals, sequences or timing of the bypass sensors or signals.
The control circuit performing the bypass function must have a suitable safety-related performance level (SIL or PL, see DIN EN 62061:2016 or DIN EN 13849-1:2016).
In addition, the safety of the machine during muting must be ensured by other means, for example by maintaining the following lateral distances and by ensuring that the load is at least 900 mm high.
If the requirements described above do not guarantee safety, other solutions may be used, such as interlocking function.

 


 

Systems with two beams 
L-configuration with time control of the sensors (only run out of the danger zone)

diagram with two beams

 


 

Systems with two beams
T-configuration with time control of the sensorsfor
inward and outward transfer from the danger area.

diagram system with two beams- crossed beams - variant 1 diagram system with two beams- crossed beams - variant 1

 


 

Systems with four beams 
T configuration with sequential process
for inward and outward transfer from the danger area.

diagram system with four beams- variant 1

diagram system with four beams - variant 1