rQx
Lifetime Supporting Member
Hi,
I'm reading up on safety in control systems and have a few questions.
This is according to 13849-1.
I have never been involved with designing safety according to a risk analysis so this is just theoreticly questions.
I understand that the risk analysis is providing me with a PL and I must design the safety function according to this. For instance a magnetic switch on a door.
1. How about the emergency stop that is a complementary safety function? Do I get a PL for this or are emergency stops excluded from 13849-1 PL design?
2. I have heard and seen that some say that you have to design for atleast PL c. Where can I read this in a standard?
3. In the machine directive EN-60204-1 10.7.3 it says:
"Where a stop category 0 is suitable, the supply disconnecting device may
serve the function of emergency stop where:
- it is readily accessible to the operator and
- it is of the type descibed in 5.3.2 a),b),c) or d)
Where intended for emergency use, the suppy disconnecting device
shall meet the colour requirements of 10.2.1"
So this means that I can use the supply disconnecting device for emergency stop? How does this compare to the 13849-1? There is plenty of machines (drilles, sandpapers etc) that have this solution so it must be OK. But when and how do we document it when there is no PL? Is it this 60204-1 10.7.3 that I refer to?
I'm reading up on safety in control systems and have a few questions.
This is according to 13849-1.
I have never been involved with designing safety according to a risk analysis so this is just theoreticly questions.
I understand that the risk analysis is providing me with a PL and I must design the safety function according to this. For instance a magnetic switch on a door.
1. How about the emergency stop that is a complementary safety function? Do I get a PL for this or are emergency stops excluded from 13849-1 PL design?
2. I have heard and seen that some say that you have to design for atleast PL c. Where can I read this in a standard?
3. In the machine directive EN-60204-1 10.7.3 it says:
"Where a stop category 0 is suitable, the supply disconnecting device may
serve the function of emergency stop where:
- it is readily accessible to the operator and
- it is of the type descibed in 5.3.2 a),b),c) or d)
Where intended for emergency use, the suppy disconnecting device
shall meet the colour requirements of 10.2.1"
So this means that I can use the supply disconnecting device for emergency stop? How does this compare to the 13849-1? There is plenty of machines (drilles, sandpapers etc) that have this solution so it must be OK. But when and how do we document it when there is no PL? Is it this 60204-1 10.7.3 that I refer to?