WHO DOES THE EC FOR AN ASSEMBLY OF MACHINES?
Let’s take a practical example.
Take a die casting machine: The machine has safety doors and a safety control system that complies with standards. The machine is EC.
Now take a robot for extracting the part: Follow the installation manual and equip it with an enclosure in accordance with standards. The robot is EC.
Place the robot in front of the press.
The assembly is EC only if the emergency circuits are properly connected.
It often happens that both gates of the press can open, so the operator is able to touch the robot while it’s running.
And it’s enough to put some petrol in a tank and light it with a cigarette lighter.
They are perfectly safe if you keep them apart, but when you put them together you’ve made a bomb!
I have given you a example that’s easy to understand, but when you have to do the EC of an assembly, you must assess the areas of interaction between the machines, their intended use and also their unintended but conceivable use.
We must consider what happens in emergency situations. We must consider what happens during maintenance.
Once all these assessments have been made …. it isn’t enough just to affix the EC; one must reduce the risk to the absolute minimum. If that cannot be done, other measures must be taken.
When the risk is low and the areas have been protected with the proper sensors (you know. the ones classified with pla, b, c, d, e ….), then you look at the documentation.
There has to be a manual that summarises the use of the assembly, which then becomes part of the technical dossier.
The trouble is that it takes a lot of experience to make the assessments and a huge amount of time to read all the documentation for the machines.
Do you think that anyone can do it for you for free?
I really do not think so.
They’ll tell you that they do everything, but in reality they don’t do anything.
And what happens when there’s an accident?
The chickens come home to roost and everyone pays for their mistakes.
Everyone, from the manufacturer to the end customer, to the department manager.
Likewise the employer who wasn’t paying attention.
A tremendous disaster.
So what must be done?
We must rely on experienced manufacturers who know what must be done.
But often that is not enough.
We also need very experienced consultants to guide the people doing the certification so they find the right solutions.