This discussion has been locked.

You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Machinery directive

Afternoon All,

I am looking for some direction. I work as an engineer for a automotive transmission company. We have recently invested in a loaded test cell for testing both end-of-line and development gearboxes. We are now in the commissioning phase of the project and have just started learning about the machinery directive and requirement to have a CE marked machine.

We understand that to be able to use this rig in the workplace under the PUWER regs, the starting point is to have the machine CE marked with a corresponding declaration of conformity. Our rig supplier has indicated that a declaration of incorporation will be issued as the room that the rig is housed forms part of the 'guarding' around the rig and thus the supplier has deemed the supply of the rig to be incomplete.

The supplier has manufactured many electrical & mechanical sub-assemblies which have then been assembled in our room by the supplier. Since the supplier has classed the rig as incomplete we are left to carry out the final CE marking. I think this is a little strange as we are not rig manufacturers and I am also not aware of discussions as to the suitability of the room structure to perform as a suitable 'guard'

The rig is to test gearboxes for which we have designed & manufactured the gearbox and driveshafts that will link to the rig. The rig could be considered incomplete until the gearbox & driveshafts have been fitted prior to the test but that would mean we have to CE mark for all iterations of gearbox which I feel goes against what the machine directive has been conceived? An analogy to this is buying a CE marking milling machine and having to reassess it the minute a lump of material is placed in the vice and a cutter inserted into the chuck?

Considering the electrical aspects. The rig consists of a control system linked to a number of high power inverter drives. When quizzed about the machine directive and associated EMC testing we are informed that the drives are individually CE marked and therefore EMC testing of the complete rig system is 'not a good idea' and not required which immediately rang alarm bells.

Can anyone provide any pointers as to how we get the rig fully operation in a H&S compliant way?

Parents

0 Roger B over 4 years ago

The first and not very helpful comment is that this should have been resolved during the specification and design phases.

I have made similar CE assessments for an assembly of components from different suppliers and it is not too arduous. Here are a few thoughts as I don’t know how far along you are.

The basic requirements are on the HSE website here:

https://www.hse.gov.uk/work-equipment-machinery/new-machinery.htm

There is also some good guidance downloadable here:

https://ec.europa.eu/docsroom/documents/38022

Firstly you need to determine that what you have comes into the scope of the machinery directive (I believe it does) and that it is not in a special category, Annex IV, that requires certification by a Notified Body (I don’t think that it is).

You then need to go through Annex 1, ‘Essential health and safety requirements relating to the design and construction of machinery ‘ and determine what is relevant in your case.

This probably covers a lot of your risks:
1.3 Protection against mechanical hazards
1.3.1 §206 Stability
1.3.2 §207 Break-up during operation
1.3.3 §208 Falling or ejected objects
1.3.4 §209 Sharp edges and angles and rough surfaces
1.3.5 §210 Combined machinery
1.3.6 §211 Variations in operating conditions
1.3.7 §212 Moving parts
1.3.8.1 §213 Moving transmission parts
1.3.8.2 §214 Moving parts involved in the process
1.3.9 §215 Uncontrolled movements

You need to discuss the Declaration of Incorporation with the rig supplier to determine what they are actually certifying and what information they are supplying. There should certainly be operating instructions containing hazard warnings and requirements for safe operation.

You should end up with a list of hazards and what has been done to mitigate them, for example:

1) Parts ejected during failure of the gearbox under test-

Determine the maximum energy of the ejected parts (mass, rotational speed) and the energy absorbing capability of the containment structure. An xx cm thick concrete wall will withstand yy joules over an area of zz cm2.

Ensure that there are no exposed cables or pipes in the likely impact zones.

2) Entanglement in rotating components-

Interlocked guards with an assessment of the control system integrity required (EN 13849)

Door interlocks with a search and arm system to ensure no one remains in the test cell when the drives are started, again with a control system assessment.

EMC is unlikely to be a problem if the various drives and components have been installed according to the manufacturer’s instructions regarding, screening, grounding, etc. The actual requirements are that the equipment should not interfere with or be interfered with by other equipment. There also needs to be a system in place for resolving any problems that may occur. This can be dealt with in a quite pragmatic way. Are nearby computers affected? Do the lights dim when it starts? Do the drives start when someone makes a call on a mobile phone? Does it upset the radio in the coffee room? Most of the tests and levels in the various standards are to deal with devices which may be moved around into different environments not for fixed single installations.
Cancel
Vote Up 0 Vote Down

Cancel

Reply

0 Roger B over 4 years ago

The first and not very helpful comment is that this should have been resolved during the specification and design phases.

I have made similar CE assessments for an assembly of components from different suppliers and it is not too arduous. Here are a few thoughts as I don’t know how far along you are.

The basic requirements are on the HSE website here:

https://www.hse.gov.uk/work-equipment-machinery/new-machinery.htm

There is also some good guidance downloadable here:

https://ec.europa.eu/docsroom/documents/38022

Firstly you need to determine that what you have comes into the scope of the machinery directive (I believe it does) and that it is not in a special category, Annex IV, that requires certification by a Notified Body (I don’t think that it is).

You then need to go through Annex 1, ‘Essential health and safety requirements relating to the design and construction of machinery ‘ and determine what is relevant in your case.

This probably covers a lot of your risks:
1.3 Protection against mechanical hazards
1.3.1 §206 Stability
1.3.2 §207 Break-up during operation
1.3.3 §208 Falling or ejected objects
1.3.4 §209 Sharp edges and angles and rough surfaces
1.3.5 §210 Combined machinery
1.3.6 §211 Variations in operating conditions
1.3.7 §212 Moving parts
1.3.8.1 §213 Moving transmission parts
1.3.8.2 §214 Moving parts involved in the process
1.3.9 §215 Uncontrolled movements

You need to discuss the Declaration of Incorporation with the rig supplier to determine what they are actually certifying and what information they are supplying. There should certainly be operating instructions containing hazard warnings and requirements for safe operation.

You should end up with a list of hazards and what has been done to mitigate them, for example:

1) Parts ejected during failure of the gearbox under test-

Determine the maximum energy of the ejected parts (mass, rotational speed) and the energy absorbing capability of the containment structure. An xx cm thick concrete wall will withstand yy joules over an area of zz cm2.

Ensure that there are no exposed cables or pipes in the likely impact zones.

2) Entanglement in rotating components-

Interlocked guards with an assessment of the control system integrity required (EN 13849)

Door interlocks with a search and arm system to ensure no one remains in the test cell when the drives are started, again with a control system assessment.

EMC is unlikely to be a problem if the various drives and components have been installed according to the manufacturer’s instructions regarding, screening, grounding, etc. The actual requirements are that the equipment should not interfere with or be interfered with by other equipment. There also needs to be a system in place for resolving any problems that may occur. This can be dealt with in a quite pragmatic way. Are nearby computers affected? Do the lights dim when it starts? Do the drives start when someone makes a call on a mobile phone? Does it upset the radio in the coffee room? Most of the tests and levels in the various standards are to deal with devices which may be moved around into different environments not for fixed single installations.
Cancel
Vote Up 0 Vote Down

Cancel

Children

No Data

Machinery directive

Community Rules & Guidelines