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I've been asked to design a panel for 2x 3phase comressors and 2x 3phase vacuum pumps.
Non of the motors can start at the same time and between the 2, they have to run alternately. The vacuum pumps need to be wired so that if more vacuum is needed the other will start. Keep in mind that when the system is not being used the pumps will work alternately....
TIA
 
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davesparks

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What are you actually asking us here as I don't see any question in the OP, just a statement about something you are designing.
 
  • Thread Starter Thread Starter
  • #3
I'm asking for help on what i need to design this panel. To make them work alrernatly I can use a "flip flop relay". How do I incorporate the vacuum pumps to work alternately as well as standby if one cannot cope with what is required?
 
D

Deleted member 26818

Why would you want a system to run when it’s not in use?
 
  • Thread Starter Thread Starter
  • #5
What I meant was after it has been used.... before it is used again. They use the vacuum and pressure for different reasons in the lab. If they start at the same time the current spike is very high.
 
So what you are saying if the compressors are running the vacuum pumps cannot start and visa versa. With the vacuum pumps only one can be started initially but there is a facility for the second to kick in if required.
 
  • Thread Starter Thread Starter
  • #7
Yes, but after each cycle the vacuum pumps will start alternatively. So vacuum 1 will start and if required vacuum 2 will start. The next time vacuum is required vacuum 2 will start and if more vacuum is needed then vacuum 1 will start
 
D

Deleted member 26818

I think, knowing the use the vacuum is going to be for could help.
Is the vacuum to be used as fume extract?
Is it to vacuum liquid, will there be a catch tank?
Is it to be distributed?
Is it for a delivery system?
Is it to hold something in place?
Is it to be used for vacuum packaging?
 
  • Thread Starter Thread Starter
  • #9
This is what i have come up with and it will work. However, they don't want the timer to be used. Instead, they want me to use 2 pressure switches

1550751918175-552723564.jpg
 
B

Bobster

How are you going to complying with the CE directive and EN60204-1 to start with?
 
Rob - I can see the need for compliance with EN60204-1 but if he built the system, bit of a long shot from what we've seen thus far, with ce marked products is there further requirement for ce certification?

I've never heard of the necessity for logic system built with a plc or a few relays.
 
B

Bobster

Rob - I can see the need for compliance with EN60204-1 but if he built the system, bit of a long shot from what we've seen thus far, with ce marked products is there further requirement for ce certification?

I've never heard of the necessity for logic system built with a plc or a few relays.
Yes anything built like that needs to fill CE requirments.

Not got time into going over it now but take a look at this:

Conformity assessment - Work equipment and machinery - http://www.hse.gov.uk/work-equipment-machinery/conformity.htm
 
I'm still surprised because I know that people who custom build control panels have too but you can buy ce marked push button assemblies etc.

I know someone who installs siemens gear, check out there sirius range to see what I'm talking about, and he never mentioned it when we chatted about the technicalities of the subject nor was there any comments on the siemens forums.

I posted a question on there forum so I guess I'll see soon.
 

davesparks

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I'm still surprised because I know that people who custom build control panels have too but you can buy ce marked push button assemblies etc.
n.
Just using CE marked components doesn't automatically mean that you have built something compliant.
 
OK maybe an example would help.

If I had a lv commercial installation using all schneider gear with a key switch controlling an acti 9 relay controlling lights. All wiring installed to bs7671. Do I need to worry about ce certification?
 

netblindpaul

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OK maybe an example would help.

If I had a lv commercial installation using all schneider gear with a key switch controlling an acti 9 relay controlling lights. All wiring installed to bs7671. Do I need to worry about ce certification?
If this is a stand alone control panel, then yes, and BS 7671 would not be the relevant standard. If it is for lighting it would be the EN 61439 series, and you must CE mark in accordance with the Low Voltage Directive.
If it is to control machinery then the design and build standard would be EN 60204-1 (for general machinery, there are a couple of specific machine types that are outside this).
Using all CE marked components does not make the assembly CE marked.
I can take you through every reason if you like, but we'll be here a very long time, and I'm off to China Saturday for a few weeks, to advise a Chinese machinery builder on CE marking of their machinery and electrical panels.
I do much more of this now than I do electrical works, as my background is in machinery, and I used to do this before redundancy and self-employment.
What Rob has said is correct.

If you are designing and building electrical panels, there is a lot more involved, as the panel becomes a product in its own right, and that must be CE marked.

If it is controlling machinery, then the assembly of panel and machine must comply with the Machinery Directive.

This is the same concept as when you mix and match MCB's in a distribution board, like it or not, when you do that, you become the manufacturer of the assembly in the eyes of the law.

Oh, and as of the end of March no matter what happens, the only thing that changes will be CE being becoming UKCA marking for the UK market.
 

davesparks

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If this is a stand alone control panel, then yes, and BS 7671 would not be the relevant standard.
Is there a simple guide available as to what does/doesn't require CE marking?

Being required to CE mark a single relay in an enclosure controlling lights seems to be over the top and somewhat unenforceable.
 
Is there a simple guide available as to what does/doesn't require CE marking?

Being required to CE mark a single relay in an enclosure controlling lights seems to be over the top and somewhat unenforceable.
It can be tricky to know what applies but the using the relay example, if you put the bits together for yourself for use in your own premises then no CE mark is needed. I'd apply that if you did a job for a customer who, for practical purposes, might have bought the parts on your advice and you fit them. If you put the relay in a box and sold it on Amazon as a lighting contactor then it would need certification.

From the UK government guidance..

Using electrical equipment on your own premises
Electrical equipment that is intended for use by you in your own premises is controlled by the Electrical Equipment (Safety) Regulations 1994. Such equipment must satisfy the safety requirements of the regulations, but need not have CE marking.

However, should you subsequently decide to supply the equipment - eg by selling it or hiring it out - it will be subject to the relevant provisions of the regulations, including the CE marking requirements.
 

netblindpaul

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It can be tricky to know what applies but the using the relay example, if you put the bits together for yourself for use in your own premises then no CE mark is needed. I'd apply that if you did a job for a customer who, for practical purposes, might have bought the parts on your advice and you fit them. If you put the relay in a box and sold it on Amazon as a lighting contactor then it would need certification.

From the UK government guidance..

Using electrical equipment on your own premises
Electrical equipment that is intended for use by you in your own premises is controlled by the Electrical Equipment (Safety) Regulations 1994. Such equipment must satisfy the safety requirements of the regulations, but need not have CE marking.

However, should you subsequently decide to supply the equipment - eg by selling it or hiring it out - it will be subject to the relevant provisions of the regulations, including the CE marking requirements.
Just realise that this caveat does not apply to the Machinery Directive, and that includes any electrical panels controlling the machinery.
Also, forgot, if the company changes hands then there is the chance that that would be looked on as selling the equipment.
Whilst electrical equipment doesn't have to bear the CE mark, it still has to comply as if it did.
The mark is simply the last step in the process, which starts as soon as a design begins.
 
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Refurbished and modified machinery - Work equipment and machinery - http://www.hse.gov.uk/work-equipment-machinery/refurbished-modified-machinery.htm

This page say something about "existing products which are so substantially modified as to be considered new"

I think the simple example I gave would be fine because the products are being used exactly as intended and the switch can be fixed to a wall with cables ran in conduit to them the relay is din rail mounted.

Not sure though.

Also to make the example simple I used only one manufacturers equipment. If you make a control panel with all siemens gear they have a tool that helps with ce certification as well but there seems to be requirements beyond their tool.

Thanks for the information so far!
 
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netblindpaul

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Is there a simple guide available as to what does/doesn't require CE marking?

Being required to CE mark a single relay in an enclosure controlling lights seems to be over the top and somewhat unenforceable.
There is no simple guide unfortunately, but if you are placing an assembly of products on the market for sale, rental hire etc in the course of a business or to be used in the course of a business, then it must comply with the relevant product safety laws.
A DOL starter must comply with the LVD, and must be CE marked as a product.
Enforcement is a mute point, there is little, which is why we see so many dangerous white goods, phone chargers etc which catch fire being on sale.
 

netblindpaul

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Refurbished and modified machinery - Work equipment and machinery - http://www.hse.gov.uk/work-equipment-machinery/refurbished-modified-machinery.htm

This page say something about "existing products which are so substantially modified as to be considered new"

I think the simple example I gave would be fine because the products are being used exactly as intended and the switch can be fixed to a wall with cables ran in conduit to them the relay is din rail mounted.

Not sure though.

Also to make the example simple I used only one manufacturers equipment. If you make a control panel with all siemens gear they have a tool that helps with ce certification as well but there seems to be requirements beyond their tool.

Thanks for the information so far!
If you modify something then you make a new product, unless it does exactly the same thing. but, remember, for example, that some products require type testing to meet the standard, if you modify such as to breach the type test, then that would be significant.
It's nothing to do with sticking with one manufacturer, unless you are talking about compliance with the EN 61439 series, or other equipment which is type tested.

You don't "need" a tool to CE mark, it can be done long hand. There is a LOT more to machinery controls, and designing and building electrical panels than is involved in BS 7671, and if you think that is expensive, then think again, most of the standards that need to be complied with to take a presumption of conformity cost 4 - 5 times what BS 7671 does.

If you go and fix a machine, and you take out a Siemens relay from a safety circuit, and fit a Schneider one, because that is your van stock, then you have invalidated the CE mark on the equipment and absolved the manufacturer of any liability. You then become liable as the manufacturer should your modification result in loss, injury or death. The same would apply to an e-stop button, or a safety door switch, door interlock etc.
It's a minefield, because you are straying into product law, and product liability, how many of you carry product liability insurance for products you manufacture?
 
netblindpaul - you said about enforcement for white goods, I'm more interested in automation integration using plc's or just switches, signalling lights and relays. It's starting to seem there's not much enforcement there either.

Do hse have people capable of inspecting and making decisions on this type of thing?
 
If you modify something then you make a new product, unless it does exactly the same thing. but, remember, for example, that some products require type testing to meet the standard, if you modify such as to breach the type test, then that would be significant.
It's nothing to do with sticking with one manufacturer, unless you are talking about compliance with the EN 61439 series, or other equipment which is type tested.

You don't "need" a tool to CE mark, it can be done long hand. There is a LOT more to machinery controls, and designing and building electrical panels than is involved in BS 7671, and if you think that is expensive, then think again, most of the standards that need to be complied with to take a presumption of conformity cost 4 - 5 times what BS 7671 does.

If you go and fix a machine, and you take out a Siemens relay from a safety circuit, and fit a Schneider one, because that is your van stock, then you have invalidated the CE mark on the equipment and absolved the manufacturer of any liability. You then become liable as the manufacturer should your modification result in loss, injury or death. The same would apply to an e-stop button, or a safety door switch, door interlock etc.
It's a minefield, because you are straying into product law, and product liability, how many of you carry product liability insurance for products you manufacture?
Yeah I guess that's reasonable. I'd like to know how far I could push my simple example though?

Since now I've said that the switch is surface mounted on a wall and the relay is din rail mounted can I do that without any further efforts to achieve compliance?

My insurance won't cover machine building no.
 

davesparks

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Is there anything we do which is not putting an assembly of products on the market?

Does installing a grid switch count as putting an assembly on the market or does the manufacturer of the grid switch system take responsibility as they designed it all to work together?

In which case where would we stand fitting a GET switch onto a BG pattress put us?

I realise these are possibly slightly ridiculous questions, but I'm just trying to get an idea of how far this goes.
 

netblindpaul

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netblindpaul - you said about enforcement for white goods, I'm more interested in automation integration using plc's or just switches, signalling lights and relays. It's starting to seem there's not much enforcement there either.

Do hse have people capable of inspecting and making decisions on this type of thing?
Oh yes they blinking do, and they know the science, engineering and technology behind it too!
They have a whole laboratory full of engineers and scientists who are specialists in their field.
They will know the law, the standards, and the fundamental engineering and science behind what is needed.
They tend only to roll these people out when deaths or major incidents are involved.
The HSE "inspector" that turns up at a factory gate un-announced will likely not know the details, but, they will know how to get a specialist involved if necessary.

However, there is little resource to police this, the insurance companies will be doing this without companies realising it, because unless they are fully compliant with the law, their insurance policy is null and void, it's in the small print.
It's often ignored until there is an issue...
You know what the old saying is "if you think safety is expensive try having an accident".
 

netblindpaul

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Arms
Is there anything we do which is not putting an assembly of products on the market?

Does installing a grid switch count as putting an assembly on the market or does the manufacturer of the grid switch system take responsibility as they designed it all to work together?

In which case where would we stand fitting a GET switch onto a BG pattress put us?

I realise these are possibly slightly ridiculous questions, but I'm just trying to get an idea of how far this goes.
An MK grid switch assembly is covered by MK, if it is done in accordance with their instructions.
Devices such as a GET light switch and a BG patress back box, are designed and the standards are written in such a way that they can be assembled in an ad-hoc manner, as long as they fit together correctly.
Metal clad sockets and switches often have "custom" back boxes and one make of socket won't fit another makes back box correctly, then the product law would kick in, and you would be in breach of it, because they were not designed to be as one assembly.
 
Is there anything we do which is not putting an assembly of products on the market?

Does installing a grid switch count as putting an assembly on the market or does the manufacturer of the grid switch system take responsibility as they designed it all to work together?

In which case where would we stand fitting a GET switch onto a BG pattress put us?

I realise these are possibly slightly ridiculous questions, but I'm just trying to get an idea of how far this goes.
"I'm just trying to get an idea of how far this goes"

Me too seems we could come close in commercial installations fairly regularly
 
An MK grid switch assembly is covered by MK, if it is done in accordance with their instructions.
Devices such as a GET light switch and a BG patress back box, are designed and the standards are written in such a way that they can be assembled in an ad-hoc manner, as long as they fit together correctly.
Metal clad sockets and switches often have "custom" back boxes and one make of socket won't fit another makes back box correctly, then the product law would kick in, and you would be in breach of it, because they were not designed to be as one assembly.
From what your saying it sounds like if we're following manufacturers instructions and not building a machine it's fine.
 

netblindpaul

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From what your saying it sounds like if we're following manufacturers instructions and not building a machine it's fine.
Unless you are doing the work in the course of a business, and it is to be used outside your business premises.
So in the course of your business, if you buy a Schneider panel and put a load of Schnieder control gear in it and a Schneider PLC to control the lighting in a customers premises, it must be CE marked to the LVD by you.
If it's real DIY at home then it doesn't matter until you sell it, in which case it probably will even if it is to another DIY'er and it's already 2nd hand.
 

netblindpaul

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"I'm just trying to get an idea of how far this goes"

Me too seems we could come close in commercial installations fairly regularly
Yes you could, if you put a box of bits together without thought, for example a lighting panel, or a control panel for some extract fans, then you must follow the procedure and CE mark it, lighting would be to the LVD, and fans to the MD, Air con panels, MD, LEV panels MD, Heating panels, could be either depending on the heating system.
 
Yes you could, if you put a box of bits together without thought, for example a lighting panel, or a control panel for some extract fans, then you must follow the procedure and CE mark it, lighting would be to the LVD, and fans to the MD, Air con panels, MD, LEV panels MD, Heating panels, could be either depending on the heating system.
To be honest I think my insurance doesn't cover any of that and I don't want to expose myself to the liability. Ce marking has fines attached if you c**k it up.

I think my focus, and same for most people here, should be avoiding the whole ce business.
 

netblindpaul

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Avoidance is up to you, but remember, lots of products are already CE marked, and modifications to them eliminate that and put the "person" modifying them in the firing line as the manufacturer.
This includes machinery repairs.
Because I have always done this sort of work, when I went self-employed, well 1 person ltd co with my own customer base rather than doing labour only subbying, I went looking for insurance, and found that my core business of machinery repairs and upgrades etc. was excluded from most insurance policies offered to electrical contractors, it was a surprise how many policies when you read the small print excluded 3ph work too.
We probably pay as much a month for insurance to do the consulting, machinery repairs & modifications, design & provision of electrical panels etc. and general electrical contracting and maintenance (7671 stuff) as many of you do in a year.
There is still stuff on the consulting side that I can't do for people because I know I'm not insured, validation of safety software under IEC 62061 for example, I've also not got enough experience in all the possible PLC makes to put myself forward as an expert to do the safety training on the makes, to be competent to do the validation.
This is one area where HSE have even issued guidance on competency, and it is quite an eye opener.
I will eventually drop off the contracting stuff, but it makes so little difference in the cost of the policy it's handy to keep it there because if I do a job for friends or family then I'm still covered.

Remember, we've not even touched on COMAH site stuff, IEC 61508, chemical process plants and the like. That's just as critical, and changes there could cause major issues, normally in these environments they have change control mechanisms in place.
Though smaller operators may not be so careful, and could land a contractor in trouble.
 
Avoidance is up to you, but remember, lots of products are already CE marked, and modifications to them eliminate that and put the "person" modifying them in the firing line as the manufacturer.
This includes machinery repairs.
Because I have always done this sort of work, when I went self-employed, well 1 person ltd co with my own customer base rather than doing labour only subbying, I went looking for insurance, and found that my core business of machinery repairs and upgrades etc. was excluded from most insurance policies offered to electrical contractors, it was a surprise how many policies when you read the small print excluded 3ph work too.
We probably pay as much a month for insurance to do the consulting, machinery repairs & modifications, design & provision of electrical panels etc. and general electrical contracting and maintenance (7671 stuff) as many of you do in a year.
There is still stuff on the consulting side that I can't do for people because I know I'm not insured, validation of safety software under IEC 62061 for example, I've also not got enough experience in all the possible PLC makes to put myself forward as an expert to do the safety training on the makes, to be competent to do the validation.
This is one area where HSE have even issued guidance on competency, and it is quite an eye opener.
I will eventually drop off the contracting stuff, but it makes so little difference in the cost of the policy it's handy to keep it there because if I do a job for friends or family then I'm still covered.

Remember, we've not even touched on COMAH site stuff, IEC 61508, chemical process plants and the like. That's just as critical, and changes there could cause major issues, normally in these environments they have change control mechanisms in place.
Though smaller operators may not be so careful, and could land a contractor in trouble.
"Though smaller operators may not be so careful, and could land a contractor in trouble"
I'm pretty sure ignoring most of what you say is normal practice. How can one avoid the bs?

Also you gave the example of me making a lighting system using all schneider gear saying that I'd have to mark it. There seems to be slightly different rules for fixed installations something we haven't covered in this chat. I'm new to this but watching a video from Queen University. The lecture says for fixed installations "you don't ce mark it, you don't provide a declaration of conformity but it has to comply with the protection requirements".

Those are his words not mine. I'm not sure why he says it.
8 minutes into this video he says it.
 

netblindpaul

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That video is entitled EMC Directive, we’ve not even got as far as discussing this yet.
What you state is correct wrt a fixed installation under BS7671, as an assembly of CE marked components.
However the components that are used to put the installation together are not exempt from anything.
 

David Prosser

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How are you going to complying with the CE directive and EN60204-1 to start with?
I thin
If this is a stand alone control panel, then yes, and BS 7671 would not be the relevant standard. If it is for lighting it would be the EN 61439 series, and you must CE mark in accordance with the Low Voltage Directive.
If it is to control machinery then the design and build standard would be EN 60204-1 (for general machinery, there are a couple of specific machine types that are outside this).
Using all CE marked components does not make the assembly CE marked.
I can take you through every reason if you like, but we'll be here a very long time, and I'm off to China Saturday for a few weeks, to advise a Chinese machinery builder on CE marking of their machinery and electrical panels.
I do much more of this now than I do electrical works, as my background is in machinery, and I used to do this before redundancy and self-employment.
What Rob has said is correct.

If you are designing and building electrical panels, there is a lot more involved, as the panel becomes a product in its own right, and that must be CE marked.

If it is controlling machinery, then the assembly of panel and machine must comply with the Machinery Directive.

This is the same concept as when you mix and match MCB's in a distribution board, like it or not, when you do that, you become the manufacturer of the assembly in the eyes of the law.

Oh, and as of the end of March no matter what happens, the only thing that changes will be CE being becoming UKCA marking for the UK market.

It's not a stand alone control panel though. It a key switch instead of a normal light switch that switches all the lighting on through a relay in the distribution board.
 
I thin



It's not a stand alone control panel though. It a key switch instead of a normal light switch that switches all the lighting on through a relay in the distribution board.
I checked with stone-emc.co.uk, who I'd recommend for all your emc/ce work needing done, and they say no ce mark needed nor pre-compliance emc testing. He says the same as the guy in the video. What's required is good engineering practice and to follow manufacturer's instructions.
That goes for the simplest example and controlling the lights with a plc.
It's different if your equipment isn't fixed or you're selling it as an end user product.
Also the siemens forums are empty of comments on this because no one is doing it. They are, however, full of questions on how to correctly follow the manufacturer instructions.
 
We never got as far as EMCD, I was only going through LVD & MD, how did this get to EMCD?
When does emcd apply? Have I lost the plot? You were talking about ce certification? Does ce certification not always include emc?
Also maintaining compliance with emc directive is actually required in all examples given? It's just done by good engineering practice and following manufacturers instructions. Testing is not normally required though it may be, it would seem.
 

netblindpaul

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I thin



It's not a stand alone control panel though. It a key switch instead of a normal light switch that switches all the lighting on through a relay in the distribution board.
That depends on what it is, if you put it together and fit it, it's a product, which means it must meet the LVD.

I am struggling to understand why this thread has moved from LVD compliance on to EMC compliance.
The requirements of the two directives are totally different.
 
That depends on what it is, if you put it together and fit it, it's a product, which means it must meet the LVD.

I am struggling to understand why this thread has moved from LVD compliance on to EMC compliance.
The requirements of the two directives are totally different.
You're right it must be in compliance with lvd. This topic has included other factors as any conversation in this area should

Can I ask the name of your company?
 

spark 68

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Interesting and fascinating discussion about CE marking and EN standards as ever chaps :) however the OPs location is given as South Africa, I don't think any of these directives apply to him :cool:, no doubt similar national/international equivalent standards do though. :rolleyes:
 
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