General Machine Safety

kckku

Member
Join Date
Aug 2021
Location
Toronto
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62
We are buying some duplicate machines from overseas (one from Asia and one from Europe). Both of these machines don't have pneumatic lockouts, safety relays, dump valves, etc.

I honestly don't know how they have gotten away with this up until now. Their excuse so far has been that we already have these machines in our plant. To me this makes it worst meaning someone just bought these off the shelf.

I think at a minimum you would need a pneumatic lockout, some safety monitored relays to dump the air on an E-stop and kill the power for the conveyor motors.

Is this a common thing nowadays? Are companies still making machines without dump valves, lockouts, safety relays, etc.?
 
I've seen it plenty when someone purchases a machine used. Very rarely on new machines, but I don't see them purchased from overseas as often.



It's always POSSIBLE that for a given machine it's safer to not dump air, etc (if it is keeping something suspended, perhaps), but if there isn't even a safety relay that seems unlikely they've even considered it.


Unless the PLC is a fail-safe variant and you just didn't know? It's getting more and more seamless these days.
 
I've seen it plenty when someone purchases a machine used. Very rarely on new machines, but I don't see them purchased from overseas as often.



It's always POSSIBLE that for a given machine it's safer to not dump air, etc (if it is keeping something suspended, perhaps), but if there isn't even a safety relay that seems unlikely they've even considered it.


Unless the PLC is a fail-safe variant and you just didn't know? It's getting more and more seamless these days.

They are just using a standard Omron CJ2M PLC with CJ1W I/O cards. No safety relay or safety PLC that I can see in the schematics. One channel of the E-stop is used to power a relay with three normally open contacts. Each of these contacts are then wired to each of the conveyor motors to kill power.

The pneumatic circuit isn't even wired in to anything. It's just hand valve as shown in the pneumatic diagram. There's a big traverser on this machine so I would think they would want to dump air for this. The hand valve is behind a panel at the rear of the machine.
 
Almost all of the equipment that I've been involved with purchasing only comes with the most basic safety controls unless we specify something better in the contract.

However, all of the equipment that we buy has to be married into our production line and often the supplier really doesn't know what safety's will be needed.

At the end of the day it is our responsibility to make it safe, not the manufacture.
 
Almost all of the equipment that I've been involved with purchasing only comes with the most basic safety controls unless we specify something better in the contract.

However, all of the equipment that we buy has to be married into our production line and often the supplier really doesn't know what safety's will be needed.

At the end of the day it is our responsibility to make it safe, not the manufacture.
That can be taken care of early on between the finish of the mechanical design and the start of the electrical design with a risk assessment. Surprising how often this step gets skipped.
 
That can be taken care of early on between the finish of the mechanical design and the start of the electrical design with a risk assessment. Surprising how often this step gets skipped.

What's making this worst now is that we already have these machines in the plant. These were purchased years ago (probably without a risk assessment). Now people are going to start asking why.
 
What's making this worst now is that we already have these machines in the plant. These were purchased years ago (probably without a risk assessment). Now people are going to start asking why.

Right, that's going to be a lot of work to bring them up to latest specs. but its got to be done. A small percentage of the contract work I get involves safety upgrades either from equipment upgrades or the physical act of moving the equipment.
 
I believe that the trade agreement between EU and US has made the 2 ways of doing things equivalent.
That means that the machines from EU must have the EC declaration of conformity, unless they follow US standards which is unlikely.
The EC declaration of conformity is a legal document, it must state that the supplier considers the machine safe and that it follows relevant standards. The standards must be listed in the document. One standard that is always listed is the machinery directive. The machinery directive demands for example that there must be a risk assessment, and that a long list of specific regulations must be followed (affectionately known as EHSR - the Essential Health and Safety Requirements). The EHSR covers many aspects, including means of isolationg the machine from energy sources for maintenance purposes.

The machine vendor can claim that the machine is intended to be finished by someone else, who makes the machine safe and signs the EC declaration of conformity. But in that case he must provide an EC declaration of incorporation, and enough information that a 3rd party is made aware of the risks of the machine in its unfinished state.
If the machine is ready to run, has a control system, buttons for start and stop etc, then I dont think the machine vendor can get away with merely the EC declaration of incorporation.
It is illegal to sell a machine with neither an EC declaration of conformity or an EC declaration of incorporation.

In the EU, the customer has committed an illegal act if he has purchased and taken into operation a machine without making sure that it is safe, i.e made sure it has an EC declaration of conformity, studied and implemented all safety instructions for the machine etc..
 
Last edited:
I believe that the trade agreement between EU and US has made the 2 ways of doing things equivalent.
That means that the machines from EU must have the EC declaration of conformity, unless they follow US standards which is unlikely.
The EC declaration of conformity is a legal document, it must state that the supplier considers the machine safe and that it follows relevant standards. The standards must be listed in the document. One standard that is always listed is the machinery directive. The machinery directive demands for example that there must be a risk assessment, and that a long list of specific regulations must be followed (affectionately known as EHSR - the Essential Health and Safety Requirements). The EHSR covers many aspects, including means of isolationg the machine from energy sources for maintenance purposes.

The machine vendor can claim that the machine is intended to be finished by someone else, who makes the machine safe and signs the EC declaration of conformity. But in that case he must provide an EC declaration of incorporation, and enough information that a 3rd party is made aware of the risks of the machine in its unfinished state.
If the machine is ready to run, has a control system, buttons for start and stop etc, then I dont think the machine vendor can get away with merely the EC declaration of incorporation.
It is illegal to sell a machine with neither an EC declaration of conformity or an EC declaration of incorporation.

In the EU, the customer has committed an illegal act if he has purchased and taken into operation a machine without making sure that it is safe, i.e made sure it has an EC declaration of conformity, studied and implemented all safety instructions for the machine etc..

Thank you for this information.

I just heard from my colleague that our sister plant in France has taken delivery of the machine in question. The vendor is based in Belgium so I believe they must have to show the EC declaration of Conformity. This should be a easy ask I think for them to show. If they don't then we are all in trouble (both France and Canada).
 
to answer the question of how they got away with no safeties. it's called the grandfather clause. simply put, a machine built in the 1960's had little or no safety regulations. then let's say that in 1970, lock outs, safety relays and several other regulations went into effect. these regs only pertain to new equipment or in the process of being built. the 1960 machine does not have to meet these requirements, its already in production. but if the company modifies the machine any, they must bring it up to the new standards.

as i currently understand the rules, you bought used equipment that does not have these safety devices. It's up to your company to upgrade the system to the new regulations, it's NEW to your plant, so the rules apply.
if i am wrong, someone please correct me,
james
 
.

Is this a common thing nowadays? Are companies still making machines without dump valves, lockouts, safety relays, etc.?

Yes it is common.
If i don't specify what exactly i want to the OEM there will be at most an equivelant of a cat1 wired safety system. So pretty much nothing.
Even if i specify what i want 80% of the time they will not complete it. I mean even if i mark up the prints my self and send it back. It is just to much hassel if it not built into their production methods.
They will add some locking switches or pneumatic shutoff if i request, but they arent wired into safety relays.
Right now we are doing upgrades on machines strickly because asia cannot get certain parts.
Most of the customer spec parts around here, US calls out for manufactures that they wouldnt normally use anyways, at least in my industry.
 

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