Modifications to equipment earthing arrangements.

[Red to black]

Not so Lucien Re: generating plant : although I currently work in a nuclear associated industry.
I hear what you are saying, a thorough understanding of the system you are dealing with is essential, sadly this is often lacking by people whose ambition outweighs their ability

[Argus25]

Originally Posted by GrimJosef

It's the same (legal) reason that in some countries off-duty doctors walk past people having heart attacks. But my conscience would struggle with it.

That possibly happened one or twice in past history. It would be practically unheard of now. Most countries that have highly developed and evolved litigation systems (the developed world) have Good Samaritan laws, that protect anybody finding someone in trouble and helping them out, including doctors rendering emergency assistance, nobody I know in the medical field is shy to do it.

Which makes me think, if the safety of a vintage appliance can be practically improved by adding extra earthing, then just do it, it is a "good Samaritan" thing to do and will practically help others and even save a life maybe.

Imagine how you would feel if somebody got hurt or worse from a scenario with some vintage electronics (or any machinery) that could have been easily prevented with a simple modification, that wasn't done due to fear of litigation. If laws & regulations were not meant to be interpreted to some extent to suit circumstance, many lawyers would be out of work, because that is what they do.

[G8HQP Dave]

I have heard stories of nurses being told by their hospital that if someone collapses on the pavement outside they are not to render assistance because this would not be covered by the hospital insurance. Instead they should call for a paramedic. Most nurses I know would ignore this advice and do what they could.

In the UK we do have a habit of appointing to leadership at all levels people who believe fervently in box-ticking exercises, while denying that this is the case. Hence people who intervene without authorisation are as likely to be praised for their bravery or criticised for getting involved. In some cases brave people have been disciplined by their employer after a successful rescue. This is the atmosphere which causes some to be cautious about attempting to improve the safety of old electronic items.

[Radio Wrangler]

I remember the news stories of a group of firemen who were compelled to stand by near the top of a deep hole into which a woman had fallen. They hadn't received training on going down holes.

True it would have been tragic if any firemen had been injured/killed in making an attempt but it must have been terrible to have been held back. The woman later died. I seem to remember that her day-job was as a lawyer.

David

[GrimJosef]

Originally Posted by Argus25

... Most countries that have highly developed and evolved litigation systems (the developed world) have Good Samaritan laws, that protect anybody finding someone in trouble and helping them out, including doctors rendering emergency assistance, nobody I know in the medical field is shy to do it ...

We agree that a 'Good Samaritan' approach is morally right. Your country has laws which protect Good Samaritans. According to Wikipedia my country doesn't offer unconditional protection:

English law makes provision for the actions of 'good Samaritans,' unless their actions were grossly negligent or made a situation worse

(my bold).

I once arrived on the scene perhaps 10 minutes after a road accident. A motorcyclist was lying in the gutter. 10-20 other people were there, including a nurse from a care home. They said he had no pulse and wasn't breathing. I said we had to remove his helmet, make sure his airway was clear and start CPR. They said they hadn't removed his helmet because he might have a neck injury and they didn't want to risk making that worse. Before an argument could break out an ambulance arrived. They tried to resuscitate the motorcyclist, but they couldn't.

To be honest I don't think anyone was thinking about the legalities. They just didn't know what to do for the best. But if they had managed to save him at the expense of leaving him a paraplegic I don't know whether he might have sued anyone with insurance for the costs of his future care or, if he had sued them, whether they and their insurers would have been found liable.

Cheers,

GJ

[G8HQP Dave]

Some UK lawyers have adopted the school of thought 'there is no such thing as an accident'. They expect passers-by at an incident, or policemen in hot pursuit of a suspect, or soldiers on a battlefield, to calmly apply the same criteria as people debating the outcome afterwards in a court of law. That this is plainly daft seems not to be noticed by them. Of course, for every legal argument there is an opposing argument which is why they expect us to pay them so much for arguing on our behalf. It is not in their interests to have clarity. Fortunately in serious cases we can often rely on the jury to inject some common sense, provided that they are not too overawed by poor direction from the judge.

I remember two cases, although the details are hazy. One was a coastguard officer who was disciplined for rescuing someone (or was it a dog?) off a cliff. Another involved two PCSOs who watched someone drown because they had not been trained in water rescue techniques - I like to think that a real policeman would at least have had a go. I also vaguely recall all the crew of a lifeboat resigning because their cox had been disciplined for some minor alleged safety breach.

However, we have come a long way from changing mains leads so I suspect the Mods will reel us in!

[Junk Box Nick]

Originally Posted by G8HQP Dave

That this is plainly daft seems not to be noticed by them.

A lawyer earns their pay by arguing your corner. Their job is to argue their party's case by playing to all the strengths (flimsy ot otherwise) and ignoring the the rest, within the confines of the law. They might well find that on their next case they were in the opposite position and then be arguing the other way. It's doing the best for the client. They will be fully aware but that is not the job at hand!

The problem with most of the instances discussed in this thread is that none of them are black and white but in a litigious society the average Joe or Jane or business has a tendency to be far more cautious than was once the case. Thus we arrive at rules where only a technician with the appropriate qualification may wire up a mains plug.

[John10b]

What a very thought provoking thread, and as someone who has been responsible for writing risk assessments in an engineering environment I fully appreciate what has been said and the views expressed.
However I will still fit a three core mains cable to a vintage Radio or Record Player providing it is suitable to do so ( Transformer fitted etc ). I will take the view of making it “ safer” but not “safe”.
Cheers
John

[The Philpott]

'For display purposes only' perhaps being the catch-all vintage appliance version of the motor industry's 'For spares or repair', i think i would expand on it somewhat if i was in the position of selling something to Joe Public, probably something like:

'This device has been fitted with modern flex and has been used recently, but is a vintage/antique item and for this reason a guarantee of safety is neither given nor implied, and in your own interests it should be assessed by an industry professional before use'

To be frank, anybody that i would want to sell an old appliance to would be fully aware of the reasoning behind such a disclaimer, and as i have said before, PAT is not a very thorough chap, he just skims the surface!

Depending on what appliance was concerned i might shove in cautions about capacitors, asbestos, or whatever else was lurking inside. More concerned with my conscience than prosecution in that regard.

What a brilliant thread, by the way.

Dave

[Argus25]

Originally Posted by GrimJosef

English law makes provision for the actions of 'good Samaritans,' unless their actions were grossly negligent or made a situation worse

(my bold).

I was not aware that the English good Samaritan laws were so weak, that clearly needs fixing. They have simply been set up like that to create more potential work for lawyers.

My personal view on it is this:

If you were proposed a hypothetical question in a Philosophy class, that you are confronted with a decision to make. On one side of the coin there is an outcome that is the result of honorable and honest action, with clear intent to help another person or protect them from harm (like earthing a panel or chassis) and adds zero additional risks. On the other side of the coin, a risk remains of harm, if nothing is done. However the first choice breaks a rule or regulation. What do you do ?

Now nobody would want to suggest breaking the rules. However we all have a responsibility to recognize when the rules are defective and don't apply, until a later date, when they inevitably get amended.

So luckily we are all grownups and all know exactly what do.

It is only the culture of fear and threats of some kind, like litigation, that would stop anyone from doing the right thing.

Also, under the above circumstances even with the current over zealous litigation systems (which appear to primarily benefit the legal system & lawyers) I cannot imagine how, in the above situation, a person who acted in the correct manner could be found in any way at fault. In fact, a slick lawyer might argue it was negligent to do nothing, when in fact something simple could have been done to prevent problems.

The key here is, that the modifications (extra earthing) adds no additional risks. If it was some other decision, where other kinds of risks get added, then there is an "added risk level vs removed risk level" argument about the action for lawyers on each side to squabble over.

[Radio Wrangler]

Asimov was clearly a jump or two smarter than our legal systems.

How did it go? "No robot shall harm a human, nor through inaction allow a human to come to harm"

And then he milked it by writing a number of stories where there was no way to meet the law.

Damned if you do and damned if you don't.

David

[Argus25]

Originally Posted by Radio Wrangler

How did it go? "No robot shall harm a human, nor through inaction allow a human to come to harm"

And then he milked it by writing a number of stories where there was no way to meet the law.

David

I think though, these laws could be interpreted (like lawyers interpret law) that it was ok to harm a human being and still be inside the law, because the robot is a difference engine. To save 99 humans, one might have to die, if that were required to save them. In the end, the robots could only work for the greater good.

[Synchrodyne]

Returning to the original issue, let’s say a three-core power lead, inclusive of a protective earth, is retrofitted to a 1950s domestic radio receiver (of the AC-only type with double-wound power transformer) that originally came with just a two-core power lead.

On the face of it, the receiver is in a general sense now safer than it was originally. But is there any downside to this change?

Let’s say that the receiver also has the customary AM aerial and earth sockets, the latter connected directly to the chassis. And that the user’s manual notes that AM reception may be improved by connecting an “RF earth: to a rising cold water pipe, earth stake, etc. And that further, the user installs such an RF earth. Might this dual-earthing give rise to problems and potential hazards that did not arise with the original two-core power lead? Food for thought, I think….


Cheers,

[David G4EBT]

In the UK, for maybe fifty years or more, the 'rising cold water pipe' is plastic - not metal, and so is the mains gas pipe so neither would function as an 'RF Earth'. All internal pipework is cross bonded so as to be at the same potential and the only available earth in domestic premises is that at the ring main sockets. Unless of course anyone is minded to drive a copper stake into the ground and run a wire into the house. (Someone will have).

I always smile when reading old instructions on radios and in magazines which often stated: 'On no account connect an earth wire to a gas pipe as that could be extremely dangerous'. How's that then? Since the late 1950s many gas cookers, some gas fires and all central heating boilers have used mains electricity for ignition and control systems, and sometimes for illumination. Hopefully, those gas appliances (and hence, the gas pipework within the house), are all connected the earth.

As a matter of course, on any radio which has a built-in isolation transformer, I routinely fit a 3 core flex with the earth connected to the chassis. Can't think why I wouldn't do, or why it's seemingly such a contentious topic, which has morphed into 'good Samaritan' laws and conventions.

[Radio Wrangler]

That now depends on the form of earthing in the premises.

Bringing a real earth connection, without bonding, into a building with safety earth provided from the substation via a common earth/neutral conductor is dangerous. Such installations aren't always labelled, and no-one tells the householder that there are things he/she must not do.

multi-dimensional minefield!

David

[G8HQP Dave]

Originally Posted by Argus25

In fact, a slick lawyer might argue it was negligent to do nothing, when in fact something simple could have been done to prevent problems.

In France I believe that it can be an offence to do nothing. It could be that this is a side-effect of the Napoleonic law system, which basically says that everything is forbidden unless it is expressly permitted. Hence to allow people to help legally, you have to make it the law that they should help. On a French wireless website people could be debating exactly the opposite problem from us!

I always smile when reading old instructions on radios and in magazines which often stated: 'On no account connect an earth wire to a gas pipe as that could be extremely dangerous'. How's that then?

Sparking at a poor pipe joint or a crack? Old gas pipes may be cast iron. A leak can be dangerous; a leak with a spark as the pipe breaks could be catastrophic.

[Radio Wrangler]

Sparks exist quite naturally in the real world. Just walking across a carpet makes many. Man made fibre clothes etc. Gas leaks are just plain dangerous.

Having an electrical spark nearby might actually be safer.... starting a fire when otherwise there may be a build up of gas/air mixture and a large explosion.

It was my turn to host a committee meeting for the riding club and about half way through, the smokers needed a fag break. They didn't want to smoke in a non-smoker's house and it was pouring down outside, could they use the garage?

They were puffing away in the garage when someone noticed the trolley with the welding cylinders on it. Total panic was an understatement... Why didn't I tell them there were gas cylinders in there?

It took some doing to explain that 1) many welders smoked 2) My cylinders were turned off at their valves 3) when in use welding creates lots of sparks and can send them flying in all directions. You have to be careful with combustible materials in a garage. The gas equipment has to be absolutely flameproof. After changing cylinders etc, joints get leak tested with soapy water.

What I didn't tell them is that while mains gas is combustible, acetylene is of itself explosive. No oxygen required.

Underground gas pipe was not simply cast iron, it was malleable, bendable so as not to fracture easily. Joints and fittings were likely cast iron. Any leak will probably turn into a hazardous situation, so serious efforts are taken to prevent leaks.

The old advice about earths and gas pipes was panicky overreaction.

David

[Brigham]

The gas supply to gas/electric combination light fittings (much more common in N. America than here) always went via a porcelain and brass insulating fitting, to isolate the electrical part of the fitting from the gas mains.

[G6Tanuki]

Originally Posted by David G4EBT

In the UK, for maybe fifty years or more, the 'rising cold water pipe' is plastic - not metal, and so is the mains gas pipe so neither would function as an 'RF Earth'. All internal pipework is cross bonded so as to be at the same potential and the only available earth in domestic premises is that at the ring main sockets. Unless of course anyone is minded to drive a copper stake into the ground and run a wire into the house. (Someone will have).

Here, as like pretty much every rural consumer round here - we have "TT" supplied by the DNO from a 11KV transformer on a pole about 50 yards away.

Two un-insulated overhead conductors, supported by historic-looking brown porcelain insulators.

No "earth-bonding" of any pipework! instead we have - immediately after the meter - a trio of 100A 'B'-profile RCDs. The RCDs, and the earth-connections from all the sockets, are connected via a 4mm CSA conductor to a single earth-spike just outside the front porch.

[We don't have gas, and my water comes from a well-pump, so no 'water-main earth' either]

[richard.cs]

Originally Posted by Red to black

Been trying to stay out of this discussion so far
How many of us can say they are fully conversant with current safety standards as applied to consumer goods? not many I would wager.
How many of us are fully trained experts in law ? again not many.

I have the benefit of designing things to meet safety standards as part of my day job, sometimes for consumer use, sometimes industrial. I don't usually take sole responsibility for this, but it gives me a good overview of the requirements. Comparing things to existing "generally accepted as safe enough" products is very common and may form part of the evidence in the CE technical file. External test house testing is not required, but may be sensible if you either lack the experience or the equipment to do the testing internally. EMC is often an example of the latter, where the full test setup is big and expensive. In reality it is not just testing, much of the technical file is design evidence.

Originally Posted by GrimJosef

I once arrived on the scene perhaps 10 minutes after a road accident. A motorcyclist was lying in the gutter. 10-20 other people were there, including a nurse from a care home. They said he had no pulse and wasn't breathing. I said we had to remove his helmet, make sure his airway was clear and start CPR. They said they hadn't removed his helmet because he might have a neck injury and they didn't want to risk making that worse. Before an argument could break out an ambulance arrived. They tried to resuscitate the motorcyclist, but they couldn't.

I saw an interesting documentary on the TT paramedics last year, and one point they made is that they always remove helmets, they consider the risk to be low and justified. Two justifications were given that I remember, one that head injuries usually result in swelling and that removing it later (when it's stuck) is much more risky, and the more obvious one that if they're not breathing and you can't do CPR and/or clear their airway with the helmet on then you basically have a choice between life with a chance of spinal injury and death.


Coming back to the earthing question it's not always as clear cut as we might like. Let's come back to the class 0 heater with a metal body and poorly guarded element. It's not the kind of thing that would be commonly used outdoors, class 1 would be acceptable in a modern product. However, when designed it would probably have been used upstairs in a house with a timber floor and minimal indoor plumbing, likely few other appliances. Upstairs in a 1930s house was almost an earth-free location. Earthing the case and making it a class 1 does mitigate internal insulation failures, but means you have introduced a current return path that the designer did not envision when they made the choice not to put guards over the element. In that sense a new risk *has* been introduced (touching element and case now gives you a shock), though this increase is perhaps less significant when the appliance is operated in a modern house which has many more "earthy" things. Maybe it would have been better to provide reinforced insulation instead and come closer to class 2, or maybe fitting a 10 mA RCD plug to it is better than either. Or maybe you look at it, and decide that it's not too different from a toaster you can buy in Tesco after all.