110V vs 230V - a dumb question?

The post you dug up is 8 years old!
The "English" RCDs you speak of are now to an EN number now so are the same in all EN countries. For additional protection against direct contact only non-delayed models are allowed with a maximum trip current of 30mA.
I'm not sure where you get the idea of 230v being banned, it is one of the risks which needs to be assessed when specifying equipment yes but banned no.
We tend to use ceeform blue sockets in industrial environments where 230v is required.
 
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A very old post and since then rules have changed.
You can get RCD protection on 110 volt (55-0-55) supplies but even without from a large transformer with twin pole 16 amp MCB's on the output it is in the main safer.

However with yellow bricks used to allow the use of 110 volt tools in sites without a proper 110 volt supply the fire risk likely exceeds the shock risk. Unfortunately one often gets a yellow brick with a over current trip on the incomer only often rated at 13A this means with an earth fault of 54 amp without tripping the incomer and 1.5mm² attic flex will not take 54 amp. Use of cable plugged into cable means a scaffold pole can and has damaged a cable without any overload tripping and caused a fire.

411.8.3 Requirements for fault protection
Fault protection by automatic disconnection of supply shall be provided by means of an overcurrent protective device in each line conductor or by an RCD. and all exposed-conductive-parts of the reduced low voltage system
shall be connected to Earth. The earth fault loop impedance at every point of utilisation, including socket-outlets, shall be such that the disconnection time does not exceed 5 s.

This clearly outlaws the use of the yellow brick but I still see them on sites all over the place.

704.410.3.10 A circuit supplying a socket-outlet with a rated current up to and including, 32 A and any other circuit supplying hand-held electrical equipment with rated current up to and including 32A shall be protected by:
(i) reduced low voltage (Regulation 411.8 ). or
(ii) automatic disconnection of supply (Section 411) with additional protection provided by an RCD having the characteristics specified in Regulation 415.1.1, or
(iii) electrical separation of circuits (Section 413), each socket-outlet and item of hand-held electrical equipment being supplied by an individual transformer or by a separate winding of a transformer, or
(iv) SELV or PELV (Section 414).
Where electrical separation is used special attention should be paid to the requirements of Regulation 413.3.4.
NOTE 1: The reduced low voltage system is strongly preferred for the supply to portable hand lamps for general use and portable hand tools and local lighting up to 2 kW.
NOTE 2: the SELV system is strongly preferred for portable hand lamps in confined or damp locations.

This means you don't need to use 110 volt where there is RCD protection or where you have used isolation transformers. It was even before 2008 common to see the blue brick to step up supplies where the item was not available in a 110 version.

So what is the problem? Simple risk assessment and you can show how 230 volt is not only safer but allowed.
 
Looks like I won the golden spade.
I just rely on workmates who had been there before and asked why I put angle grinders on the materials list. I wouldn't be able to use them. No 230V permit, no hot work permit, no permission to change the disk once it is used. Hidden portable distribution box to obtain 230V illegally. Changing of Motors to 110V versions from the US. Yellow CEE plugs everywhere. Hand tools burnt while trying to run them on 110V in desperation, not recommended. 400m of cable drums to get 230V from the site office burns them too, voltage loss too high. HSE banning you from site if they catch you doing that. Swearing at Wikipedia stating the UK as 230V country. The prohibition is real. I'll report after seeing and believing myself.
I could imagine that it is not taken very serious on small sites. But on the large ones with a permanent HSE department on site you cannot tie your shoes without being watched through camera equipped binoculars.
 
110V is far safer, and in an environment like a construction site, I fully support it's use.

How much work do you do on British construction sites? If it's not a lot, surely you could arrage for a local tool hire company to drop a 110V grinder off on site for you. It'll save time messing about trying to lash up some dodgy 230V supply, not to mention creating a hazard for the other contractors working on site, and save you from threats of being kicked off site etc.

Whilst many people maon about sites being H&S mad, they seem to forget it is purely for their own protection. Whilst it can sometimes a bit inconvenient, I know at the end of every day I'm going home to my family alive and with all my limbs attatched.
 
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I don't get the logic. Everything above 50V without RCD is potentially lethal. Why don't you go to 24VDC. That is even safer. You don't even need a RCD. Simple circuit breakers are sufficient. Safe to touch.

The HSE industry is a giant job and money machine. Good for those who couldn't get a proper job. They found their biotope in anglo saxon countries. If I walk home safely it is because myself and those around me took care.
 
The 110V used on building sites is a split phase supply, so you have 55V to earth on each phase, which is going to drastically reduce the shock (if any at all) received from a piece of faulty or damaged equipment.

24V would require HUGE cables for a run of more than a couple of meters due to volts drop.

Whilst it would unarguably be much safer, there has to be a trade off with practicallity, and a 110V site supply seems to be the happy medium.

I was working on a medium sized site in Leeds where a scaffolder droped a tube whilst striking a scaffold. It hit a chap three floors below on the head. I'm sure he was being careful doing whatever he was doing, but had he not been wearing his hard hat like those nasty "HSE" men made him, he would be dead.
 
So it is a compromise. 55VAC effective is 95V peak. Completely illegal without RCD elsewhere in the first world. To me it looks like fixing one evil with another.

And yes, never pass underneath scaffolders at work unless you want to commit cuicide. Don't think I'm against hard hats where they make sense. I wouldn't go without on a site unless there is absolutely nothing above me.
Sorry for provoking a bit. I tried to find out how much people think that the comparably exaggerated UK HSE makes really sense. I met people who wouldn't visit the toilet without a proper risk assessment. Thanks anyway.
 
50VAC is defined as extra low voltage and safe to touch in this country. Whilst site supplies go an extra 5V above this to earth, I don't think it'll make a huge amount of difference.

It does not matter if the peak values exceed this.
 
Yes it matters. Actually it is the only value that matters regarding your heart.
We stopped using 48VAC as controls current some 30 years ago, because it became illegal. Nowadays it is 24VDC Europe or 12VDC US.

So I'd recommend a state of the art power supply at 230V single phase or 400V three phase.
 
OK then.

50VAC RMS is defined as extra low voltage and safe to touch in this country. Whilst site supplies go an extra 5V above this to earth, I don't think it'll make a huge amount of difference.

It does not matter if the peak values exceed this, as they have been taken in to account when deciding that ≤50VAC RMS is ELV.
 
The 50VAC maximum has to be insulated. Safe to touch is 25VAC.
Nice to hear that it is ok to push the limits (break the rules) if it is only by a bit.
So there is no consistancy. So I got a point to refuse the 110V annoyance and ask for a safe 230V supply which is fused at 16A and RCDed at 30mA. Thanks.
 
Not in our regulations. 50VAC RMS is the safe touch voltage.

110V CTE supply is over 50VAC, so it must be and is treated as any other LV supply.

Maybe that's why it's 55V and not 50V to earth. It's wired and treated as LV yet in reality, it's as safe as ELV. What a great system.


There is no way you can argue that 230V to earth is as safe as 55V to earth just because you have an RCD in the supply, bearing in mind that RCD's do NOT prevent you from getting an electric shock.
 

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