Can I add my experience.
The firm I used to work for has thousands of metal cabinets in the street which are connected to single phase mains power cables using TN-C-S
Inside these metal cabinets there is a class C circuit breaker but no RCD.
With TN-C-S it is absolutely vital that correct polarity is observed.
Thank you Harrow.
The problem with electricity is you cannot see it, or smell it.
Sadly your first contact with it could be your last.
I have erred in installing systems, we all have.
I remember well as an apprentice wiring a spur unit accidentally shorting the earth and positive with a non insulated screwdriver. I was to stupid or lazy to go back for an insulated driver. Well in less than a second I heard a loud bang, smelt burning and all that was left was the timber handle of the driver.
When connecting systems to the mains I always checked the earth. On a large bungalow when I did so there was no earth connection. The bungalow was 15 years old and the earth conductor had never been connected to the consumer unit.
This meant that for 15 years nothing in this bungalow had been earthed. Now if anything in this bungalow had further been compromised by being wired with reverse polarity, someone could have been killed.
The problem with reverse polarity is your equipment will function perfectly until something goes wrong. It’s then that you are depending on the wiring to have been done properly for your safety. If it has not it could kill you, make no bones about it, it’s that serious. We use 230v in this country to reduce resistance and enable us to use smaller cabling. But with higher voltage comes greater risk, and requires better safety. The article I posted on my previous post is US based. They use 110v, and they state it probably won’t kill you, that does not apply here.
