V.O.E.L.C.B.

Sparkingchip:

In that second document I linked to there is a good diagram comparing methods of earthing, the Australians used two earth rods with a VOELCB as in the diagram I posted earlier, being the Home Office recommended method.

Indeed the diagrams are very interesting. I will study them more thoroughly when I have had my afternoon nap and am fresher. Australian r'e on the right must have a bridge over the N conductor. I could not quite make it out, and initially thought that it must be a joint to N. Do you have a clearer image please? I think that re electrode on the left is the consumer's earthing electrode, and r'e is the V.O.E.L.C.B.s earth electrode that we called the "E" terminal of the device. Both electrodes must be isolated from the N terminal. The right hand r'e electrode must be positioned out of the resistance area of the left hand electrode.


When I was a child in the 50s, after I had had a bath I would sit on a towel placed on a hot tank in the bathroom. The prefab was very basic in design. The hot water tank was a cuboid shape and was galvanised steel. The tank contained an electric immersion heater. The electrical supply was via overheads to the bungalow. The earthing must have been via the underground metal water pipes. I do not ever remember inspecting the electrical fuse box. I was wondering just what would have occurred if the immersion heater had developed an earth fault due to a split element sheath. Presumably the loft header tank was metal, all pipes were metal, the bath was metal, the taps and internal pipes were metal, so effectively bonding was automatically present of all metal water pipes and connected stuff. So if the earthing was not 100 per cent perfect and the pipework rose in Voltage above true Earth, all metalwork would be at the same potential so no shock would occur to me in the bathroom.


Z.



 

Sparkingchip:

In that second document I linked to there is a good diagram comparing methods of earthing, the Australians used two earth rods with a VOELCB as in the diagram I posted earlier, being the Home Office recommended method.

Indeed the diagrams are very interesting. I will study them more thoroughly when I have had my afternoon nap and am fresher. Australian r'e on the right must have a bridge over the N conductor. I could not quite make it out, and initially thought that it must be a joint to N. Do you have a clearer image please? I think that re electrode on the left is the consumer's earthing electrode, and r'e is the V.O.E.L.C.B.s earth electrode that we called the "E" terminal of the device. Both electrodes must be isolated from the N terminal. The right hand r'e electrode must be positioned out of the resistance area of the left hand electrode.


When I was a child in the 50s, after I had had a bath I would sit on a towel placed on a hot tank in the bathroom. The prefab was very basic in design. The hot water tank was a cuboid shape and was galvanised steel. The tank contained an electric immersion heater. The electrical supply was via overheads to the bungalow. The earthing must have been via the underground metal water pipes. I do not ever remember inspecting the electrical fuse box. I was wondering just what would have occurred if the immersion heater had developed an earth fault due to a split element sheath. Presumably the loft header tank was metal, all pipes were metal, the bath was metal, the taps and internal pipes were metal, so effectively bonding was automatically present of all metal water pipes and connected stuff. So if the earthing was not 100 per cent perfect and the pipework rose in Voltage above true Earth, all metalwork would be at the same potential so no shock would occur to me in the bathroom.


Z.