A'van Electrics Praise for Jeff

II had a big deep and meaningful afternoon with an electrician friend of mine over a few beers about ELCB's.

I am completely wrong, I will try and explain.

From a house point of view,

The old system was what they used to call a MEN system main earth neutral, this has been replaced [up to a point] by the ELCB which only deals with the active and neutral. Some appliances mainly, fridges, electric stoves, air conditioners, and electric hot water systems are not connected through a ELCB so they are connected through an earth bus bar to earth. Most other circuits covered by the ELCB the neutrals all go to a neutral bus bar. All the earth wires are wired up except they are not connected to the earth bus at the meter board just hang there because:-

If you touch an active or neutral wire with one hand and a metal plumbing pipe with the other then the ELCB detects a CURRENT IMBALANCE between the active and neutral circuits and switches off within 30 milliseconds, if an appliance becomes faulty the ELCB again detects a CURRENT IMBALANCE between the active and neutral circuits and again switches off within 30 milliseconds, the ELCB will not reset until the faulty appliance is unplugged or you let the active or neutral wire go. The house ELCB is double pole in that when it trips it cuts both the active and neutral circuits.

The big question I hear you ask is, the earth and neutral circuits are both zero volts so why not join them together, well they both are not zero, one maybe but the other maybe up to 6 volts and you would finish up with nuisance tripping the BIG POINT is that the current between the active and neutral is in balance so with ANY imbalance the ELCB will trip.

This will explain why your earth wire was hanging loose it is not connected and does nothing as you are protected by your ELCB.

Some places around the world do connect the earth and neutral bus bars but they use a slightly different ELCB than we use in OZ.

Phew I think I've got that right. [I have only been talking about a single phase system here for simplicity]

One further point, as my friend pointed out with houses, in the same street you may have houses built from 100 years ago to last week and their electrical systems will vary immensely in capacity, wiring, etc BUT at the time they were built or since upgraded they were wired to the standards and safety practices at that time, and no authority would suggest that every house had to be brought up to the standards of the house built last week, who would pay for the upgrade, the original builder, the original owner, the present owner, the authority or anyone in between?

This brings me to the vans, electrically my van is safe both then [when built] and now, as it was built to the standards at the time, I have an ELCB on my double power/point but I do not have an overload C/B or master switch, but I can pull the plug out of the park pole or switch it off at the park pole and with overload I am protected by the park overload C/B.

The vans were upgraded with a single pole ELCB with master s/w and overload C/B [the single pole means the active circuit only is cut]. As you may be using a faulty extension lead with the active neutral wires crossed the vans had a second single pole ELCB added this time on the neutral circuit, not really necessary, but the heart is in the right place. Now I understand the vans are only going to have ONE single pole ELCB or ONE double pole ELCB [double here meaning cuts both the active and neutral circuits]

I have only been concerned because old vans going in for work, would have their electrics upgraded without being told or charged as if something was wrong and maybe all old vans SHOULD be upgraded, but this is wrong these vans were upgraded as a free service for customers they were perfectly safe, something for nothing, WOW.

Jeff, this is very good customer service, let everyone know. As my van is safe if I wanted to upgrade it I would expect to pay for it, and you have been doing it as a free service for customers out of the goodness of your heart, thank you.

(name withheld at writer's request)