>When was the ES27(?) lampholder introduced
>to your country?.
When bulbs were introduced. Guess why it is called Edison?
>What types of fittings are they predominantly used in?.(Currently)
All large fittings that take bulbs. (Including mercury lamps) The smaller ES14 is also popular. (In a few cases bayonet cap sockets are used as they're non standard, preventing theft.)
Only fittings intended for low-energy lamps of various types use special holders. These lamps are often horribly expensive.
>What is the maximum wattage of lamp, allowed
>in your fittings using these lampholders?.
Plastic: 60W
>Are there Regulations to require that the
>Phase wire, goes to the centre terminal of
>the l/holder?.
No. For wall mounted switches, you are required to switch the phase wire, not the neutral. (You may of course switch both if you want to.)
[This message has been edited by C-H (edited 11-26-2002).]