Lamp Holders

Lamp Holders Points : Lamp Holders, Bayonet type, Edison screw type, Definition The connection to the lamps of au electric wiring, the wires or circuit cables is made with a lamp holder. There are two types of lamp holders.
(i) Bayonet type.
(ii) Edison screw type. (i) Bayonet Type Bayonet type normally used for lamps, whose wattage does not exceed from l5owatts or 200w. The lamp holders are designed for quick replacement of the lamp and they must hold the lamp. Without overheating, in bayonet cap holder a efficient grip is necessary when the lamp is t be suspended froñi flexible cord the type of bayonet types lamp hk1ers are as follows
(a) Pendent holder.
(b) Batten lamp holder.
(c) Switch holder.
(d) Bracket holder.

These holders are made by Bakelite, porcelain and brass. Pendent lamp holders are fitted with a cord grip. Batten holder is used directly with ceiling walls and on tables. Batten holders are used either for concealed and surface wiring. The switch type lamp holder consists of switch. When switch is operated with a push bar the lamp is (ON) and when again press the button the switch is (OFF). (ii) Edison Screw Type Edison screw type lamp holder consists of brass cap, porcelain base, phosphor-bronze screw connections, brass outer cover and porcelain insulating ring. E.S lamp holder is used for 200w lamps and above. This make a rigid connection with the lamp and suitable for heavy current lamps. It is frequently used for those places where vibration or rough handling is so much. The outer screwed contact of E.S lamp holder always connected to live wire of the supply and neutral to the threaded section. The coarse thread is provided on lamp cap which is screwed into lamp holder.