Lamp holder: device principle, types and connection rules

You have to replace the cartridge for the bulb with a new one, but you don’t know how to do it correctly, so as not to damage the important wires and nodes? For such a simple job you do not want to call an electrician, whose services will be quite expensive, right? Or do you need to upgrade your home electrical network with the replacement of individual elements?

We will help to deal with the peculiarities of connecting various cartridges - the article discusses the main varieties and marking of factory electric cartridges.

Also provides instructions for connecting the cartridge with screw terminals and consider the existing options for mounting it in lighting installations. Pictorial photos with step-by-step process of connection and installation, and videos showing the replacement of the cartridge, the correct connection of wires to it were selected.

Purpose and features of the cartridge

A production or home electrical network consists not only of wires and fixtures, but also of many electrical installations that serve to control or connect individual parts of the circuit.

The cartridge connects the base of the lamp with electrical cable and simultaneously fixes it in the lamp, chandelier, or simply holds it in suspension.

The problem of fast lamp replacement arose immediately, as electric lighting was invented, that is, at the end of the 19th century. The first lamps had caps, but the methods of connecting them to the wires were different and had no classification.

In 1881, Edison patented the first screw-type base and cartridge for it. Thus, the most popular types of socles and cartridges remain relevant for over 130 years.

Of course, incandescent bulbs were originally invented. Then gas-discharge and light-emitting diode LEDs appeared, for their installation both usual and structurally different types of cartridges were required.

Filament lamp holder
Same sizes make it easy to replace: instead of an incandescent lamp, a more economical alternative can be screwed into the same cartridge - a LED with a screw base or a filament “pear”

For the manufacture of modern cartridges using various materials, among which you can find the traditional metal and ceramics, as well as heat-resistant polymers and even silicone.

The latter option is most often used to create design compositions. Silicone products are equipped with 1 m electrical cord and painted in all colors of the rainbow.

Image Gallery
Photos of
Heat-resistant plastic for low-power lamps
Heat-resistant plastic for low-power lamps
Ceramic products with metal liners
Ceramic products with metal liners
Metal cartridges with a dusting
Metal cartridges with a dusting
Decorative silicone products of different colors
Decorative silicone products of different colors

When buying a sconce, chandelier or other fixture, you should carefully consider the manufacturer's recommendations: if you install too powerful lamps, cartridges can fail, and the ceiling lamps can be deformed.

Types of electric cartridges of the type of cap

As already mentioned above, two large categories of cartridges remain in demand - under the threaded base and under the pins. They are often universal, that is suitable for different types of lamps.

For example, incandescent lamps and LED devices stylized for them are equipped with threaded lamps.

But some products can only interact with one option. Let us consider in more detail their design features and technical characteristics, on which you need to rely when choosing.

№1 - popular threaded options

Cartridges with internal thread are designed for lamps with a threaded base. Dimensions are usually denoted the same: for example, for a lamp with an E14 base, an appropriate E14 cartridge is required, although a variant with an adapter from E27 to E14 is possible.

The numbers 14 and 27 designate the diameter, while 27 is often considered as the classic size, and 14 is called the minion.

LED lamp with a rezbovy socle
LEDs have come to replace incandescent bulbs: in stores you can encounter a large assortment of LED bulbs for E14 and E27 threaded chucks from various manufacturers

A total of 8 sizes of bases, therefore, the same number of rounds for them: E5, E10, E12, E14, E17, E26, E27, E40.

Diagram of a threaded plastic cartridge
Diagram of a threaded plastic cartridge. The "phase" and "zero" conductors are inserted into the cartridge through the upper hole and fixed inside the case with screws. If there is a "earth", then it is fed to the metal parts of the lamp.

The most popular are plastic products.They have a limited service life and are subject to the requirements set out in GOST 2746.1-88. The method of mounting the cartridge may be different and be suspended, with a straight or inclined flange.

The first is used for mounting to the ceiling or mounting fixtures, and flange - for installation on the surface.

Lamp with flange chuck
A popular example of a lamp with a flange chuck is a table lamp-night light. The type of flange is straight, therefore, the light bulb is positioned strictly vertically

Table of the characteristics of the most common threaded sockets for connecting lamps to the electrical network, which differ in size. The larger the diameter of the cartridge, the higher the power and load current.

Cartridge size Maximum power, W Load current, A Purpose
E14 440 2 Cartridge with internal thread ∅14 mm, which is also called the "minion". Apply to incandescent household type with low power
E27 880 4 Cartridge with internal thread ∅27 mm, which is considered traditional, but is increasingly replaced by 14 mm. Used for various types of medium power lamps
E40 3500 16 Ceramic cartridge with internal thread ∅40 mm. It is used to connect high-power lamps required for street or industrial lighting.

The body is made of various types of plastic, so before using the lamp it is necessary to study the marking - find out the allowable power of the lighting device.

If you screw in a high-power bulb, the plastic will melt or gradually break from regular heating.

No. 2 - variety of pin varieties

Requirements and standards relating to pin cartridges are placed in GOST R 60400-99. They function from the 220 V network. The letter G indicates the type of cartridge (pin), and the next number is the distance between the two holes for the pins.

If the contacts are not 2, but 4, then the diagonal distance between the opposite holes (grooves) is indicated. Special types are marked with additional Latin letters or numbers.

Installation of a spotlight
Cartridges labeled “G” are used, among other things, for the installation of spotlights in suspended structures. For this purpose, in stretch ceilings, mortgages to the concrete base are mounted.

Cartridges for pins are used for domestic and industrial premises, as well as for lamps that are installed on the street - along the park paths, the roadway, to illuminate playgrounds or the local area.

Cartridge size Maximum power, W Load current, A Purpose
G4-G10 60 5 Versions from G4 to G10 inclusive are suitable for mounting low-power halogen lamps. The number after “G” is the distance in millimeters between the pins
G9 60 5 Lamps for G9 holders have a loop-shaped flat base, which is inserted into special grooves
GU10 50 5 Analogue of the cartridge for the base G10. The bulbs at the ends of the pins have bulges that are inserted into the holes and then fixed with a pivoting motion
G13 80 4 Cartridge for linear lamps for various purposes. Features - double use and swivel connection mechanism
GX53 50 5 Analog G10, but with an increased distance between the pins - 53 mm. Designed for installation in suspended structures, therefore, has a minimum thickness.

For installation of U-shaped and cylindrical lamps use cartridges GX23, G24, 2G7. They differ in the number of contacts - 2 or 4, have a load current of 2A. The recommended lamp power is up to 75 W (for 2G7 - 50 W).

Schematic images of socles and cartridges
Schematic images of the base and socket of some types of pin and pin lamps. Usually, no pin adapters are used for the pin connection, as is possible with threaded counterparts E14-E27

Thus, pin cartridges can differ in the following characteristics:

  • case material;
  • inner liner material;
  • type of attachment of the cartridge to the base and wires;
  • number of contacts;
  • the distance between the pins.

All listed parameters can be specified when marking the product.

Linear elongated discharge lamps have a slightly different type of mounting. In addition to the fact that the cartridges are paired (the lamp is inserted from both sides), they are designed to operate on 220 V and 380 V mains, with a rated current equal to 1 A or 2 A.

By design, the cartridges are end, overhead and rack-mount - this also depends on the type of lamps used. The number of contacts can be different: for example, in the presence of a conductive strip - three instead of the usual two.

Fluorescent lamp with cartridge
Over time, the cartridges wear out. This can happen for completely different reasons: due to a crack in the case, electrical contacts or a mechanical damage during operation.

In order for the cartridge to work out the warranty period, it is necessary to follow the installation rules, select the product according to the lamp specifications, select the desired type of protection (waterproof or dustproof).

In addition to cartridges for pin and threaded bases, there are products for other types: focusing, pin, with recessed contact, soffit.

They are used to install and connect LED and gas discharge lighting devices.

Factory marking

Professional electricians are not content with the same size and quick visual inspection of the product, they carefully read the markings printed in ink or stamped on the visible part of the cartridge.

Metal cartridge marking
Typically, the label indicates technical characteristics or conditions of use, which are of fundamental importance when choosing light sources

The most responsible manufacturers and labeling put, and attach to the product brief guidelines listing important characteristics.

The list of parameters that can be found on the cartridge is not always complete. Usually reflected any of the listed characteristics:

  • type (for example, threaded, pin);
  • the size;
  • temperature;
  • load current;
  • power;
  • voltage;
  • trademark manufacturer;
  • level of protection;
  • grounding contact

Before purchasing cartridges, check the manufacturer’s website, which usually contains detailed technical information and a diagram with dimensions.

Details of the cartridge
In addition to reviewing the technical characteristics and conditions of use of the product, it is necessary to clarify exactly how the cartridge is mounted and what holes / latches are provided for fixing

When choosing, it is also worth considering that ceramics is stronger than plastic and can withstand higher temperatures. If the cost of the product is doubtfully low, it is likely that it is a fake.

It is better to insure yourself and buy a more expensive, but high-quality electric cartridge of a reputable brand.

How to connect the cartridge?

From household products, it is most difficult to connect the wires to the old type of cartridge - the “Soviet” one, since it must first be disassembled.

These devices are easily recognizable by the black polymer case. To get to the terminals, the carbolite case must be unscrewed.

Disassembly of the cartridge for connection
Disassembly is performed by rotating the housing parts in opposite directions. As a result, the cartridge is divided into 3 parts: the holder (the largest element), the back part and the central part - contact ceramic insert

In order to fix the wires, they need to be stripped and arranged with “eyelets” in order to make it easier to fix them on the contacts.The phase is fixed to the central screw-contact, zero - to the second terminal.

When tightening the threaded connection, it is necessary to apply force and remember that it simultaneously transfers voltage to the contact. When the wires are connected, it remains to connect the two parts of the case.

Fastening methods in lighting

The difficulty of installing the cartridge may be caused by the design of the chandelier or lamp. In order to quickly cope with the replacement of a broken product, we recommend in advance, before the initial installation of the lighting device, to get acquainted with its device and position.

Manufacturers of luminaires most often choose the following methods of fastening cartridges:

  • for electrical wire;
  • on a metal tube;
  • using a sleeve;
  • snaps.

In the first case, it is necessary to further strengthen the wire, for this purpose, use a sleeve with a fastening screw, which is screwed into the bottom of the cartridge.

The metal tube is used more often, as it allows you to install heavy chandeliers with a large number of decorative elements.

Chain chandelier
Often, instead of a tube, a metal chain is used, which also reduces the load on the electrical wire and allows you to adjust the height of the hanging fixture

Cartridges with bushings are exposed to heat, as a result of which the elements are deformed. Therefore, plastic bushings are recommended to be replaced with metal ones.

The last mounting option is suitable for devices with screwless terminals. The cartridge is installed in parts. First, fix the bottom, then insert the wires, and only then mount the remaining part of the cartridge with the help of latches.

Connection option with screw terminals

More modern cartridges do not need to disassemble - the terminals are located on the outside. Wires are fixed with screw clips, the connection process takes only a few minutes.

The only disadvantage of such a cartridge is the impossibility of repair. If the terminals are burned or the product is deformed, you will have to change it completely.

Image Gallery
Photos of
Step 1 - Stripping the ends of the wires
Step 1 - Stripping the ends of the wires
Step 2 - Unscrew the mounting bolts
Step 2 - Unscrew the mounting bolts
Step 3 - Phase Detection and Terminal Selection
Step 3 - Phase Detection and Terminal Selection
Step 4 - Connect Wires to Terminals
Step 4 - Connect Wires to Terminals

The connection option with clips is relevant for luminaires designed for E14 and E27 lamps. When installing a new cartridge and replacing be sure to check it for integrity and compliance with the standards.

Suppose that the number of turns should be at least three, and there should be no cracks and chips on the case.

Conclusions and useful video on the topic

Installation of various lighting devices may differ, therefore we present several video instructions for connecting.

Connection of ceramic and carbolite cartridge:

Option of attaching wires to the plastic cartridge:

G4 cartridge replacement:

Cartridges are arranged quite simply, so disassembling, replacing or repairing home electrical installations can be done by hand.. The most important thing is to turn off the mains voltage, if you work with a lighting device, and strictly follow the recommendations of experienced electricians. When installing a new model should be based on the instructions.

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