LED lamp bases: types, marking, technical parameters + how to choose the right one

Vasily Borutsky
Checked by a specialist: Vasily Borutsky
Author: Lydia Korzheva
Last update: May 2019

A cap is that part of the lamp with which they are connected to the lampholder. Products provide a snug fit of the contacts through which the lamp receives power. All existing cartridges are divided into categories and can only work in tandem with a lamp having a suitable base.

Therefore, when choosing a lighting device, this parameter is primarily paid attention to. We offer to understand what are the bases of LED lamps, what are the specifics of using various devices, and how to choose the suitable option.

Types of lamp bases on LEDs

One of the criteria by which to distinguish LED lampis a view of the cap. All of them can be divided into two volume categories - threaded and contact. There are many species within groups, but among them there are five of the most popular.

E27. They are used for all standard luminaires, and for those where the luminous flux exceeds 1200 Lm, only this type is used. Usually, E27 lamps operate in alternating current and at a voltage of 220 V.

E14. Applicable to all variants of standard fixtures, but with miniature dimensions. Lamps with E14, which are also called "minion", have interesting shapes: candle, fungus, bulb.

GU10. Has a two-pin connector, swivel mount. They are used for ceiling lighting fixtures in the form of LED lamps with frame size MR16.

A light source placed in the cartridge holds a special lock, because of this they are in demand in places where vibration or other external influences are observed.

GU5 / 3. They are used in luminaires with LED lamps, reflex type MR16 for decorative lighting. They are powered by 220 and 12V.

G13. Used for tube-shaped lamps T-8 and T-10. They are installed in ceiling panels, which are most often found in office premises for targeted lighting of workplaces.

Types of caps
Before you purchase a new lamp for your lamp, you need to decide on the type of base used in it.There are many types of these elements and far from all of them are interchangeable (+)

The first two types are threaded. To connect the product with such a base and a cartridge, they screw it in, like a simple incandescent lamp.

The remaining three types are contact or pin. These socles are equipped with pins located on the edge of the lamp.

Less popular threaded sockets are E10, used in lamps that illuminate the interior of refrigerators and E42 for street lamps.

LED luminaires, widely used by designers, are equipped with transition elements G4, GU4, G9.

Features of threaded holders

Threaded products are the most purchased options for socles. They are equipped with floor lamps, table lamps, lamps, lanterns. In sconces, small-sized table lamps, pendant lights and chandeliers, they are more often used lamp E14.

LED lamps with such an adapter are gradually replacing incandescent lamps, "housekeepers", from household appliances.

Lamp with socket E27
A light source with a base E27 is a more advanced analogue of a 90 W incandescent lamp. With a power of 11 watts, it gives the same illumination as its more powerful prototype

For high power luminaires, the most suitable are socles E40. They are used in industrial plants, in street lighting.

There are also less popular types of threaded sockets:

  • E10, E12, E17 - small with diameters of 10, 12 and 17 mm, respectively;
  • E5 - microscopic with a diameter of 5 mm;
  • E26 - middle.

The threaded base is attached to the flask by means of adhesive bonding. If you need to replace the lamp, you need to do this carefully, otherwise the base may break off. In the case when this still happens, you need to disconnect the lighting device.

The next thing to do is to carefully unscrew the damaged base with pliers. And it is better to avoid such situations when replacing the lamp thread rubbing graphite.

Features GU10, GU5 / 3, G13 and G23

GU10. In LED lamps, the GU10 holder is arranged non-standard. At the ends of the contacts, it has extensions that firmly hold the lighting element in the cartridge.

Pin base
The base of this type is pin. Its contacts are located at a distance of 1 cm. The addition in the form of the letter U indicates the presence of structural features of the device (+)

The LED light source with this base, along with the same parameters as the halogen analogue, has several advantages.

She has more intense light, a significantly longer duration of operation, minimal power consumption. The main advantage is that it practically does not heat up.

Devices with a GU10 base are powered from a network of 110 - 220 V. Typically, lamps with such a holder are equipped with a reflector to give the light a certain direction.

A limited number of manufacturers produce low-voltage lighting elements. This is explained by the narrow scope of demand - a purely local lighting system.

Use their designers for interior lighting. They are ideal for spotlights.

GU5 / 3. The ceramic base of GU5 / 3 contains wires enclosed in a protective sheath. Imported products operate at a voltage of 12/24 V.

But in Russia, lamps with such a base are more common, adapted to the usual 220 V. They are connected to the network via terminal blocks, which is more reliable.

Base for spotlights
The G4 pin base is often present in small spotlights that have found application in decoration

LED lamp G4 often used to replace low-voltage halogen lamps in chandeliers.

Contacts are located at a distance of 5.33 mm from each other. Luminescent lamps in which GU5 / 3 are used represent an analog of halogen multifacet reflectors and are energy saving.

G13 and G23. They are installed not only in T8 LED lamps, but also in lighting devices such as Armstrong, LSP, and others. The distance between the contacts is 1.3 cm.

G23 are for “U” shaped lamps. A starter is included in its design. Start is carried out by means of a throttle, usually located in the lamp housing. The power of such devices is from 5 to 14 W, they are screwed mainly into table lamps.

Base bayonet mount

There are special pins on the body of this connecting device. With their help, the base is connected to the cartridge. When developing the product, a specific goal was set - to make the lighting device acquire more compact forms, and the time for replacing bulbs was reduced.

Round side pins (2 pcs.) Are located symmetrically on the base. They are fixed in the slots of the cartridge intended for this, and then rotated by орота turn for better fixation.

Bayonet socket lamp
Pictured is a LED bulb with a bayonet cap, marking - BA15D. lamp dimensions - 22 * ​​60 mm, voltage - 0.5-1 V

One type of pin product is the base VA with asymmetric side contacts. Apply it in cars. A peculiar design allows you to specifically insert the lamp into the cartridge and focus the luminous flux of the headlights.

In some countries, mainly English-speaking, pin connectors indicate BC, short for Bayonet Cap, in Europe - B22d, in Russia - 2Ш22.

The analogue of the European B15d is the domestic 2Sh15 and in English - SBC, the full name is Small Bayonet Cap. MBC / MBB corresponds to Russian 1SH9 and European Ba9s.

Rare holders

Some types of these integral elements of the lighting device are quite rare. These include recessed contact devices.

Characteristics of rare types of cap

With recessed contact. Belonging to this species indicates the presence in the marking of the symbol "R". Use them in lamps of small dimensions and light weight.

Soffit "S". There are location options both on one side of the tube lamp, and on two. Such socles are appropriate in fixtures used as a mirror illumination, in bathrooms, as well as in car dealerships.

Soffit Base
Socket spotlights with contacts spaced on opposite sides of the lamp. Once they were used only to illuminate the scene, whence comes the name

Locking "P". In film projectors, lanterns, searchlights use the base "R" - fixing. By design, it resembles a spotlight. The difference is in the presence of an additional scattering area.

The direction of the desired luminous flux sets the assembly lens. The design is used for film projectors, spotlights, flashlights.

Telephone "T". This type is used in lamps used as backlights, in remotes, dashboards in cars.

Telephone base
The T6.8 base is used in KM bulbs (commutator). The number after T indicates that the contact pins are spaced 6.8 mm apart

In the European Union, KM bulbs with smaller sizes are used. On the base they are marked 6 T4.5; T4.6; T5.5.

Glass and cable variations

Among a wide variety of LED lamps, there are those that are called baseless. This element is there, but it is glass, like the lighting device itself.

Lamp with a glass base
Their use is narrow-profile. They are found most often in the automotive industry. When the “W” symbol is at the beginning of the marking, it means it is a lamp with a glass base

On its basis there are current conclusions. Through them, the glass cap contacts the cartridge. The numbers in the marking indicate the thickness of the glass portion. They are followed by an “x” and the width of the base.

Cable socles (K) are not so common. The scope of their application is projector lamps.

How to decipher the marking?

The designation of these products includes several characters in the form of letters and numbers. The latter speak of the distance between the contacts or the diameter of the connecting part.

Symbols indicating the belonging of the socle to a certain type are deciphered as follows:

  • "E" - the base of Edison, i.e. threaded;
  • "G" - pin;
  • "R" - equipped with a recessed contact;
  • "R" - focusing base, allowing you to position the lamp in the desired position;
  • "AT" - bayonet mount or pin;
  • "F" - has one pin;
  • and - the pin has the shape of a cylinder;
  • b - equipped with a corrugated contact;
  • with - indicates the original shape of the pin;
  • "S" - spotlight.

The number of contacts indicates a specific symbol: one contact is s (single), d is a pair (duo), t (tres), q (quatro), p (penta) are three, four and five contacts at the end, respectively.

Refinements are denoted by the letters U, V, A. The first is labeled with energy-saving lamps, the second is a device having a conical end, the third is automobile lamps.

Base designation scheme
When designating a cap, use the A00bC scheme, where the first character (A) is the type of cap, the second is its size, b is the number of contacts, C is additional data. The last marker may not be (+)

Pin models with the symbol “X” are present in spotlights. Since the flow has a clear direction, they help to set the right accents in the room. In special-use lamps, the “Y” and “Z” models are used.

Lamp with connector E27
LED lamp with E27 connector. It is used without additional devices on the 220 V network. It does not work with electronic dimmers

The inscription E14U indicates that the screw cap has a diameter of 14 mm. The lamp itself is energy-saving. The BA9 marking indicates a diameter of 9 mm, round pins placed symmetrically.

How to choose the right base?

By this criterion, the choice is quite simple: you need to take into account the parameters of the lamp available.

Manufacturers produce many LED lighting devices. They can replace both incandescent and halogen lamps.

Furniture lighting
For the first group, the socles E14, E27, E40 are interchangeable. For the second - GU10, G4, GU5.3. In recessed lamps used to illuminate furniture, use the base GX53

When choosing, you should know some nuances:

  1. Models with G9 holders are designed for 220 V.
  2. If the circuit contains electronic switches and dimmers, you can not use small lamps with E14 and E27 socles.
  3. Since there are many options for lighting fixtures with pin connectors, you can easily make a mistake when choosing. For this reason, you do not need to get rid of a burned out lamp.

Manufacturers adapted almost all types of socles to LED light sources. In order for the device to work stably and for a long time, it is necessary to take into account the permissible power for a certain lamp.

So, if the limit on this parameter is 40 W, then you can not install a lamp on LEDs, designed for 6 watts.

Read about additional options for choosing LED lights in this article.

Conclusions and useful video on the topic

Overview of the main types of cap:

Features of the choice on the example of Philips LED lamps:

When buying LED lamps, you must first look at the base. Its geometry must match the configuration of the cartridge. When lighting fixtures are needed for powerful equipment, the technical documentation should serve as a guideline.

Looking for LED lights for your home or apartment? Or is there experience in the selection and successful use of such lamps? Please leave comments on the article, ask questions and participate in discussions. The contact form is located below.

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Visitors Comments
  1. Daniel

    At my place there are only 14 and 27 socles. Especially never bothered with a variety. As for me, this is enough. They are the most common.