G9 capsule lamps: where they are used and how to switch to LED

G9 is a small two-pin capsule with looped pins. Where you find it, why it runs so hot, and what to check when replacing it with an LED version.

Look inside many modern chandeliers, small wall lights and designer fittings with glass shades and you will find a clear capsule about the size of a finger instead of a screw-in bulb. There is no thread at the bottom, just two looped wire pins. That is a G9 base, and when it burns out people often confuse it with a G4 or a small E14 bulb.

What a G9 looks like

The giveaway is the pins. Rather than straight prongs, they are loops of wire bent back on themselves, spaced about 9 mm apart, which is where the name comes from. The lamp is not twisted in; it pushes straight into the holder, and the loops are gripped by spring contacts inside.

The classic G9 is a halogen capsule: quartz glass with a tightly wound filament inside. It is easy to tell apart from a G4, which is smaller and has thin straight wire pins instead of loops.

Where it is used

G9 caught on wherever a small size had to deliver plenty of light:

• modern chandeliers with many small lamps and "rain" style pendants;
• wall lights with glass or metal shades;
• compact ceiling fittings and lights built into furniture;
• some cooker hoods and appliances.

The key point is that G9 normally runs on 220–240 V mains and needs no transformer. That sets it apart from the 12-volt G4.

The weak side of halogen G9

A halogen capsule produces a lot of heat in a very small volume. In an enclosed glass shade that heat builds up, and over time the holder contacts and the cable insulation harden and crack. Blackened holders and brittle wiring are a familiar sight in older G9 fittings.

It is also best not to handle halogen capsules with bare fingers. Skin oil left on the quartz creates a hot spot on the glass and can shorten the lamp's life, so use a cloth or a glove when you change one.

Choosing an LED G9

An LED G9 gives off far less heat for the same light, which is a real advantage in enclosed fittings. The switch still involves a few checks.

Size. Because it contains driver electronics, an LED G9 is usually longer and wider than a halogen capsule. In a narrow glass shade, or a fitting where the lamp sits inside a decorative frame, it may not fit. Measure the old lamp and compare it with the dimensions of the new one.

Light direction. Some cheaper LED G9s have diodes facing only one or two sides. In a clear chandelier with crystal drops this produces patchy light. Models with diodes arranged all round the body, or round silicone-coated types, spread the light more evenly.

Dimming. Halogen G9s dim happily on an ordinary dimmer. An LED G9 will only do so if the pack says "dimmable"; a non-dimmable LED on a dimmer circuit may flicker or buzz.

Voltage. 12 V G9 lamps do exist, though rarely. Make sure the pack states 220–240 V.

How to change one

• Switch the light off and, if it was halogen, let it cool.
• Pull the lamp straight down without twisting; if it is tight, rock it gently from side to side.
• Check that the holder is not blackened and the contacts have not gone loose. If you see scorching or melted plastic, replace the holder first.
• Push the new lamp straight in until the pins are fully seated.

When it makes sense to replace the fitting instead

Sometimes the problem is the fitting rather than the lamp. If a chandelier with dozens of G9 lamps already has several blackened holders, wiring that crumbles when touched and lamps that keep going out, swapping each one for an LED will not undo the old heat damage. In that case it is better either to have the chandelier rewired by an electrician or to replace it with a fitting that uses fewer holders and an ordinary screw cap.

Availability is worth considering too. Special lamps like G9 are less common than ordinary E14 and E27 bulbs, and the choice is narrower. Keeping that in mind when buying a new fitting saves time hunting for lamps in the years that follow.

When looking for a replacement for a special base like G9, checking size, light spread and voltage first saves the most time. The product filter in the Zaferoğlu Elektrik Zəfər İşığı catalogue shows which bases are currently offered.