6 W R7S LED bulb, 78 mm R7S LED
An example of the short R7S format, 6 W and 78 mm.
Check the model's overall length, diameter, voltage and dimming capability before ordering the replacement.
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78 or 118 mm R7S LED: how to check a replacement fits
To choose a 78 or 118 mm R7S LED bulb, start with the replacement's length and the space inside the light fitting. Then check the power supply and the dimmer, if fitted. Two bulbs can share an R7S connection but have different bodies: matching end contacts do not guarantee that the new bulb will fit beside the reflector or allow the cover to close.
This guide helps you prepare to buy a replacement for an existing floor lamp, wall light or floodlight, bringing together the details you should have before ordering.
78 and 118 mm: two lengths you need to distinguish
The 78 and 118 mm designations identify common lengths for these linear bulbs. Choose the one that matches your fitting, without moving the contacts to accommodate a different size. Check the replacement's overall length on the drawing, including its ends, and compare it with the model of the bulb you removed.
Technical documentation lists these measurements separately: the LEDVANCE LED Line 78 data sheet gives length and diameter in separate fields. This is an example of how to read a drawing; those dimensions apply only to that model.
A measurement sheet to use when shopping
Copy these details from the drawing and the markings. The nominal lengths of 78 mm and 118 mm are equivalent to 7.8 cm and 11.8 cm; they are not interchangeable.
- Model of the light fitting and the bulb removed: __________
- Overall replacement length, including ends: __________ mm
- Maximum body diameter and shape: __________ mm
- Available clearance to the reflector, sides and cover: __________
- Rated voltage and any auxiliary equipment: __________
- Dimmer make and model, if fitted: __________
- Use in enclosed fittings permitted by the manufacturer: __________
Do not record an estimate as though it were a confirmed measurement. If you cannot safely access the markings, give a professional the photographs you have.
Measure the body and the available space, as well as the length
With the fitting disconnected from the power supply and the bulb cool, take photographs of the markings and the housing. If access involves disconnecting wiring or working at height, have a professional carry out the inspection. Do not measure or handle live contacts.
Three areas to check
- Behind the bulb: check the available clearance to the reflector and any projections.
- The sides: identify screws, brackets and narrow areas that could obstruct the replacement's body.
- The cover: check that it can remain in its intended position without touching the bulb or altering the closing mechanism.
The space needed to insert and remove the bulb also matters. A body may fit on paper yet be impossible to manoeuvre into position. The LEDVANCE LED Slim Line 118 data sheet illustrates why compact versions specify their own diameter. The word ‘slim’ is no substitute for checking the drawing.
Check the power supply, dimming and conditions of use
Copy the voltage marked on the fitting and compare it with the replacement's voltage. If there is auxiliary equipment or you cannot identify the power supply, seek advice before buying. The R7S designation alone does not establish compatibility with the complete fitting.
For a floor lamp with a dimmer control, look for an explicit statement that the bulb is dimmable and compatible with that control. LEDVANCE refers to specific dimmer checks for its dimmable R7S range. The fact that the previous halogen bulb was dimmable does not confirm that its LED replacement is.
Also check temperature requirements and suitability for enclosed fittings. Keep all the protective parts required by the fitting; if the replacement requires you to remove a necessary cover, find another compatible solution. Do not improvise modifications to make it fit.
Practical example: replacing a floor lamp bulb
Imagine a lamp with a 118 mm linear bulb and an in-line dimmer. The first check rules out 78 mm replacements. The second is to check the diameter and the space beneath the cover. The third requires you to identify the dimmer and find a compatible replacement.
If the drawing or dimming statement is missing, the next step is to send the model details and photographs to get clarification. Buying first and bending the reflector afterwards is not a compatibility test. If the fitting is damaged or no suitable replacement is available, it is also worth comparing the cost of replacing the fitting.
Two LedsCome products to start your comparison
The 6 W, 78 mm R7S LED bulb is a starting point when looking for the shorter format. The 12 W, 118 mm R7S LED bulb is the longer format stated in its description. For both, confirm the diameter, voltage, dimming capability and permitted use in your fitting.
The 6 and 12 W figures indicate power consumption, not the wattage of the halogen bulb they can replace. To compare the light output, you need the declared luminous flux of both the replacement and the removed bulb, as well as an assessment of their light distribution in the reflector. Without that information, there is insufficient evidence to confirm an equivalent light output.
12 W R7S LED bulbs
An example of the long R7S format, 12 W and 118 mm according to the description.
Confirm the diameter, voltage, dimming capability and conditions of use; do not infer equivalent light output from wattage.
View details and optionsChecklist before ordering
- The previous bulb's model details and a legible photograph.
- The replacement's overall length and body dimensions.
- Clearance beside the reflector, brackets and cover.
- The fitting's voltage and dimmer compatibility, if applicable.
- Conditions of use and documentation for the exact model.
- The desired luminous flux and light colour.
Frequently asked questions about R7S LED bulbs
Can I remove the glass if the new bulb touches it?
Do not remove it as an improvised fix. Check the fitting's instructions and find a replacement compatible with its protective parts.
What should I do if the old model number is illegible?
Photograph the fitting, its label and the housing with the power disconnected. These pictures and measurements will make it easier to identify suitable options.
If you are considering replacing the fitting, see the differences between integrated LEDs and replaceable bulbs. To compare light distribution, see the guide to beam angle. You will find more help in the lighting guides index.