T8 LED TUBE 18W 1200mm
18 W, 1200 mm T8 tube. Confirm compatibility with the gear and power supply arrangement before ordering.
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What to check before replacing a fluorescent tube with LED
Before replacing a fluorescent tube with LED, check three things: dimensions and connections, the equipment powering the fitting and the condition of the assembly. A new tube of the same length is not enough. Gathering model references and photographs before buying lets you ask about specific compatibility and avoid orders based on appearance alone.
Which details you need from the tube and fitting
Note the old tube's complete reference, format, length and cap. Add the make and model of the fitting, how many tubes it uses and whether it has dimming, sensors or an emergency function. Keep an overall photograph and another of any markings you can read without accessing electrical parts.
The detail often missing is the reference of the ballast or power supply. If the fitting needs opening to see it, have a professional identify it. An incomplete label or a previous repair may leave questions that the tube length cannot resolve.
| Detail | What it helps with | What it does not prove |
|---|---|---|
| Format, cap and length | Checking the intended fit | Electrical compatibility |
| Power supply model | Checking the permitted combination | That any LED tube will work |
| Number of tubes per unit | Identifying the complete configuration | That a test with another configuration is valid |
| Dimming, sensors or emergency operation | Requesting a specific check | That those functions will be retained automatically |
How to check electrical compatibility
Tubes are available for different power supply arrangements. The LEDVANCE technical FAQs distinguish conventional and electronic gear and ask for the latter to be checked against the relevant list. That documentation explains the checking method; it does not by itself approve products from other brands.
Find the exact code of the candidate tube and the exact ballast reference. Then check the permitted number of lamps and the notes for that combination. The Signify professional list, Q3 2026 edition, separates those details and includes notes on dimming and variations in luminous flux.
If information is missing, leave the purchase pending confirmation. Do not extrapolate a result between similar models or treat initial operation as sufficient proof. Modifications to a fitting require professional assessment and specific instructions; this guide does not provide wiring diagrams.
Also review the condition and the light you need
A fitting with a damaged diffuser, broken catches or repeated faults deserves inspection before reuse. The Signify assessment checklist covers the environment, fixings, lampholders and wiring condition. Internal checks are the installer's responsibility.
Describe what you want to improve: seeing warehouse labels more clearly, keeping a consistent light colour or reducing work in a hard-to-access area. Compare luminous flux, colour temperature and light distribution using each candidate's documentation. To assess object colours, see the guide to CRI.
Example: updating eight warehouse light fittings
Imagine eight fittings with two tubes each. The initial count is sixteen tubes, but that does not yet confirm what to buy. When checking references, the installer finds six fittings with one type of gear and two repaired with another. It makes sense to organise the enquiry into two groups and obtain an answer for each configuration.
Prepare a simple table with location, fitting, gear, tubes per fitting and notes. Once the solution is confirmed, agree on a representative test and assess the result before extending it to the rest. Keep the reference of the final installed product alongside its location: this will simplify later maintenance and avoid starting the identification process again.
Checklist before ordering
- Old tube reference and dimensions identified.
- Gear model and number of lamps confirmed.
- Documented compatibility for the chosen LED reference.
- Dimming, sensors and emergency functions communicated to the professional.
- Fitting condition and location conditions reviewed.
- Colour variant and number of units in each pack checked.
Two catalogue options to consider
The T8 LED TUBE 18W 1200mm provides a starting point for enquiries about a replacement in that format. Its available information does not confirm the permitted ballast or electrical input arrangement. The 120cm Sirio LED 36W Linear Light Bar is an alternative to consider for replacing the whole assembly, rather than a replacement tube.
120cm LED Linear Light Bar, Sirio LED 36W
36 W, 120 cm Sirio LED Linear Light Bar to consider for replacing the whole assembly; it is not a replacement tube.
View product details and optionsExplore the available LED tubes and compare maintenance with the guide to integrated LEDs or replaceable light sources.
Frequently asked questions about replacing fluorescent tubes with LED
Will a tube of the same length fit and work?
Length only addresses part of the selection. Also check the format, cap, power supply and fitting conditions before considering the replacement valid.
How do I know whether I can keep the ballast?
You need the ballast and LED tube references. The manufacturer's documentation must permit that combination and configuration; without it, request technical confirmation.
Are all LED tubes powered in the same way?
No. There are different arrangements. Do not infer the power supply from the cap's appearance or copy a previous installation. Follow the documentation for the specific model.
When is it worth replacing the whole fitting?
When its condition, maintenance or lighting result makes that worth considering. Compare both options with an assessment of the assembly and a quotation detailing which components will be retained.
What should I send when asking for advice?
The tube reference, measurements, legible photographs, gear model, number of tubes per fitting and special functions. If any detail requires opening the fitting, have the professional obtain it.
Continue with the guide to energy labels and EPREL or return to the lighting guide index.