Led Tubes are in my opinion a better replacement than fittings with LED's built in as it offers the flexibility of changing colours, easy re-lamps etc. Fittings with built in are largely disposable, which means we will have transitioned from a disposal lamp model to a disposable fittings model.These lamps come in two flavours, HF which are designed to operate with the original high frequency ballast in place, this is convenient but wasteful of energy as you are still powering the ballast. Secondly Switch Start / Mains, these will operate in switch start fittings and only require the replacement of the starter with an LED starter or better still will operate on 240V mains without the need for any control gear. This gives the best reliability and energy reduction.
In order to change from traditional fluorescent tubes you have to decide if you are going to modify the fitting to operate directly from 240V mains and this is the best approach. By removing the control gear you remove from the circuit a source of failure and save all the energy wasted in the control gear.
There are two type of control gear there is traditional magnetic gear with a starter unit also know as "switch start" and then there is electronic control gear know has high frequency ballasts. If you have decided to replace the lamps without modifyiung the fittings then you have to establish wich system your fitting is using.
Switch Start gear: If you are using switch gear then it is really simple you simply buy the correct type of LED tube and replace the trasitional starter with an LED starter (Compulsory) and switch on. It is very simple and works every time. You have the option to bypass the choke at a later time and usew the same LED tubes.
High Frequency control gear: If your fitting is using HF control gear then, it is best to view the manufacturers website to check for compatibility with your ballasts. Usually HF led tubes will work but from time to time they are simply incompatible and the manufacturers have not tested their tubes with all ballast types nor generations of ballasts so there is a risk of premature failure. We therefore recomend the removal of HF gear and that the lamps are operated in mains power.