We are often asked if installers can fit T5 adapters to fluorescent fittings which have emergency function.
If the fittings have some tubes which are NOT controlled by the emergency system (and are standard switch-start) then you can easily convert the switch-start side (just bypass the power-factor capacitor as usual).
But the emergency tube 'side' of the old fitting usually doesn't supply the right power for running a T5 tube adapter without modification of some kind. While we have quoted for some sites a special T5 adapter with no internal ballast, and fitting a specially-made emergency pack complete with external high-frequency ballast, it costs a lot so tends to provide poor payback.
If you can leave the small number of emergency tubes un-converted please remember that our T5 adapters use less power than typical plastic end-cap style T5 adapters (for equivalent ground level light due to the bright silver integral reflector) so across the site you might even find energy-savings are as the customer first estimated a T5 conversion would deliver anyway.
But if it's critical to convert all tubes to emergency you could suggest fitting new bulkhead emergency light-fittings. These are cheap at about £20 each.
Using a non-maintained (always 'off') version saves a little energy too.
Bear in mind that the original emergency battery packs may have been on their last legs anyway so this is a solution that improves the emergency lighting system.
Then when you fit the T5 tube adapters to what was the 'emergency' side of the light-fitting, the qualified electrician would just bypass all the control gear, so full mains voltage is delivered to the T5 adapters.
I'm referring to the ClickSave models. A few T5 adapters may need a different approach.