Does an burnt out florescent lightbulb use the same amount of power as a new one does

Question

Does a burnt out florescent light bulb use the same amount of energy as new florescent light bulb does

Answer 1

No, a burned out fluorescent tube doesn't use any power at all. It is an "arc light", and if the arc has not struck, then there is zero current.

Power is Watts = Volts x Amps. If Amps is 0, then Watts is 0.

If the filaments at the end are glowing (the pre-heaters) it's using a couple of watts at most.

There will be a few watts of load in the ballast, depending on the technology of ballast (a lot more for an old transformer-based "magnetic ballast", very little for a modern electronic ballast).

Answer 2

It's more about the ballast than the lamp. Most modern ballasts are electronic which can sense how much power is demanded and only provide that amount to flow. Old-style autotransformer type ballasts, because of their design, let current flow whether there is a lamp in the fixture or not.