In article ,
Adrian Godwin writes:
What are the factors affecting the voiltage rating of a CFL or other
electronically-ballasted lamp ?

For some time, I've been trying to find a 110V circline lamp & holder
for a particular fitting. I'm in the UK, and even 240V circlines aren't
very common. The equipment has a 240-110V transformer that I didn't want
to rewire.

Eventually, I decided to try a 240V CFL - and it strikes and runs
perfectly (not sure whether it's running dimly or not, but it's bright
enough for the application).

Is this OK, or likely to be overstressing the ballast, by taking more
current for a given power than the 240V circuit would normally need ?

Have you checked the ballast rating? I bought some electronic
ballasts for a kitchen lighting project a while back. Some of
them were rated something like 95-277V input.

If you are underrunning the tube and the ballast wasn't
designed to do this, you will shorten the tube life.
It's difficult to predict how a ballast will behave when
operating outside its design rating.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]