"Andy Burns" wrote in message
...
On 18/08/2007 18:59, Marsbar wrote:

Switch on only when required. What made you think that switching a
fluorescent light on and off wasn't a good idea?

It was either a common misapprehension, or used to be different with older
tubes. I certainly remember an "order" going around school in the early
70's to NOT switch off lights during break-times as it took more
electricity to re-start them, than to leave them on for 20 minutes.

It was a complete redherring then and still is. Yes the current is higher
in order to ignite the tub, but given it lasts for a second or so. As long
as the tube is switched off for over, say 5 seconds, there'll still be a net
saving.