I recently bought a "maintained" emergency luminaire, which has battery backup (obviously!) and an 8w fluorescent tube. I've noticed that the tube's filaments are glowing gently all the time the power is on (can be seen when the room light is less than bright) and feel slightly warm. Is this usual? Does it waste much power? What's the reason for it?
I understand "non-maintained" (just live feed, comes on when it fails) and "maintained" (live and switched-live, comes on when power fails or switch is on) but is there a scheme where the light comes on when power fails only if the switch is in the on position? That way it wouldn't bother coming on when there's a power failure when it's not dark!
(And I've always wondered why "maintained" is the name - what is being maintained?)
Cheers,
Howard
I understand "non-maintained" (just live feed, comes on when it fails) and "maintained" (live and switched-live, comes on when power fails or switch is on) but is there a scheme where the light comes on when power fails only if the switch is in the on position? That way it wouldn't bother coming on when there's a power failure when it's not dark!
(And I've always wondered why "maintained" is the name - what is being maintained?)
Cheers,
Howard