I've just bought a couple of 5ft NVC Alaska (http://www.nvcuk.com/lighting/industrial/alaska-t8) fluorescent light fittings, 2 bulbs each. I'm assuming they're HF as they don't require a separate starter.
I bought Philips TD-L Super 80 daylight bulbs for them.
Anyway, when I first turn them on the lights pulse for about a minute or two until they've warmed up fully. By pulse I mean there is a pattern of light (3cm wide) and dark (2cm wide) strips, evenly spaced, move from one side to the other side of the bulb or from the outside to the centre. The whole thing starts off slow, builds up a bit of pace as it warms up and then eventually you get a super bright steady light (pretty much turned my garage into a tanning salon).
Anybody seen this behaviour before? My new Thorn HF light doesn't do this, but it's a single 4ft standard bulb. The ones I replaced with these were the old starter ones, but you didn't get to see this lighting display. However they were very old and did the whole flashing starting, buzzing loudly and one kinda flickered while in use.
Given that I've got two units and both do this, not sure if it's just cheap fittings and the ballast isn't up to the job or is it standard behaviour for this type of bulb?
I bought Philips TD-L Super 80 daylight bulbs for them.
Anyway, when I first turn them on the lights pulse for about a minute or two until they've warmed up fully. By pulse I mean there is a pattern of light (3cm wide) and dark (2cm wide) strips, evenly spaced, move from one side to the other side of the bulb or from the outside to the centre. The whole thing starts off slow, builds up a bit of pace as it warms up and then eventually you get a super bright steady light (pretty much turned my garage into a tanning salon).
Anybody seen this behaviour before? My new Thorn HF light doesn't do this, but it's a single 4ft standard bulb. The ones I replaced with these were the old starter ones, but you didn't get to see this lighting display. However they were very old and did the whole flashing starting, buzzing loudly and one kinda flickered while in use.
Given that I've got two units and both do this, not sure if it's just cheap fittings and the ballast isn't up to the job or is it standard behaviour for this type of bulb?