100W or 125W 8ft T12 fitting

[Graham.]

How can I tell if a traditional 8 foot (glowswitch + choke) fitting requires a

100 or a 125 Watt T12 tube?

[Tabby]

uires a 100 or a 125 Watt T12 tube?

open the cover & look at the choke or other ballast

[chris French]

In message , Graham. writes

As an aside, according to the chap in a local elec. wholesalers 8 ft tubes production is being stopped and they are going to disappear off the market.

no idea if it true though, since I have none, not bothered to follow it up.

[Andrew Gabriel]

100 or a 125 Watt T12 tube?

You can always use 100W tube (if there's also a glowswitch) as it's designed to be retrofitted into a 125W switch-start fitting.

I haven't tried 125W tube on 100W ballast, and I would expect that would work too, but as someone else said, pop the cover off and look at the rating on the ballast.

The 100W tube is more efficient and probably better colour rendering. The 125W tubes will certainly vanish off the market as they don't meet future EU efficiency requirements. The 100W tube is an energy saver retrofit, but being the first one invented, it predates the reduction to T8 which happened with all the subsequent shorter energy saver retrofits which came along.

[The Other Mike]

Sounds a load of bollocks to me, there are thousand of industrial units that still use them.

[chris French]

In message , The Other Mike writes

just passing on what I heard.

but seems there might be some truth in it. A quick google turned up this:

"The 8 FT 100w and 125w tubes are becoming obsolete - we can still source them but two of the major manufacturers have stopped making them. We would advise replacing them if possible (you could use a 6ft twin fitting for example) as we dont know how much longer we will be able to source them. "

[The Other Mike]

Oh bugger :(