On 01/12/2017 10:20, Fevric J. Glandules wrote:

I guess it makes economic sense to do so now that the tube has blown.

I have partially dismantled the existing fitting.

Do these things have standard mounting holes so that a new batten
fitting would slot into place?

Usually. Some are designed as straight drop in replacements. Others will
require some wiring changes to the fitting to take the old magnetic
ballast out of circuit. Follow the instructions with your lamp carefully.

The old one probably dates back a few decades.

Also, why on earth are there no less than four twin-core and
earth cables coming out of the ceiling?

You would normally expect at least 3, however it may be you have a
branch in the circuit at that point, with a feed to an additional lamp
being taken from the position.

See here for an illustration:

http://wiki.diyfaq.org.uk/index.php/...Loop-in_Wiring

(you may have more than one "Supply cable to next light fitting")

(All the cores are wired together in terminal blocks wrapped
in tape. Looks like a bit of a bodge job).




--
Cheers,

John.

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