I hadn't realised that SELC - the photocell and ballast manufacturer - actually stood for anything. However at the recent ILP meeting their slides all had SELC - Smart Efficient Light Control on them.

They stated that a 70 Lux photocell with a 0.5 switch ratio (70 on, 35 off) runs the lamp it controls for 4150 hours a year. Changing to a 35/18 cell only saves about £2 in electricity for a 150W SON lamp on magnetic gear. If the cell costs £10 including labour to fit it, the payback period isn't that worthwhile. Ok to fit to new installations but you wouldn't swap thousands of cells out unless they were thermal ones and even then, you would be best to combine with a re-lamp.

Switching to later switching photocells is known in the trade as "trimming".

Ah... well in autumn/winter last year, York 'trimmed' all ther NEMA-socketed lanterns to use 55 Lux cells - only the minicell lanterns remain at 70.

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That's quite interesting... Maybe they should try 'trimming' around here bearing in mind quite a few lanterns switch on before the sun has even set!   Although in all fairness, most of the lanterns that do this use either two-part cells or minicells. Though a few have sensitive photocells too like a really eager Beta 79 I can see from my window that switches on 20 minutes before anything else!

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"I used to rule the world... Now I sweep the streets I used to own."
Remembering GEC.

Anyone know how to wire up a mincell (of which came out of a WRTL 2600 from the Poppleton depot). There are 3 wires, one is blue so thats neutral but there is a white one and a brown one.

Which wire goes to the lamp and which goes to the mains?

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From streetlighting to radio, dance through the night whilst the streetlights are glowing outside.

For all NEMA and minicells:

Blue = neutral
Brown = live supply
White = switched live to load

So basically, brown to the mains and white to the ballast.

white is always live out. Unless you have blue, black and brown/red, in which case the black is live out. It's odd that one, but I do have a minicell somewhere with a black live out!

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Thanks for your help, I've got it noted down now as well.

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From streetlighting to radio, dance through the night whilst the streetlights are glowing outside.

I have an Edinburgh style double refractor P107. The minicell has 2 wires, how does this get wired up. I asume there is something missing as there are extra hole for something this connects to. What do I need to make the cell function?

Should be 3 wires, live in (brown), switched live (usually red) and a neutral.