Security Lighting ST3000N/ICEL

Bulkhead acquired in January 2021.

This emergency lighting bulkhead was purchased as unused old stock from eBay, and is unusual in that it employs a miniature filament lamp as its main light source in the event of a power failure, rather than a low wattage fluorescent lamp, as might be expected.

The bulkhead was contained within its original box - its age being immediately apparent with the 0703 area code for Southampton (this becoming 01703 in 1995, and 023 more recently), along with a Telex contact method too - no website or email address! The 'Security Lighting' company appears to be defunct these days too.

The bulkhead comprises a black polycarbonate housing and translucent white cover. It measures 265 mm × 135 mm × 85 mm (10·4 inch × 5·3 inch × 3·3 inch), which is considerably larger than it needs to be for housing such a tiny light source - I wonder whether a 6 Watt fluorescent version was produced too.

This close-up of the product label includes the mention that the bulkhead was tested for the Industry Committee for Emergency Lighting, which is just as well, given that 'ICEL' forms part of the product code! An alternative code is NM/3T, which (perhaps) translates as Non-Maintained, three hour, tungsten lamp.

Six pre-drilled holes in the rear of the fitting allow it to be wall or ceiling-mounted, while a variety of circular connector box sizes can be accommodated, thanks to windmill-like fins surrounding the main cable entry hole. Alternate cable entry holes are moulded into the two short sizes, but would require drilling out before they could be utilised.

The cover is translucent enough to conceal the centrally-located lamp, but just transparent enough for the moulded diffuser patterning to be visible.

The cover pulls away from the main body, revealing the lamp screwed in to its Miniature Edison Screw (E10) lampholder. A single red LED protrudes through the side of the reflector; when lit, this provides an indication that the mains electricity supply is live, and that the back-up battery should be charging.

The reflector hinges downwards, once a small screw is loosened. On the reverse side is a circuit board that runs the charging circuit.

Stamped faintly on the top-left corner is the date that the fitting was tested - the 5th January 1991; spookily, the fitting entered the Collection on the 7th January 2021!

Two 1.2 Volt 'D'-type batteries are wired in series and run the lamp in the event of a mains power failure loss. Below the positive wire is a warning that the batteries should be replaced within four years of installation, with a space left above for the commissioning date to be written on in pen by the fitting's installer.

Remarkably, despite thirty years having passed since the fitting was produced, as soon as the batteries were connected, the little lamp glowed quite brightly.

The cover diffused its output without reducing light levels significantly.

Finally, the electricity supply was switched on, causing the filament lamp to extinguish and the LED to illuminate.

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