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Clearside 8254/5
For Osram Fluorescent Tubes

Specification Clearside 8254/5

Use
Side road lighting; the lantern is designed for mounting at heights between 15 ft and 18 ft and at a spacing of 100-120 ft.

The lantern is very suitable for use on housing estates, especially in new towns.


Tubes
Two 2 ft. 40W Osram fluorescent tubes


Mounting
The Z8254 side entry lantern requires not less than 5 in. of horizontal unthreaded 1.1/4 in. B.S.P. When fully home two 7/16 in. Allen-type grub screws grip the barrel. The design allows for the lantern to be elevated slightly if this is required to add to the appearance of an installation.

The Z8255 top entry lantern requires 2 in. of threaded 1.1/4 in. B.S.P.


Lantern Body
One-piece silicon aluminium alloy die-casting. The gear and wiring necessary to operate the tubes is fitted to a removable tray screwed to bosses in the body casting. The body also carries the two lampholder supports.

An earthing screw, porcelain terminal block and porcelain cable cleat are provided.


Optical System
Light control is obtained by two 'Perspex' refractor plates. The prismatic sides of the plates are bonded, one to each inner side of a 'Perspex' bowl. Both inner and outer surfaces of the bowl are smooth for easy cleaning. A white over-reflector is a secondary component of the optical system. The inside of the body and the ends of the enclosing bowl are given a matt finish to diffuse stray light and give the lantern a pleasing appearance. The enclosing bowl is held to the lantern body by stainless steel toggle clips and toggle hinges. A tropicalised felt gasket between the body casting and bowl ensures a weatherproof seal when the lantern is closed.


Weathering Finish
The alloy used is specially selected for its resistance to corrosion. Further protection is obtained by the use of pre-treatment primer and silver top coat, stoved on.


The Z8254 lantern. The bowl has been lowered to show the tubes.




The polar curve is based on an average tube life from two 2 ft. 40W Osram white fluorescent tubes (2880 lumens average).

Directional intensity ratio2.0:1
Light above horizontal25%
Light output ratio80%
Lumens in the lower hemisphere    1730    


Light distribution data are given for the guidance of the lighting engineer and represent the average results of laboratory tests on a number of lanterns taken at random from stock. The data are based on the tube characteristics stated; if the latest tube efficiency is different, the candela or lumen values should be calculated in direct proportion to the relative tube lumens.


Lantern weights: Z8254 Complete with gear: 25lb (11.3 kg)
Lantern weights: Z8255 Complete with gear: 23lb (10.4 kg)


Part of an installation of GEC Z8254/5 lanterns at Richmond and Kew, Surrey