GEC Z9484

Lantern acquired in November 2009.

Thanks to Stephen Palmer for this lantern. Although non-existent in Derbyshire, Z9484s were once a common sight on side streets in the Stafford area; all have now been confined to history owing to Staffordshire's Street Lighting PFI replacement work.

The Z9484 is a highly streamlined design, although its smooth, flowing contours are distorted here with the addition of a Royce Thompson P42 photocell detector to the canopy. The hinged polycarbonate bowl has yellowed slightly over time. An unusual feature of this lantern is that the sealing gasket is attached to the bowl, rather than being fixed to a recess within the canopy.


The lantern measures a relatively short 23 1/2 inches (597 mm) in length, and is 5 3/4 inches (146 mm) in both depth and width.


Original incarnations of this lantern were designed for running a 60 W SLI/H linear sodium lamp, with the lantern being known as the 'Clearside' Z9494/5 at this time, but 35 / 55 W SOX options (such as this example) were produced later. The lantern was a Z9494 or Z9495 depending on the type of lamp control gear employed; in the former case, a starter switch was fitted in the lantern, with the lamp wired in a conventional 'fluorescent' method. In the latter case, the lamp ran on Instant Start gear.


The lamp support is positioned some distance from its fixing screw; this being because the fixing point for the original SLI/H lampholder was located here. Had the lamp support been positioned directly below the fixing screw, 35 W lamps would be too short to reach it.


Restoration of the lantern commenced in May 2018. The first task was to try to free the two jammed 5 mm grub screws that clamp the lantern to a bracket. One of these worked free with some heat from a blowtorch, but the other remained resolutely stuck in place and had to be drilled out and the resultant hole re-threaded. Once this was complete, the lantern was stripped - this took all of about one minute!


The faded internal white paint will be renewed.


The canopy returned from being bead blasted on Friday, 6th July 2018. I decided to leave its exterior unpainted; hence, the slightly matte appearance of the cleaned aluminium.


As mentioned above, the internal white paint was renewed, however.


With that, the lantern was re-assembled and attached to a wall bracket. The glow seen in the picture below is from the ELECO HW-747, which was running on test at the time.


Although able to accommodate a 55 W lamp, I elected to run the lantern with a 35 W lamp instead, as the lamp support is positioned closely enough to the lamp for this to be an option.


Lamp warm-up video:

Testing with my energy monitoring device revealed the following results:

Test Voltage (V) Current being drawn at full power (A) Measured wattage (W) Apparent Power (VA) Frequency (Hz) Power Factor True Power (W) Difference to rated wattage Percentage Difference
245.1 0.29 60 71 49.9 0.84 59.71 24.71 71%

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