Philips MI 26

The MI 26 was the name provided to the UK version of the Philips F/XGS 103 lantern, from its introduction in the late 1980s, until Philips standardised on the F/XGS 103 name in the late 1990s; the 'MI' prefix meaning that the lantern was intended for use on MInor roads, and the '26' suffix showing that the lantern was able to accommodate a 26 W SOX-E lamp (the same physical size as a 35 W SOX lamp). Presumably, the use of 35 W lamps in these lanterns proved more popular than the use of 26 W lamps did; hence the retiring of the MI 26 name. The 18 W version of this lantern is not officially listed in UK catalogues, however, a conversion to this wattage was still possible, owing to the presence of fixing points for the lamp support in two places along the gear tray. This particular lantern features such a conversion.

There is no identification on this lantern to explain which it should be named, but the NEMA socket is dated 1992, so I'll assume that it is an MI 26.

These lanterns are easily identified, thanks to their GRP canopy (complete with removable rear section) and polycarbonate bowl that hinges forwards for maintenance, and is secured by a sprung rear clip.

The Philips logo is incorporated into the slightly raised section of the canopy that also incorporates the lantern's NEMA socket (where fitted).

Removing the rear section of the canopy reveals the V-shaped clamp that secures the lantern to its bracket.

The bowl features refractor prisms moulded into both sides of the plastic - compare this to the main rival lantern for the MI 26, the Thorn Beta 5, in which the bowl refractors are only incorporated into the inside of the bowl. Earlier versions of the Philips lantern, the MI 50 and MI 55, featured an identical bowl to the MI 26, although the lampholders on these lanterns were positioned at the end closest to the bracket. This position was revised for the introduction of the MI 26, owing to the problem of premature SOX lamp failure on lanterns fitted to brackets with steep outreaches - operating SOX lamps cap-down in a position greater than 20 degrees above the horizontal can cause the liquefied sodium to trickle down the arc tube, and short out the electrodes.

Removing the bowl reveals the shorter 18 W lamp, which only takes up about two thirds of the available space below the reflector.

Without the lamp fitted, the two positions for the lamp support are visible. The two bolts that tighten the V-shaped clamp's hold on the bracket can be seen on the left, through gaps in the reflector.

The gear for MI 26s is usually housed inside the canopy (as it is with my later FGS 103 lantern); however, as this lantern is an in-house conversion, the gear is instead fitted to the other side of the reflector. The ballast contains its own ignitor circuit; hence the lack of a separate ignitor in this lantern.

With the lantern powered up, the shorter length of the 18 W lamp becomes obvious.

Lantern warm-up video:

Testing the lantern 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 (W) Percentage Difference
240.9 0.14 27 34 49.9 0.83 27.99 9.99 56

Philips MI / F/XGS Lanterns in the Collection

FGS 103

FGS 104

MI 8

MI 26

MI 50

MI 55

MI 80

XGS 103

XGS 104

GEC Z8896 | Philips MA 50




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