Philips MA 90

Lantern acquired in December 2019.

This lantern was removed from service on Wednesday, 18th December 2019; having been replaced with a Thorn Isaro Pro S 47 Watt LED lantern as part of Derbyshire's on-going replacement of conventional street lighting lanterns with LED equivalents. While I did acquire a geared MA 90 back in January 2003, this example was damaged after its bracket broke at the weld joint in blustery weather, and later, was cannibalised for parts. This new MA 90 was located around the corner from where the first example was removed, although, it is slightly older by manufacturing date. With thanks to E-ON Highways Lighting for saving the lantern for me.

After other MA 90s on my estate were replaced with Isaro Pros earlier in 2019, I expected the same to happen to this one before too much longer. Thus, I decided to photograph this example on the 1st September, in preparation for its expected removal. In my (slightly...) younger days, I would wait alongside this particular column for the school bus to arrive, and so there was a slight feeling of nostalgia towards this particular lantern for me.

The lantern was in typical condition for its age, with the GRP canopy appearing very grubby, even from ground level.

This night photograph was taken a little earlier, in April, as the side roads of my estate began to be relit with LED lanterns. The MA 90 that was to become mine is on the right of the picture.

The same column, a few days after being given the LED treatment.

A 20 Lux-rated Zodion ZCellLED operates the lantern.

This is the gear-in-head version of the MA 90; the inclusion of the gear adding to the overall length of the lantern - this version measures 1066 mm (3.5 ft) in length, which is 247 mm (9.7 inches) longer than the remotely-geared version. The lantern shell employed for the geared version was also used for the remotely-geared 135 Watt version of the MA 50.

A short section of the outreach bracket remained attached to the lantern. The reason for this became clear very quickly - the two grub screws securing the lantern to the bracket were seized. I managed to free the outer screw with a ratchet Allen key (but it still took considerable effort), but the inner screw remained stuck. Fortunately, I had asked that a second lantern be saved, and so I swapped the rear castings from the two lanterns, as the grub screws were free on the second example.

Oddly, the worst of the dirt and lichen growth is seen around the edge of the canopy, with the centre remaining relatively clean. I expect that this portion of the lantern became hotter during its operation, preventing the spores from settling.

The Royce Thompson Oasis 2000 photocell dates from January 1999, and is original to when the lantern was installed. I wonder whether the replacement lantern's cell will last twenty fact, I wonder whether the lantern itself will!

The NEMA socket is two years older, dating from January 1997.

The prismatic refractor bowl is held against the canopy with five clips, two of which are not designed to detach when loosened. This allows the bowl to hinge open during maintenance. A small plastic bung is situated at the back of the bowl, allowing any moisture within the lantern to drain out harmlessly. Earlier versions of the MA series did not feature this bung, resulting in a small pool of water becoming trapped in this area. The addition of the front bowl clip assisted in sealing the lantern more tightly against water ingress. Such is the design of the refractor layout in the bowl that the size of the lamp is minimised when viewed from the centre, but appears to be widened when viewed from the sides; thus, maximising the column spacing by spreading the beam as far in both directions as is possible.

This image demonstrates the hinge arrangement for the bowl. The lantern interior is somewhat spacious, with the gear components spread out quite liberally on the removable gear tray. Despite being in operation right up until the morning of the lantern's removal, the lamp carries the handwritten date of April 2013 on its side, and was made in February (almost) seven-year innings is miraculous for a SOX lamp running from dusk until dawn - and the lamp isn't even particularly worn!

The lantern's identity sticker was beginning to peel off from the inside of the canopy; this will be rectified as part of the restoration. The sticker informs us that the lantern was produced at Philips' Hamilton (UK) factory [HN] in February 1997 [7B].

The lamp control gear comprises a BSX 90L 32 ballast, SX 76 ignitor (both made in Holland) and L4010/07 10 F Power Factor correction capacitor dated 04/97, and made in the UK. The NEMA socket wiring burrows beneath the gear tray, although it connects into the main terminal block that is shared by the supply cable; thus, wiring out the photocell control is very straightforward in this lantern. The supply cable itself is surrounded by a flexible plastic sheath that serves to protect the cable against the heat of the ballast, as well as ensuring a tighter seal at the cable's entry point into the lantern is achieved.

The lantern was stripped down to its component parts on Saturday, 11th January 2020, in preparation for the much-needed restoration of the canopy. Notice the mark on the inside of the canopy, left by the heat emitted by the lamp during the lantern's twenty years of service.

Following comprehensive cleaning of the canopy, the identification sticker was re-secured to the inside.

The exterior was given several coats of Rust-Oleum cream gloss spray paint; the last of which was applied on Friday, 20th March 2020.

The rear casting and NEMA socket were reintroduced once the paint had dried sufficiently.

The internal components were reinstated next.

Meanwhile, the bowl was cleaned in warm, soapy water.

Next, the two parts were reunited, and the lantern attached to a waiting wall bracket.

The hinged operation of the bowl proved useful as the lantern was levelled on the bracket.

With the bowl back in place, the lantern was ready to be run for the first time in three months.

The (now) seven-year-old lamp struck immediately when the lantern was switched on; the photocell being wired out as part of the reassembly process. Owing to the lamp's age, the start-up colour was a deeper red than would be seen with a newer lamp - the neon base gas being in higher concentration within the arc tube than the argon / neon mixture would have been when new.

This, in turn, caused the lamp's warm-up to take longer too, but even so, the characteristic low pressure sodium glow had replaced the crimson neon glow after about ten minutes. As mentioned earlier, the bowl is designed to maximise the amount of light that is emitted from the sides of the lantern.

The beam intensity reduced at the front of the lantern.

The prismatic effect of the bowl's refractors made the lamp appear far narrower than it was in reality.

Lamp warm-up video:

Testing with my energy monitoring device revealed the following results; I was surprised at the capacitor's high Power Factor, given the lantern's age:

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
235.4 0.49 106 115 49.8 0.93 107.27 17.27 19.19%

Atlas Alpha 3 | ASD Micro Highway Diamond




© 2002 - English Street Lights Online