Crompton Crompack

Acquired in October 2020.

This fitting was found fly-tipped by the side of a local road; presumably, in the hope that some scrap metal fairy would find it and make it disappear, as the individual responsible was far too lazy to consider disposal in a more suitable manner. Fortunately, in this case, that is exactly what happened, as I decided to give it a loving home! I had thought that it would be a stripped-out carcass, and so was surprised to find that it was almost completely intact, and more surprisingly, showed no signs of failure or excessive dirt. The Crompack was available in 2 ft (600 mm), right up to 8 ft (2400 mm) - this 5 ft (1500 mm) example is, therefore, about the 'middle' sized produced.

Prior to being brought indoors, the freshly-acquired batten was given a clean with warm, soapy water, just to remove any dirt that had accumulated during its brief spell by the side of the road. The fitting may have had a diffuser originally, though if it did, there wasn't one present upon its discovery by me.

A label at the end of the fitting states that it is made to BS 3820 (Specification for Electrical Lighting Fittings), which was introduced in 1964 and superseded by BS 4533-2.1 in 1976, giving an approximate age of the fitting. The two T12 lampholders are sprung, allowing the lamp to be held securely under normal circumstances.

The fitting is made of extruded steel box section, with a steel cover over the wiring and gear serving as a rudimentary reflector.

The lampholders fit into grey plastic end caps.

The insides of the lampholders contain the Crompton Parkinson logo.

Loosening two slotted cheese head screws allows the cover to be removed, granting access to be gained to the internal wiring. Oddly, the connector block is missing, though all of the other wires and components are in place. Originally, the wiring would have been taped to one side of the casing; however, the tape has lost its adhesive properties over time, causing the wiring to flap about inside the fitting.

The fitting's name is stamped on the inside of the extrusion, along with the inspection code 3262 385A.

The C164 switch-start ballast is in good condition, even though it appears to have clocked up a high number of hours in its lifetime. This may have been made by Philips under licence.

(Possibly) the fitting's original starter was still installed. This too looked to be a Philips product, having been made in the Netherlands. The starter carries the apparent date code '4Y', although 'Y' is not used in the Philips date coding system.

A Pye C548 5.5 F Power Factor correction capacitor completes the circuit components. The date code on this looks to be 'L4', which, if it follows the Philips system too, would suggest that it was made in the November in a year ending in '4' where the decade was even. Given the British Standard to which this was made (BS 4017:1966), it cannot be 1964, and as the internal wiring is brown and blue, rather than red and black, I am inclined to ignore the Philips system to some extent, and suggest that the fitting dates from 1974 instead - the change of colours occurring in 1969, although for fixed wiring in the UK, the change didn't commence until 2004. The earth wire to the fitting is identified with solid green sleeving too - had the fitting been installed after 1977, this would have been green and yellow.

Conveniently, I had a 1970s' Thorn 65 Watt lamp that was perfect for using in this fitting. Thus, I rigged the Crompack up to a temporary test lead, switched on, and...nothing happened! The three amp fuse in the test lead plug was found to have blown, which made me decide to disconnect the capacitor, on a hunch. Sure enough, this was the culprit, as once a new fuse was fitted, the Crompack sprung into life. I assume that the faulty capacitor was the reason that the fitting ended up being thrown out, as it would have caused the fuse or Miniature Circuit Breaker protecting the lighting circuit wherever the fitting was installed to blow or trip too. A replacement capacitor is seen beneath the lamp in the picture below.

The rather sickly glow produced was the result of the halophosphate 3500 K colouring of the lamp.

The dual wattage rating of the lamp indicates that it was suitable for use on older fittings that employed an 80 Watt ballast, as well as on newer fittings (such as this one) that employed a more efficient 65 Watt ballast.

Testing with my energy monitoring device (prior to replacing the capacitor) 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
245.9 0.52 76 128 50 0.6 76.72 11.72 18.03%

The Crompack was installed on Friday, 16th October 2020. As is typical with fluorescent lighting, the picture is under-exposed - in reality, the lamp is much brighter.

The Thorn franking is just visible behind the Philips MA 50.

Operation video:

Fitzgerald (Light Ring) Bulldog | Thorn Diffusalux




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