When I have been looking at 4 pin CFL light bulbs on the internet that are intended for the North American market, I have noticed that many manufacturers state that 4 pin CFL lamps are NOT compatible with magnetic ballasts whatsoever at all and will only operate on electronic ballasts. In fact, it is actually possible to run some 4 pin CFL lamps on magnetic ballasts as long as you wire an external starter across 2 of the pins or if you use a magnetic rapid start ballast as in the case with some PL-L CFL lamps.

I am interested in knowing why so many North American manufacturers often falsely claim that all 4 pin CFL lamps are incompatible with magnetic ballasts?

Here is Sunlite’s magnetic ballast incompatibility claim for 2G11 PL-L CFL lamps:

“Linear Plug-Ins:
These lamps consist of either 2 separate parallel tubes, a single U-shaped tube, or two parallel tubes joined near the top of the bulb, and have 4 pins on the base lined up in a row. All linear plug-in fluorescent light bulbs operate on electronic ballasts. 2G11 bases are utilized for all linear plug-in fluorescent light bulbs (regardless of wattage). They are found in troffer fixtures, wall washer fixtures, retail track lighting, and menu boards.”

In a technical sense, 18w, 24w, and 36w PL-L CFL lamps were originally designed for magnetic preheat ballasts utilizing an external starter while 40w and 50w PL-L CFL lamps were originally designed to operate on rapid start ballasts in North America.

This is true also with the European 4 pin CFLs that states that they are suitable only for electronic ballasts and emergency ballasts.

Some European 4 pin CFL lamps like PL-L 18w, PL-L 24w, and PL-L 36w lamps were originally intended for magnetic preheat ballasts, but other lamps like the 4 pin PL-T, PL-C, PL-R, PL-H lamps are only intended for electronic ballasts and will have a very short lifetime on magnetic ballasts.