I have a philips 11-14w electronic ballast  with 4 wires. It says that it can use a pls 11w but doesn't tell how to wire it.
How do you wire a 2 pin lamp to a 4 pin ballast?

My guess is that it means the 4-pin version of PL-S lamps. Those don't have integrated starter.

Yes, you will need to use the 4-pin version of the PL-S 11. It will say on the box of 2-pin lamps that you must use a magnetic ballast with them. The internal starter means they can't run on high frequency gear.

Although not formally rated, majority will work.
What you need is to identify exactly which pin on the ballast is which, namely which pin of the filament pairs (1 vs 2 and 3 vs 4) is the power connection and which goes to the resonant capacitor in the ballast.
You connect the lamp to the power ones. There are 4 possibilities (1-3, 2-3, 2-4, 1-4), one of them will work.

If none works, you have bad luck for either a ballast or lamp which do not work. I don't think there is any danger for the ballast nor the lamp, so it is just question if it will light or not.


If you open the ballast and take top and bottom photos of the board, there is high chance it should be possible to identify whether it will work or not and if so, the exact wiring.

I have found a philips branded (similar looking design too) 18w ballast that says to connect pin 2 and 4 for a 2 pin 18w pl-c.
Also, here 4 pin is called sh-9w instead of pl-s 9w, so that cannot be confused.
For now, I will try to use a magnetic ballast, but this would be more convenient.

So it confirms it is the selfoscillating type, with a few components added to (most likely) provide the protection against lamp EOL behavior.

The PL-S should be connected to the termibals labeled as 2 and 4.

Thanks, it works!
The lamps 'ping!', even with this ballast.