I'm converting a circa 2000 Hotpoint side-by-side refrigerator into a kegerator and fermentation bay for my homebrew beer. The fridge's original control circuitry was very simple, and had broken anyway, so I've completely removed it.

To cut a long story short, I'm using a programmable microcontroller to control the compressor, but I think I need to add a means of short-cycle protection to the code, as I'm not 100% sure that the compressor itself has any provision for this built into its hardware, and it makes the rest of the software somewhat more easy to write if I don't rely on any hardware mechanism.

Right now, my code causes the controller to wait 15 minutes between switching the compressor on or off. This causes a problem once the temperature in the keg side gets close to the target temperature, because turning the compressor on means that it's committed to running for at least 15 minutes, and it thus gets way colder than intended.

So, I have two questions:
1. For a typical refrigerator, how short does the minimum run/off time need to be?

2. Should the minimum run time be different from the minimum off time? For instance, can I make it sleep for at least ten minutes, but only run for a minimum of three minutes?

Thanks in advance.