Sounds as though it recently has a defrost. When defrost heaters fail, they either open circuit or short to earth and trip the earth leakage or a circuitmikeref 11-02-2016, 09:07 AM
Go on Google and type in Why Compressors Fail re Glenn Moore . There are 9 articles in the series . These may help you find the problem
Yep, we'd come to the conclusion it'd have to be a refrigeration course
So spent two hours on site today going through the 'official procedure'