Unusual behaviour in a fridge compressor?

A few times a day a fridge (Indesit INTS1610) is shorting live to ground and tripping the breaker. I am trying to figure out whether it is the start relay or the compressor itself. I was monitoring the power consumption of the compressor. On power on, the compressor drew about 550 watts for 15 seconds or so, then dropped to 10w (probably just the condenser fan) for about a minute. Then the compressor tried to start again and drew about 200w, dropping over about 10 seconds down to 75w where it stayed from then on. The first time I check it, it did trip the breaker. Then after that 4 more starts without tripping the breaker. There was some cooling happening in the fridge – back wall cold and condenser getting quite warm.

Any ideas?