When dust, grime and mineral scales build up on the condenser coil, the AC can't expel enough heat from the system and it's forced to run constantly trying to cool your space. The increased pressure and temperature can cause the compressor to overheat and fail.
When your Hitachi air conditioner's refrigerant lines become blocked or damaged, the first thing you'll notice is that the unit is not cooling as effectively. If the problem is not fixed, once again the increased pressure and temperature cause overheating and Hitachi AC compressor failure
If your system's refrigerant lines develop holes or cracks, the AC leaks refrigerant. After a while, the level becomes so low that the compressor has to work harder to pump enough refrigerant through the system to cool your space. The strain can eventually cause the compressor to break down.
A line that's too large or too small for your system can cause premature Hitachi AC compressor failure
If a less-than-qualified person works on your Hitachi AC and inadvertently adds too much refrigerant, or even the wrong type of refrigerant, it can be a deadly mistake for the compressor.
An electrical failure can result in a buildup of acids that cause a great deal of damage to other parts in addition to the compressor.
To take the heart comparison a step further, think of your Hitachi air conditioner's oil lubricant like the blood in your body. If there's not enough, the system can't work properly and all kinds of problems can result, including AC compressor failure. When your system is regularly maintained by a trained AC professional, he will check the lubricant levels and the condition of the oil pump to prevent this problem.