Accident Cause

Something exploded.

This is not an appropriate question for an anonymous forum, in my opinion.

Can you give more detail of just where and how the compressor or its housing broke?

You need a technician to do a forensic investigation....capacitors can sometimes explode....wires can cross phase, terminals can blow out...speculation without detailed examination is useless....do you have pictures?

Detail which i got is, technician are using refrigerator compressor for pressure test and vacuum.

That is a common practice, but tells us nothing about what may have happened...

Simply, during the test period the equipment was subjected to a pressure that it was unable to sustain.

• Pressure testing should be done using incompressible fluids. Water at ambient temperature is a good example of a suitable fluid, being relatively benign to both operative and environment. The Engineer/Surveyor for the company responsible for providing burst/collapse indemnity insurance cover is always the best point of reference. This individual's name is on the pressure test record for the equipment that is being tested.

lack of information, we don't know. was a torch or electricity involved?

Why do I suspect that it was filled with R290? Call your lawyers and forensic engineers.