Cause of damage without energy isolation
Not stopping the machine or equipment
No energy is really cut off
It doesn't eliminate the residual energy
Accidentally turn on a device that has been turned off
The work site is not actually cleaned up before restarting
Pressure system test confirmation
Make sure the voltmeter is calibrated
Set the voltmeter range at the right voltage.
Test a strange voltage.
Check the hazard area with a voltmeter and confirm that it is zero voltage.
Measure the unfamiliar voltage again to confirm that the voltmeter is working properly.
Common system isolation principles
Hydraulic, pneumatic, steam drive - isolate all inlet and outlet lines
Engine drive - isolated fuel supply system and start-up system
Power drive - isolate the main circuit of the power supply
Isolate potential mechanical movement risks