Issues regarding the safe use of megohmmeters
Regarding the safe use of the megohmmeter, all power sources connected to the device under test must be cut off before measurement. Do not blindly use the megohmmeter to measure it. Do not use the megohmmeter until it stops rotating or discharges the device under test. Touch the terminals of the megohmmeter or the device under test with your hands.
1. When using a megohmmeter to measure insulation resistance near live equipment, at least two people must participate. The meter, connections, and human body should keep a sufficient safe distance from the live equipment, and the test wires cannot be pulled vigorously or the working range is expanded;
2. Before measurement, all power sources connected to the device under test must be cut off, and the device under test must be short-circuited to ground and discharged.
It is never allowed to use a megohmmeter to measure the insulation resistance of live equipment or equipment that has not been discharged after a power outage. This will not only fail to obtain correct measurement results, but also cause great danger or damage to people and equipment;
3. For equipment that may induce high voltage, you must not blindly use a megger to measure it until the possibility is eliminated;
4. Do not touch the terminals of the megohmmeter or the device under test before it stops rotating or the device under test is discharged.
Especially when testing equipment with large capacitance, the object under test must be short-circuited to ground and discharged, and then the megohmmeter can be stopped to remove the wires.
Note that when using a megohmmeter to measure insulation resistance, the workplace is often complex, surrounded by many high and low-voltage equipment running on electricity, as well as insufficient knowledge of the performance characteristics of the equipment under test and other hazards.
If you do not take it seriously, it will cause serious harm to the safety of people and equipment when measuring insulation resistance, so you must be very careful.
