What is an acceptable reading on a megger?
Anything reading between 2 megohms and 1000 megohms is usually considered a good reading, unless other problems have been noted. Anything less than 2 megohms indicates an insulation problem.
What is the safety precaution or procedure of using megger tester?
Megger Test Safety Precautions Use megger test on high-resistance measurements only, such as insulation measurements or to check two separate conductors on a cable. Never touch the test leads while the handle is being cranked. De-energize and discharge the circuit completely before connecting a megger test.
What is the minimum acceptable value of insulation resistance?
The rule states that insulation resistance should be approximately one megohm for each 1000 volts of operating voltage, with a one megohm minimum. (By following this rule, a motor rated at 2400 volts should have a minimum insulation resistance of 2.4 megohms).
What precaution must be taken when testing the insulation of generator cables?
Connections for testing the insulation resistance of a power cable. When testing cable, it is usually best to disconnect at both ends in order to test the cable by itself, and to avoid error due to leakage across or through switchboards or panelboards.
How many ohms is an open circuit?
infinite
In an open circuit condition, the current is zero (I = 0). Hence, for any value of voltage, the resistance is infinite in open circuit conditions.
What are the safety aspects of working in an insulation test?
Use protective gear. Use insulated tools, Wear flame resistant clothing, safety glasses, and insulation gloves, Remove watches or other jewelry, Stand on an insulation mat. 03. Never connect the insulation tester to energized conductors or energized equipment and always follow the manufacturer’s recommendations.
When using a Megger you must avoid touching?
While measurement of insulation resistance by megger, both leads at the same time must not be touched. When a megger is used, the generator voltage is present on the test leads. This voltage could injure you or damage the equipment you are working on.
What are some of the safety precautions when dealing with high voltage electricity?
Be sure to carefully observe the following safety precautions.
- Always connect a ground wire.
- Do not touch high voltage areas.
- Cover high voltage areas.
- Share an awareness of danger.
- Perform operations with your right hand.
- Turn off the power before touching equipment.
- Pay attention to electric charge in cables.
What is the minimum acceptable reading for insulation resistance on a 230V circuit?
Test voltage 500v for 230v or 400v installations or circuits with a minimum insulation resistance of 1 M ohm (1000,000 ohms).