A rated line to line voltage for three phase ac machines line to ground voltage for single phase machines and rated direct voltage for dc machines or field windings.
Insulation resistance test results table.
The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms.
Do not allow the leads to touch during the test.
Historically many field electricians use the somewhat arbitrary standard of 1 megohm per kv.
The insulation resistance test is an electrical test which uses a certain type and level of voltage 500v d c.
Insulation resistance testing path can affect the test and reduce the insulation resistance reading.
Higher voltages are used to stress an insulation to a greater degree and thus obtain more accurate results.
Do not touch or move conductor during testing as results will be affected.
The international electrical testing association neta specification maintenance testing specifications for electrical power distribution equipment and.
The results obtained from ir test are not intended.
As a production test this test is often used as a customer acceptance test with minimum insulation resistance per unit length often specified by the customer.
Helps to plan for the future with respect to funding for.
A record shall be kept showing the results of such tests.
Recommended test voltages for routine maintenance insulation resistance tests of equipment rated to 4 160v and above.
B kv is the rated machine terminal to terminal voltage.
Suspend and isolate the test set leads in air as much as possible.
The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms.
With a little record keeping and common sense however you can get a good picture of the insulation condition from values that are only relative.
For low voltage installations i e.
For this reason care must be taken to properly prepare the cable to be tested.
For good insulation the resistance usually reads in the megohm range.
Short time or spot reading test.
Minimum acceptable insulation resistance for 600 v cable from 100 to 1000 feet.
Insulation resistance decreases in temperature or moisture.
Also acceptable values of insulation resistance depend upon the equipment you re testing.
Insulation resistance test results are dependant on a number of factors such as temperature and humidity.
However let s talk now about three basic types of insulation resistance tests using megger tester.
The measured resistance indicates the condition of the insulation between two conductive parts.
Values based on ieee std 43 2013.
The measurement of insulation resistance is a common routine test performed on all types of electrical wires and cables.
230v to measure insulation resistance in ohm s.
