Do not touch or move conductor during testing as results will be affected.
Insulation resistance test results table.
Insulation resistance test results are dependant on a number of factors such as temperature and humidity.
Ansi neta mts 2015 table 100 11 insulation resistance test values rotating machinery for one minute at 40 c.
Minimum acceptable insulation resistance for 600 v cable from 100 to 1000 feet.
Insulation resistance decreases in temperature or moisture.
The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms.
Higher voltages are used to stress an insulation to a greater degree and thus obtain more accurate results.
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.
Why perform insulation resistance testing it s the law 33 cfr 208 10 f 1 megger tests of all insulation shall be made whenever wiring has been subjected to undue dampness and otherwise at intervals not to exceed one year.
Short time or spot reading test.
A record shall be kept showing the results of such tests.
The measured resistance indicates the condition of the insulation between two conductive parts.
Also acceptable values of insulation resistance depend upon the equipment you re testing.
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.
The most common voltages are 500v and 1 000v.
Historically many field electricians use the somewhat arbitrary standard of 1 megohm per kv.
For good insulation the resistance usually reads in the megohm range.
The insulation resistance test is an electrical test which uses a certain type and level of voltage 500v d c.
The results obtained from ir test are not intended.
Helps to plan for the future with respect to funding for.
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.
Values based on ieee std 43 2013.
230v to measure insulation resistance in ohm s.
Recommended test voltages for routine maintenance insulation resistance tests of equipment rated to 4 160v and above.
For this reason care must be taken to properly prepare the cable to be tested.
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.
However let s talk now about three basic types of insulation resistance tests using megger tester.
The measurement of insulation resistance is a common routine test performed on all types of electrical wires and cables.
Do not allow the leads to touch during the test.
Insulation resistance testing path can affect the test and reduce the insulation resistance reading.
