ALONG WITH
MEGGER TEST FOR
CHECKING OF
MOTOR ,WHY WE
MEASURE FOR
RESISTANCE AND
INDUCTANCE?
Answers were Sorted based on User's Feedback
Answer / erharisheee51
i Guess Megger test means Insulation Resistance test ..using
Megger test itself we can able to find the insulation
strength interms of resistance only ..
so what is that question ? please be clear that resistance
and megger test are similar ..
and remaining inductance test i don't know that ..
is it correct , Please clarify
Is This Answer Correct ? | 10 Yes | 3 No |
Answer / ramesh
Insulation test for checking of winding healthy condition,
If any short circuit inside area, the motor cannot operate.
So that before energised motor, insulation test to be done.
Is This Answer Correct ? | 8 Yes | 2 No |
Answer / stan grzegorski
Megger (or Insulation) test will test ISULATION ONLY . A "
Megger" is one manufacturer of insulation testers . This (&
most other) insulation tester also has a low resistance
range for measuring & COMPARING motot winding
resistance .Insulation resistance is normally measured at
twice the RMS line voltage minimum , (For 240 Volt rated
equipment the 500V setting is used )DO NOT USE IT IF THERE
ARE SESITIVE ELECTRONIC COMPONENTS IN CIRCUIT . ( You WILL
destroy them ). BE VERY AWARE !! The 500 V & 1000V settings
on these instruments is not what they are measuring ,IT'S
WHAT THEY ARE SUPPLYING , & IF YOU ARE PART OF THE CIRCUIT
THAT IS WHAT YOU WILL BE SUPPLIED WITH !The output current
is limited to a safe level , but if there are any
capacitors in the circuit , THIS CAN BE MULTIPLIED MANY
TIMES to a dangerous level.Specifications for insulation
resistance to earth ( Ground /Chassis ), is 1 M ohm ( 1 Meg
ohm , 1,000,000 ohm ), but in reality if isulation
resistance is 10 Mohm or under , the equipment may need
drying out , or is on its way to the bin . The low
resitance range is for measuring continuity , in this case
that the motor windings aren't broken , normally in the
order of a few ohms , & on larger motors less than 0.5
ohms .Inductance is an electromagnetic parameter which
affects AC or varying DC current & is dependent on the
frequency of the AC current or the RATE OF CHANGE of DC
current . ( Higher frequency = Higher inductance ) > In
most AC machines (Motors , transformers etc.)the Inductive
reactance is cosiderably larger than the resistance , &
measuring inductance can identify faults which would be
practically impossible using resistance measurements .
Is This Answer Correct ? | 1 Yes | 0 No |
Answer / amit
My senior while
checkin ht
motor ,first he
measured
resistance using
micro ohmmeter
and he got 25m
ohms after tat he
meggered it
getting 5Gohms...
So i asked this
question...
Is This Answer Correct ? | 1 Yes | 1 No |
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