What is polarisation index value?.(pi value)
Simple & brief definition of polarisation index?..

Answers were Sorted based on User's Feedback



What is polarisation index value?.(pi value) Simple & brief definition of polarisation index?....

Answer / kapil mishra

PI is a variation of the IR test. It is the ratio of IR
measured after voltage has been applied for 10 minutes (R10)
to the IR measured after one minute (R1), i.e.

PI = R10/R1
Low value of PI indicates that the winding may have been
contaminated with oil, dirt etc or absorbed moistures. In
the test, a relatively high DC voltage is applied between
the copper conductor and the stator or rotor core usually
between the winding and ground as the machine core & body
are grounded)

Is This Answer Correct ?    10 Yes 0 No

What is polarisation index value?.(pi value) Simple & brief definition of polarisation index?....

Answer / v.senthilkumar - skpcl

The ratio between IR value for 10 minutes to 1 minute.

Formula (PI) = Resistance Value 10 Min after
start/Resistance value 1 Min after start. (IR 10min / IR
1min)

The recommended minimum values for PI are based on the
thermal class of the insulating materials and apply to all
insulating materials regardless of application per IEC
60085-01:1984. The PI test is not applicable to non-
insulated field winding. The recommended minimum value for
PI are as follows:

Class A Termal Class Rating = Min PI is 1.5
Class B Termal Class Rating = Min PI is 2.0
Class F Termal Class Rating = Min PI is 2.0
Class F Termal Class Rating = Min PI is 2.0

Is This Answer Correct ?    8 Yes 2 No

What is polarisation index value?.(pi value) Simple & brief definition of polarisation index?....

Answer / sridhar

It is the ratio of Insulation Resistance value of 1st
minute and 10th minute for any Electrical equipment.
Equipment is said to be sound if the ratio is greater than
one.

Is This Answer Correct ?    17 Yes 13 No

What is polarisation index value?.(pi value) Simple & brief definition of polarisation index?....

Answer / santhoshkumar

The ratio between IR value for 10 minutes to 1 minute.
It proves the healthiness of the insulation. Best value
will be above 1.2

Is This Answer Correct ?    7 Yes 4 No

What is polarisation index value?.(pi value) Simple & brief definition of polarisation index?....

Answer / rajpalsing rajput

It is the ratio of IR value at 10 min to the IR value at 1
min.It is measure of condition of insulation system wether
it is clean or dirty.If it is greater than 2 indicat the
good condition of insulation system and if it is greatore
than 6 indicate that insulation system is thermally degrade.

Is This Answer Correct ?    4 Yes 1 No

What is polarisation index value?.(pi value) Simple & brief definition of polarisation index?....

Answer / md. robiul islam

Polarization Index is an indicator which gives an idea of
the cleanliness of the windings. It is a ratio of the
Insulation Resistance Measured for 10 minutes to the
insulation resistance value measured after 1 minute. Since
it is a ratio; it does not have any units.

Polarization Ratio = Insulation Resistance after 10 minutes/
Insulation Resistance after 1 minute

The Polarization Index should be above 2.0 to be
permissible. Machines having PI below 2.0 cannot be operated.

Is This Answer Correct ?    1 Yes 0 No

What is polarisation index value?.(pi value) Simple & brief definition of polarisation index?....

Answer / karthikeyan

Polarisation intex test is used for find out the IR value at
a particular temperature

Is This Answer Correct ?    5 Yes 21 No

Post New Answer

More Electrical Engineering Interview Questions

can we apply kirchhoff's laws to circuits containing non linear elements?

3 Answers   Metro,


Does outdoor isolator loose connection cause short circuit current in that circuit? if yes then how ??

0 Answers  


bus bar design conditions and sizing pls tell me quickly

0 Answers  


What will be the current drawn by HT motor, if low voltage is applied.. any formula to calculate the LT amps of HT motor.?

0 Answers  


What is the need for a controller?

0 Answers  


What are the main problems in distribution? I have to do an assignment so which problem should I choose? Like power factor problem etc.

4 Answers  


why two contacts(in series) are using in closing circuit

3 Answers  


why is the transmission voltage is multiple of 11?

1 Answers   HAL,


In Aeroplane what circuitry or method use for earthing?

9 Answers   Bhel, EDA, Wind World,


What is non-minimum phase transfer function?

0 Answers  


why battery dc voltage become Half when we check with respect to ground for example 120volts + and - terminals and when we check + terminal with Earth thats 60volts why 60volts same result on 24Volts and with ground 12Volts only expert answer that thanks we can not ground the battery.

2 Answers   Etimaad,


what is the formula of starting current of 3phase and 1 phase motor???

0 Answers  


Categories
  • Civil Engineering Interview Questions Civil Engineering (5086)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4453)
  • Electrical Engineering Interview Questions Electrical Engineering (16638)
  • Electronics Communications Interview Questions Electronics Communications (3918)
  • Chemical Engineering Interview Questions Chemical Engineering (1095)
  • Aeronautical Engineering Interview Questions Aeronautical Engineering (239)
  • Bio Engineering Interview Questions Bio Engineering (96)
  • Metallurgy Interview Questions Metallurgy (361)
  • Industrial Engineering Interview Questions Industrial Engineering (259)
  • Instrumentation Interview Questions Instrumentation (3014)
  • Automobile Engineering Interview Questions Automobile Engineering (332)
  • Mechatronics Engineering Interview Questions Mechatronics Engineering (97)
  • Marine Engineering Interview Questions Marine Engineering (124)
  • Power Plant Engineering Interview Questions Power Plant Engineering (172)
  • Textile Engineering Interview Questions Textile Engineering (575)
  • Production Engineering Interview Questions Production Engineering (25)
  • Satellite Systems Engineering Interview Questions Satellite Systems Engineering (106)
  • Engineering AllOther Interview Questions Engineering AllOther (1379)