🔍
Request Answer
What is the Polarization index value? (Pi value) and simple definition of polarization index? 
0 like 0 dislike

Please log in or register to answer this question.

1 Answer

Its ratio between insulation resistance (IR) i.e. meggar value for 10min to insulation resistance for 1 min. It ranges from 5-7 for new motors & normally for motor to be in good condition it should be Greater than 2.5. 

Polarization Index Test (PI) – The PI test measures the ability of the insulation to absorb voltage over a period of time. This gives an indication of the overall insulation quality of the individual pieces of insulation in the transformer. This test is usually performed in conjunction with the Meggar Test. It is measured as ratio of insulation resistance (IR) for 10 minutes to insulation resistance for 1 minute.
0 like 0 dislike
Next Question ⇨⇦ Previous Question

Related questions

Why we do 2 types of earthing on transformer (i.e. :) body earthing & neutral earthing, what is function. i am going to install a 5oo kva transformer & 380 kva DG set what should the earthing value?
Last Answer : The two types of earthing are Familiar as Equipment earthing and system earthing. In Equipment earthing: body (non-conducting part) of the equipment should be earthed to safeguard the human ... earthing will be further classified into directly earthed, Impedance earthing, resistive (NGRs) earthing....

Show More
0 like 0 dislike
1 answer

Random Images

What is the effect of capacitance of a PN junction diode as forward and reverse bias are applied?
Last Answer : In a p-n junction diode, two types of capacitance take place. They are,  Transition capacitance (CT)  Diffusion capacitance (CD) 1. Transition capacitance (CT)  We ... in number of minority carriers stored outside the depletion region  dV = Change in voltage applied across diode ...

Show More
0 like 0 dislike
1 answer

Random Images

What is Boucholz relay and the significance of it in to the transformer? 
Last Answer : Boucholz relay is a device which is used for the protection of transformer from its internal faults, it is a gas based relay. whenever any internal fault occurs in a transformer, the Boucholz ... circuit then it stop its sound itself otherwise it trips the circuit by its own tripping mechanism....

Show More
0 like 0 dislike
1 answer

Random Images

The peak value of a sine wave is 200 V. Its average value is a. Square wave b. Half wave rectified sine wave c. Triangular wave d. Sine wave
Last Answer : Ans. a. Square wave...

Show More
0 like 0 dislike
1 answer

Random Images

The peak value of a sine wave is 200 V. Its average value is a. 127.4v b. 141.4v c. 282.8v d. 200v
Last Answer : Ans. a. 127.4v    ...

Show More
0 like 0 dislike
1 answer

Random Images
...