Interested to Buy Any Domain ? << Click Here >> for more details...
What is polarisation index value?.(pi value)
Simple & brief definition of polarisation index?..
- 7 Answers
- 19011 Views
- I also Faced
- E-Mail Answers
Answer Posted / 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 |
Post New Answer View All Answers
why we testing the core balance of the transformer before comissioning?
What is making & breaking current ???
What is the function of RCBO? What are the different sensitivity ratings & each application?
What is Scheme Test of High Voltage Switchgear. Which tests it includes.
Hi.. I am a BE GRaduate in E&E. I have 8.5 Experience in Tendering & Estimation field. I have done SAP SD course few years back. But due to some reason i failed to get job in that field and continued my own field. Now I am thinking of changing into SAP seriously. How should i go ahead???
Dear all, I just want to ask an expert on this forum for some insights. For the magnetic balance test, when applied voltage on a Delta-Star transformer e.g. Dyn11, the following relationships apply for HV side: 1. H1-H2 = H2-H3 H3-H1 2. H2-H3 = H3-H1 H1-H2 3. H3-H1 = H1-H2 H2-H3 For the LV side also: 4. X1-X0 = X2-X0 X3-X0 5. X2-X0 = X3-X0 X1-X0 6. X3-X0 = X1-X0 X2-X0 Is there a similar pattern for Y-d, Y-Y, D-d? And how about Y-z, D-z, Z-y transformers? I've tested a YNzn5 transformer and for LV side I don't see the pattern. In this particular case I got for LV side the following (see values below): H1-H0 H2-H0 H3-H0 X0-X1 X0-X2 X0-X3 128.0 119.9 7.2 29.2 13.3 15.8 70.7 128.4 59.2 23.4 22.0 3.6 7.2 120.1 128.1 13.4 29.3 15.8 What is the relationship here for LV? For row 1 I see the relationship, for row 3 I also see but it's shifted, but for row 2 I don't see such relationship. Any suggestions, answers, someone?
How to address the servo drive for motor
how to fit 3 HP crompton gear motor with conveyor with the use of staring delta starter or ordinary starter?
A d.c. Shunt motor is found suitable to drive fans because they require?
How is operate breaker failure scheme in substation
What is the difference between relays and contactor construction wise?
why Y CONNECTION IS BETTER INTERMS OF EFFICIENCY AND P.F FOR A LAOD LESS THAN 40% AND WHY AFTER DELTA IS BETTER FOR > 40%
Why r u using pf panel. what the uses
how test transfomer(3 phase75kva) by megger
If the rated speed of a d.c. Shunt motor is1440 r.p.m, which method of speed control would you suggested to obtain a speed of 1500 r.p.m?
