Answer / amit shankar choudhary

Tan Delta, also called Loss Angle or Dissipation Factor
testing, is a diagnostic method of testing
cables to determine the quality of the cable insulation.
This is done to try to predict the
remaining life expectancy and in order to prioritize cable
replacement and/or injection. It is also
useful for determining what other tests may be worthwhile.
How Does It Work?
If the insulation of a cable is free from defects, like
water trees, electrical trees, moisture and air
pockets, etc., the cable approaches the properties of a
perfect capacitor. It is very similar to a
parallel plate capacitor with the conductor and the neutral
being the two plates separated by the
insulation material.
In a perfect capacitor, the voltage and current are phase
shifted 90 degrees and the current
through the insulation is capacitive. If there are
impurities in the insulation, like those mentioned
above, the resistance of the insulation decreases, resulting
in an increase in resistive current
through the insulation. It is no longer a perfect capacitor.
The current and voltage will no longer
be shifted 90 degrees. It will be something less than 90
degrees. The extent to which the phase
shift is less than 90 degrees is indicative of the level of
insulation contamination, hence
quality/reliability. This “Loss Angle” is measured and analyzed.

Answer / wareagle

Its tan delta. Not ten delta. You can google that for
yourself.

why we use star connection on the primary side of a transformer?

5 Answers   DRDO, TCE,

---

A 3-phase IM is supplied from 50 Hz system. It runs at speed of 1440 rpm and slip equal to 4 %. Calculate number of pole pairs. A 1 B 6 C 2 D 3

0 Answers  

---

what is the method of electric earth for the protection of low voltage electric equipment

1 Answers   MacLellan, Shiva Corporation, Siemens,

---

What is meant by load angle of an alternator? Upon what factors does the load angle depend?

0 Answers   VECL,

---

In separetly excited m/c,we excite the field by a dc source,what not with ac source?

2 Answers  

---

---

what are the duties of commutator in motor and generator?

6 Answers   L&T,

---

why overload relay is not tripped at time of starting of motor allthough staring current is too high?

5 Answers   TATA,

---

why there is a high voltage line in multiplication of 11?i.e.- -66kv,11,kv,22kv

4 Answers   Bhel,

---

where we use the SFU & FSU?

0 Answers   L&T,

---

why different series of vfds (like allenbradley)are used in industry ?

0 Answers  

---

The power dissipated by a resistor of 10ohm when a current of 2A passes through it is:(a) 0.4W(b) 20W(c) 40W(d) 200W

2 Answers  

---

PLZ EXPLAIN THE INTERLOCKING AND CONTROLLING OF CONTACTORS????HOW CAN I DO THAT?

2 Answers   Siemens, UPL,

---