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.

how work the lighting arrestor?

2 Answers  

---

which cable is preferred PVC OR XLPE for voltage from 220V to 11 KV with proper justification

1 Answers   BARC, Sail,

---

what is meant by bus bar and outgoing/incoming breaker in an electrical/electronic circuit

3 Answers  

---

how much current capacity of 300 sq. mm cable (4 core aluminium) and 150 sq. mm cable ( 4 core aluminium)

3 Answers   Bhel, RR Kabel,

---

What are types of losses in the Transmisson Lines ?

4 Answers   GE,

---

how to introduce yourself

0 Answers  

---

How is efficiency of DG set calculated? At many places I found the efficiency to be mentioned in percentage. But at some other places I found kWH/ litres. I want to know how dimensionless percentage value is arrived at?

0 Answers   ADS Spirits,

---

We have .ht motor which is 60Hz.we run on 50Hz.so that it's speed reduce but we had one prob.that motor winding temp increase up to 135 deg.we want reduce this temp.what to do?we arrange ext.cooling fan but not much effect.we want reduce this temp. Inhouse without affecting much.cost. also don't want reWINDING OF MOTOR?

3 Answers  

---

WHAT IS THE FUNCTION OF PULSE TRANSFORMER IN DC DRIVE

5 Answers  

---

why some transformer without breather.

1 Answers   GTS,

---

Why earthing done?

1 Answers   CBRE,

---

Why is water motor not taking the pressure? what is the problem?

0 Answers  

---