Interested to Buy Any Domain ? << Click Here >> for more details...
1)Why electric shock is feel ?? n in a Electric Train why
we didnt feel that ?
2)What is the reason for transformer Noise ??
3)What is relation b/w Transmission Lines & Communication
Lines ?
4)Which material is used for making Transformer oil & How u
measure its dielectric strength & Name the test ?
- 14 Answers
- 27386 Views
- NTPC, Tata Power, I also Faced
- E-Mail Answers
Answer Posted / rajkumarsripelli
ya....this is rajkumarsripelli Testing engineer trasformer
division...
4ans: The dielectric strengh can be caluculated by oil
insulation breakdown test by using an equipment called as
oil insulation breakdown kit..in this kit will be having
two electrodes seperated by small distance in a small glass
tank.in that small tank we will be filling the oil to
test . by applying the required voltages like 10kv or
20kv ,30kv....(this voltages depends on tha transformer
ratings)between the electrodes we can see the results..
for example suppose we have oil of unknownbreak downvalue
(suppose 50KV)
. To test this oil we have to fill this oil into kit(tank)
and voltage will applied between the electrodes..from 0v to
60kv..so here the voltage will be increased slowly...if the
voltage reaches 49kv inside the tank we will not find any
flash over between the electrodes but when it reaches 50kv
the flash over will be taken between the two
electrodes...so by this test we can conform that given oil
is having breakdown value at 50kv...so this oil will be
used in transformers which are opearated with 33kv
voltages that means oil insulation breakdown value should
be double as compared to its normal operating volages...
thank u....
| Is This Answer Correct ? | 22 Yes | 2 No |
Post New Answer View All Answers
what is the interrelation between voltage current torgue speed and magnetic flux in case of different types of electric motors
what is a types of short circuit and what is a types of distance protection tests
Can you explain about pole discrepancy scheme
Generator,motor and alternator Working principal Please explain easily
In AC if the direction of current keeps reversing every half cycle, how does it propogate through the transmission lines?
what is meant by brushed alternator & its working principle ?
what is star delta starter? how it works? give its control and power diagram.
What is Traction? 1KVA Alternator, How much urrent taken?
1. What is differential relay? How it operates? 2.How to calculate the Short Circuit Impedance in Transformer? 3.What is the alternate solution for testing of polarity by using polarity tester while its milli ammeter does not works? 4. While testing the 33KV Busbar by using Hipot kit, what should be the test voltage we have to apply? 5. What is the procedure/activities to be taken to inject the current more than 2000A by using 2000A Loading Transformer? 6. Explain how you can give the overload setting to any Motor Protection Relay for a HT motors with formula and example? 7. Why restricted earth fault protection is needed? Why can’t differential Protection is sufficient? 8. What should be the minimum and maximum ohmic value for earthing? 9. Why DC Currents are not used in transformer? 10. What is the Frequency while we step up the voltage from 220V to 11KV? Is it possible? Explain it?
why would the rotor rotate at sub synchronous speed against the direction of rotating flux when d rotor of 3 phase IM is connected to 3 phase balanced supply and the stator windings are shortcircuited ??
we have an energy meter in a capacitor bank panel, So should we consider it's readings as energy consumption on daily basis. (when capacitor bank doesn't have any energy losses)
what is the difference between neutral and earth
what kvrah y we need to take the readind of that
How would you calculate power loss in a resistor?
Diagram and details of polarity test for Current Transformer 11kv 400/200/100/1A
