why we use REF and Differential Protection in one
transformers?my doubt is both protections are operated in
internal fault only.why we want to use 2 protections?please
clarify.
Answer Posted / ramji
The differential protection is used for protecting the
transformer from internal winding fault,internal winding
shorts etc.,.It operates through three sets of CT's
connected in and out of transformer.It may or may not
operate during minor earth faults.REF is used to detect the
earth fault at restricted zone where its protection CT is
connected.It will surely operate during earth fault.But not
in windings short.
| Is This Answer Correct ? | 31 Yes | 4 No |
Post New Answer View All Answers
i will applied in 1U-1W on 440 volt primary delta side. what is the result of magtic balance test
What is the classification of hydro projects based on installed capacity?
Why 15Amp. MCB is suitable to carry load of 1.5Ton Ac please Explain?
How to find out damper winding failure for synchronous machine?
How to operate a ac chilar plant?
what is arc flash and what are the hazards involved
What is the working principle of MIG welding? and its out put Voltage?
What range of speed can you get with the armature control method of speed control of d.c. Shunt motor?
What are the special cables required for explosion proof wiring?
What do you mean by turns ratio of instrument transformer?
in conventional fan regulators how the current varies with speed?
wat is meant by PX class in ct?
L.A. (Lightening Arrester) is located at a place from where transmission line enters the transmitting substation. So L.A. (Lightening Arrester) is the first equipments which has to encounter with lightening, high voltage surges and switching surges. It has to absorb energy of lightening, high voltage surges, and switching surges. L.A. (Lightening Arrester) is made up of layers of semiconductors. If these layers can not tolerate energy released by lightening, high voltage surges, and switching surges the L.A. (Lightening Arrester) blasts.
Explain what is rated speed?
In the formula : Knee point voltage = Burden X alf / class, Please inform what is alf? regards Shashidhar M.R.