Internal Fault means, fault due to winding, insulation, core etc which are inner side of transformer.
External fault means, Fault due to atmosphere Condition where transformer is placed moisture,dust, etc
Internal and external
Transformer Bushings are specially designed electrical terminals for taking out winding ends (leads) through the openings provided on the top cover or wall of the of transformer tank and connecting to the incoming and outgoing lines.cravi@gmail.com
external sexual
jugular veins...internal and external
The common cartoid arteries divide to form the internal cartoids and external cartoids. The external cartoids carry blood to the neck and the outside of the skull. The internal cartoids enters the skull to deliver blood to the brain.
if we are seeking for internal protection of transformer only, then if any external fault occurs then it will show the fault though it should not. what a percentage differential protection will do means, it will include a restraining coil which is excited by the current in the transformer itself. Also the percentage differential relay ha taps. So it is easy to avoid the external fault. for reference check 'theory and applications of transformer differential protection' by GEORGE W.McKENNA, AIEE transactions 1950,volume 69
The current input (primary) to a transformer is proportional to the output (secondary) current. Differential protection relays monitor these via current transformers (CT). The percentage of difference between primary and secondary can be adjusted. If it is over the seting the relay will trip the primaryand secondary feeder breakers. Thus indicating an inbalance between internal phasewindings and or shorts to earth.
I am going to assume that you are asking about a differential relay. It is basically just that- it compare two different sources and will trip at a set value value of the difference. These can be directional as well. A couple of examples are transformer protective relays and bus differential. A transformer relay will measure the amount of current coming into the transformer and the amount of current going out. If there is a disparity due to an internal fault the relay will trip the supply source and deenergize the transformer. Same for the Bus differential.
Supply transformers at substations are provided with circuit-breakers for protection.
internal external not internal external not
its internal
It enforced internal peace and security, external protection, and promoted prosperity.
Is a salmon internal or external?
External
What is internal and external sources?
internal
external