In transmission lines there is a massive current, we use CT to make this current measurable i.e. it steps down the current but DT is used to step down the voltage
It's called a 'distribution transformer', as opposed to a 'power transformer' which is used in the transmission and primary-distribution electrical systems.
100MVA
Leakage reactance is useful for limiting the short circuit current in transformer and generators. therefore normally the reactance of transformer varies for 4.5% for distribution transformer to 12.5% for 400KV class.
A distribution transformer IS the term used to describe the utility transformer which supplies a residence.
I am assuming the question is about the power / distribution transformer and not the current transformer. The primary current is a function of load connected on secondary. With the open secondary, there is no load, no current, it is open circuit. Hence no primary current. However there is always some small amount of no load current in the primary winding.
it is depends on the rating of distribution transformer,e.g if there is 100 kva, then it will take 5.25amp.
The size of any switch depends on current it carries. Your statement is true for step down transformers. The primary is HV hence less current, so the tap changer is on primary side.
in welding machine, the transformer used is basically a current transforrmer. so by changing the tap of secondary side of transformer, we can increase or decrease the current in the transformer.
why does have to short-circuit secondary wire of current transformer ?
The maximum efficiency condition in distribution transformer is said to be occurred when iron loss = copper loss
7988052
in isolation transformer earthing is not provide on secondary side but in ordinary transformer neutral of secondary side is earthedAnswerAn isolation transformer is a 1:1 ratio transformer; its function is to electrically isolate the secondary side from the primary side without changing the voltage. An example of an isolation transformer is the one used in a shaver socket.A distribution transformer is a step-down transformer, used within the electricity network's distribution system. An example of distribution transformer is a pole-mounted transformer, supplying low voltage to residences.(Of course, all mutual transformers provide electrical isolation between primary and secondary.)