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A fault causing a difference between the primary and secondary currents of a power transformer. Usually a leakage to earth from somewhere in a winding. Such errors are caught by a protective circuit comprising two current Transformers for transformation of the primary and secondary currents respectively, in a common scale typically 0...1 or 0...5 A and bringing them together in a loop. A transverse branch in the middle of the loop collects the differential current set up in case of a fault, the so called 'spill' current. The differential branch uses this current to operate the operating winding of the protection relay and through this the alarm and trip contacts. The protection circuit thus simulates what is happening in the power circuit in an under graded and more direct issue.
Wiki User
∙ 13y ago
Wiki User
∙ 11y agoTransformer is device which is coverting the high voltage in to the low voltage , the main losses in transformer are cu loss,individul windings of the transformer short circuit, some times oil can leakage that shoulde causes transformer efficency can not maintain the certain value. The major loss present in the transformer is the some times neutral can act as a un grounded neutral that means there is no earthing connector
Wiki User
∙ 6y agoIt is known that the value of transformation ratio (actual ratio) is not equal to the turns ratio in current transformers. Also the value is not constant, but depends upon the magnetizing and loss components of the exciting current, the secondary winding load current and its power factor. This means that the secondary winding current is not a constant fraction of the primary winding current but depends upon the factors listed above.
Wiki User
∙ 15y agoOver current ( or overload) , short circuit and ground fault. Also there is possibility of overvoltage due to shifting of neutral if it is with ungrounded neutral.
Wiki User
∙ 12y agoInter-turn short circuits in individual windings.
Wiki User
∙ 13y agoOpen or shorted windings.
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What is the reason to use open circuit and short circuit methods to find Transformer losses?
The transformer can be tested on open and short circuit to find the iron losses and copper losses separately, which uses a fraction of the power than having to run the transformer on full-load.
What is short circuit voltage?
Short circuit voltage is the voltage that has to be applied to the primaries of a transformer, so that the nominal current flows through the secondaries, when they are shorted. This value is important, if transformer secondaries shall be used in parallel. Ideally all transformers with parallel secondaries should have the same short circuit voltage. When their short circuit voltages are different, the transformer with the lower short circuit voltage will be loaded more than their relationship of power ratings would predict. The short circuit voltage is also important in the design of a transformer, because it predicts, how much the secondary voltage will drop at nominal output current. This knowledge helps the designer to find out, how many further windings the secondary needs for a certain voltage in relation to an ideal transformer. Short circuit voltage is also known as impedance voltage.
Why the open and short ckt test of transformer is needed?
The open/short-circuit test on a transformer isn't 'needed'. It's only used if you want to find out the efficiency of a transformer.
How current transformer get burn when open circuit happens?
Because of fire
Why does a phase in secondary side in distribution transformer give low voltage?
transformer is busted; if input voltage is normal you have short circuit or open circuit somewhere
When the transformer is connected to the power source the secondary current is 0 what is the possible fault in the transformer?
A secondary current of 0 would suggest to me that the secondary circuit is open. A normally operating circuit with zero current flow would be very unusual. No load in secondary circuit. No secondary current can also be attributed to the primary power source open or an open primary winding.
How will be conduct test on transformer?
Short circuit test and open circuit test are widely used to test the efficiency of the transformer.
What is difference between isolation transformer and earth protection relay?
An isolation transformer is a mutual transformer having a voltage ratio of 1:1, so that the secondary circuit is electrically isolated from the primary circuit, yet subject to the same voltage.An earth protection relay is a category of protective relay that responds to an earth fault monitored by a current transformer (CT). In the event of an earth fault being detected by the CT, the relay with activate the trip circuit to a circuit breaker which will then disconnect the fault.
What is the reason to use open circuit and short circuit methods to find Transformer losses?
The transformer can be tested on open and short circuit to find the iron losses and copper losses separately, which uses a fraction of the power than having to run the transformer on full-load.
What is short circuit voltage?
Short circuit voltage is the voltage that has to be applied to the primaries of a transformer, so that the nominal current flows through the secondaries, when they are shorted. This value is important, if transformer secondaries shall be used in parallel. Ideally all transformers with parallel secondaries should have the same short circuit voltage. When their short circuit voltages are different, the transformer with the lower short circuit voltage will be loaded more than their relationship of power ratings would predict. The short circuit voltage is also important in the design of a transformer, because it predicts, how much the secondary voltage will drop at nominal output current. This knowledge helps the designer to find out, how many further windings the secondary needs for a certain voltage in relation to an ideal transformer. Short circuit voltage is also known as impedance voltage.
How transformer conduct current through ground?
A transformer doesn't 'conduct current through the ground'. However, in the event of a ground fault in the circuit supplied by a grounded transformer, the resulting fault current will flow through the earth back to the grounded terminal of that transformer's secondary winding.
Why the open and short ckt test of transformer is needed?
The open/short-circuit test on a transformer isn't 'needed'. It's only used if you want to find out the efficiency of a transformer.
How current transformer get burn when open circuit happens?
Because of fire
Why does a phase in secondary side in distribution transformer give low voltage?
transformer is busted; if input voltage is normal you have short circuit or open circuit somewhere
Function of no-load in transformer in a open-circuit?
To calculate the no load current from transformer & core loss is also calculated.
What is open on fault?
There are isolation devices (Circuit breakers) meant to cut off or OPEN automatically when a fault occurs. The breaker has "opened" on fault.
How do you carry open circuit test on power transformer?
A Linear power transformer coil? use an Ohm meter and check the resistance of the coils. No resistance is an open circuit. Also check for a cross circuit from one side of the transformer to the other.
