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whats a core balance current transformer?
Core Balance CTs are special CTs used to detect Earth faults & usually used for Restricted Earth Fault Protection.
It is a ring type CT through which the cables carrying current of all the three phases (R,Y & B) are passed through. (In a 3phase 3 wire system)
Under normal operating conditions, summation of current through the three phases shall be equal to zero. In event of a fault, the summation of the current shall no longer remain zero (zero sequence current shall flow during earth fault) & thus the fault can be detected.
Wiki User
∙ 14y ago
Wiki User
∙ 12y agoIt is so called because the three phases acts as its core i.e. primary. It will not be energised as long as the current in the three phase system is under balanced condition. If there is an unbalance then there is a current flow in the secondary of the CT. This is used to energise the relay.
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V.LOGANATHAN
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What is use of metering core in transformer bushing?
It is the current transformer core meant for metering.
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 the meaning of magnetic balance test?
Magnetic balance test is performed on transformer to check, whether the core and windings of the transformer is balance position or not. Magnetic Balance is a test of Critical use as it helps us to enhance the efficiency and life of transformers.
Why are stripes of iron plates joined instead of using a single block of iron core in a transformer?
To reduce heat generated and eddy current losses in transformer's core during operation.
Core loss of an induction motor?
Just like a transformer, the core losses are a combination of eddy current losses and hysteresis losses.
What is use of metering core in transformer bushing?
It is the current transformer core meant for metering.
What is mean by magnetizing current of transformer?
A: As current flow in the primary it will magnetize the core of the iron in the transformer that is called magnetizing.
Why no load current in transformer small?
No load current is energizing current. This is effectively "lost" power, power used in the transformer to energize the core. It, therefore, should be small!
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 the meaning of magnetic balance test?
Magnetic balance test is performed on transformer to check, whether the core and windings of the transformer is balance position or not. Magnetic Balance is a test of Critical use as it helps us to enhance the efficiency and life of transformers.
What is the function of the primary current when the secondary winding of the transformer is open?
When the secondary of a transformer is opened, there is no longer any load on the transformer. There will be some current flowing in the primary winding, which is needed to induce the voltage in the secondary. This primary current is referred to as the "no load" current, and is indicative of the core losses in the transformer.
No load current of transformer is non sinusoidal even though sinusoidal voltage is provided in oc sc test?
eddy current loss in the transformer core is reduced by
Why the output voltage from a transformer is zero if a direct current flows through the primary coil?
A transformer relies on AC current flowing through the primary to set up changing magnetic fields in the core. The field flows through the core and in to the secondary of the transformer, generating an AC current. The current must be AC, otherwise the magnetic field in the core of the transformer will saturate. In the same way, the armature of a dynamo or alternator must be moving in order to create a changing magnetic field to create current through the windings.
What type of current must be used with a transformer?
DC current cannot be used in a transformer only AC will work. A transformer needs the continual build and collapse of the magnetic field to keep the iron core from reaching saturation. Only alternating current will transfer power through a transformer.
Why are stripes of iron plates joined instead of using a single block of iron core in a transformer?
To reduce heat generated and eddy current losses in transformer's core during operation.
What is the difference between ideal transformer and practical transformer?
There are basically 4 major differences :- 1. The windings (both primary and secondary) of an ideal transformer are considered to have zero resistance, hence the transformer is lossless. 2. There is no leakage flux in an ideal transformer. 3. The permiability of the core material in ideal transformer is considered to be tending to infinity and hence the current needed to set up the flux in the transformer is negligible. 4. There is zero hysterisis and eddy current losses in an ideal transformer.
Core loss of an induction motor?
Just like a transformer, the core losses are a combination of eddy current losses and hysteresis losses.
