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A current transformer is used in high voltage circuits where it is not possible to measure current directly. A CT is a step up transformer with only one turn in primary. There will be as many cores based on the purposes like metering, protection etc. The secondary of a CT should never be kept open circuited bcoz very high flux will be developed in the secondary and hence it may be damaged.
Wiki User
∙ 13y ago
Wiki User
∙ 8y agoA current transformer (CT) is used for measurement of alternating electric currents. Current Transformers, together with voltage (or potential) transformers (VT or PT), are known as instrument transformers. When current in a circuit is too high to apply directly to measuring instruments, a current transformer produces a reduced current accurately proportional to the current in the circuit, which can be conveniently connected to measuring and recording instruments. A current transformer isolates the measuring instruments from what may be very high voltage in the monitored circuit. Current transformers are commonly used in metering and protective relays in the electrical power industry.
Wiki User
∙ 12y agoA current transformer (CT) works just like any other transformer. It is important to note it is not referenced to ground. It reflects current flow, not phase to ground voltage, so it attempts to hold current constant, not voltage.
There is usually one primary "winding": one large cable through a donut CT, and multiple secondary windings. If a secondary winding is shorted (a wire placed across its terminals), the voltage built up in the secondary will be equivalent to V = I*Z, where I is the secondary current, and Z is the impedance of the secondary winding, usually specified as some flat value plus so many ohms per winding.
Wiki User
∙ 11y agoThe current transformer is used to measure the line current special transformer.
Direct measurement of the current large and small need to range from a few security until tens of thousands of security many ammeter. This gives the instrument manufacture a great deal of difficulty. In addition, some lines are high voltage, direct electricity meter to measure the current of the power lines on the road is extremely dangerous. The current transformer is used to solve these two problems of equipment.
The current transformer has two windings insulated from each other, set in a closed core column. At runtime, the primary winding and the measured line in series, the primary and secondary windings connected measuring instruments (eg, ammeter, power meter and power meter current coil, the low impedance of the relay coil, etc.). Therefore. Measuring the current of the power lines on the road, despite the transformer primary voltage is high, then face transformer secondary voltage is very low, the operator and instrumentation are safe.
Wiki User
∙ 10y agoA current transformer is an electrical device which is used to transform high current to a lower standardised current for control equipment used to messure current(amps)
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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 ac current is used in a transformer?
AC current or DC current can be used in transformers. A transformer is made of two coils of wire, the input coil induces a current into the output coil. Transformers change the voltage either up (step up transformer) or down (step down transformer). The amount of change in voltage is dependent solely on the number of windings in both coils in the transformer. DC transformers work exactly the same way AC transformers do.
Eddy current in transformer?
Yes, a transformer has eddy currents.
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.
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.
Which type of current does a transformer work with?
AC (alternating current)
Is power transformer is constant current device?
No, it has to be an alternating current in order to work
Is transformer work without freqency?
No. A transformer has to have AC, alternating current, to work. And since it's alternating, it'll have a frequency.
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.
How is current controlled in welding transformer?
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.
What is principle of Current transformer?
why does have to short-circuit secondary wire of current transformer ?
Difference between potential transformer and current trasnformer?
The difference between current transformer and potential transformer is that the secondary of a current transformer can not be open circuited while under service whereas that of the potential transformer an be open circuited without any damage to the transformer.
Why ac current is used in a transformer?
AC current or DC current can be used in transformers. A transformer is made of two coils of wire, the input coil induces a current into the output coil. Transformers change the voltage either up (step up transformer) or down (step down transformer). The amount of change in voltage is dependent solely on the number of windings in both coils in the transformer. DC transformers work exactly the same way AC transformers do.
Does led lighting require a transformer per light or one per circuit?
One transformer should feed several led's in parallel, but you have to work out how much current each one will take, total it up, and then get a transformer with the correct output voltage and that can supply the total current. Don't exceed the transformer max current or it may fail through overheating
Why you have to do current transformer knee point test?
we are not having anyother work, so only we are testing that.
What is zero current transformer?
It is a transformer with No load attach to it.
What is the reason for using a neutral current transformer on a transformer?
A current transformer is primarily used at the neutral point of a transformer for earth fault protection. A neutral current transformer will measure any ground fault current which will essentially flow from the star point of the transformer. A fault-detection device other devices is connected to the current transformer and, if the fault current exceeds a certain trigger value, the fault-detection device will give a trip command to an earth-fault relay to disconnect the supply of electricity to the transformer.
