moct is device measure the current by means of faraday's effect..
CT(Current Transformer) is used to measure current flowing in the circuit. Current can be fully drawn or sensed in series condition. That's why , it is connected in series. In parallel , the current is divided; and hence the total current cannot be measured)
A power transformer is used to provide power (to your home, for example), an instrument transformer is used to measure voltage or current (for metering, for example).
This is the current level needed to energize a transformer to its rated voltageThe clue is in the name! 'Excitation' means to create a magnetic field. So the excitation current is the current drawn from the supply which sets up the magnetic field around the core.
Primary winding carry more current. We measure the current in one single wire, so no of turns are 1, in secondary the no of turns are higher. so, obviously it has higher voltage then this wire. so, finally as per the transformer rule the secondary carry lesser current than primary.
connect 3 - phase supply to transformer primary winding.....keep transformer secondary winding open..... apply 3-phase voltage i.e.400v ac, and measure the amount of current flowing in each phase of the transformer primary winding...this current is the transformer magnetising current..... we can keep multimeters in series with the source....so we can measure directly the current readings.....(keep multimeters in current mode, and generally magnetising current will come in terms of milli amps for 400 v )
moct is device measure the current by means of faraday's effect..
Current transformer is a device used to measure the flow of current through a power system and the measured current is inputted to a protective relay system. It is used to detect system malfunction. Current transducer is a device used to measure AC and DC current based on the halt-effect technology.
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.
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.
Current Transformer- Instrument transformer used for measure high current. it hasless and thin turns in primary and more and thick turns in secondary.Potential transformer- Instrument transformer used for measure high voltage. it has more and thin turns in primary and less and thick turns in secondary.CommentUnfortunately, the original answer has got things the wrong way around for the CT! A current transformer's primary has a thicker conductor than its secondary.
CT(Current Transformer) is used to measure current flowing in the circuit. Current can be fully drawn or sensed in series condition. That's why , it is connected in series. In parallel , the current is divided; and hence the total current cannot be measured)
Measure the current and voltage on the secondary side.
A power transformer is used to provide power (to your home, for example), an instrument transformer is used to measure voltage or current (for metering, for example).
A current transformer doesn't 'measure current'. It merely reduces a large current flowing through its primary to a smaller current which can be read by an ammeter connected to its secondary. At the same time, it electrically isolates the secondary circuit from the primary circuit, which is essential if the primary circuit is part of a high-voltage system.
the capacity of a transformer is defined as a product of voltage and current flowing through it.AS THE CURRENT IS MEASURED IN AMPERES AND VOLTAGE IN VOLTS, Hence transformers are measured/rated in KVA
You cannot measure DC current with a transformer. You can only measure AC current with a transformer.Another AnswerPower grids are generally a.c. systems, with d.c. being reserved for either very long-distance transmission lines, undersea cables, or as links between independent a.c. grids. to measure the currents in high-voltage a.c. lines, a current transformer's primary is inserted into the line, and its secondary reduces the value of that current to safe values for measurement and, very importantly, isolates the user from the h.v. system.