Introduce:

The ZCT type zero-sequence current transformer is used in conjunction with the relay protection device or signal when the power system generates zero-sequence grounding current to make the device components act and realize protection or monitoring.

When an electric shock or leakage fault occurs in the circuit, the secondary side of the transformer outputs the zero-sequence current, so that the equipment on the connected secondary line can be protected (cut off the power supply, alarm, etc.).

Mainfeatures:

• Detection of unbalanced current: ZCT is designed to measure the unbalanced current in a three-phase electrical system, which is the sum of the three phase currents. This allows them to detect ground faults, which can occur when a fault current flows from one or more of the phase conductors to ground.
• High sensitivity: ZCT is highly sensitive and can detect even small amounts of ground fault current. This helps to prevent damage to equipment and reduce the risk of electric shock to personnel.
• Accuracy: ZCT is designed to provide accurate measurements of the zero-sequence component of the current, even in the presence of high levels of noise or interference.
• Non-intrusive installation: ZCT is typically installed around the neutral conductor of a three-phase system, which means that they can be installed without the need to break the circuit or interrupt power to the load.
• Frequency response: ZCT is designed to operate over a wide range of frequencies, typically from 50Hz to 400Hz, which makes them suitable for use in a variety of applications.
• Low burden: ZCT is designed to have a low burden, which means that they do not significantly affect the operation of the circuit or the accuracy of other measurement devices in the system.

Application:

• Electric fire monitorin
• Fire prevention and leakage protection system
• Electromagnetic relaying protection
• Microcomputer protection, etc.
  How does zero sequence current transformer work.The ZCT consists of a single primary winding and a secondary winding. The primary winding is connected in series with the neutral conductor of the three-phase system. When current flows through the primary winding, it generates a magnetic field around the conductor.

  The secondary winding of the ZCT is connected to a measuring instrument or a protection relay. When an unbalanced current flows through the primary winding, it creates a magnetic field that induces a voltage in the secondary winding.

  The voltage induced in the secondary winding is proportional to the unbalanced current flowing in the primary winding. The measuring instrument or protection relay uses this voltage to measure the unbalanced current or detect ground faults.

  The ZCT is designed to detect only the unbalanced current, which is the sum of the three phase currents. It is constructed in a way that it does not affect the normal operation of the three-phase system.

  Overall, the working principle of a zero sequence current transformer involves the induction of a voltage in the secondary winding of the transformer, which is proportional to the unbalanced current flowing in the primary winding. This allows the ZCT to detect ground faults and protect the electrical system from damage and personnel from electric shock.