Introduce:
CTX Series zero-sequence current transformers are used inconjunction with relay protection devices or signals when thepower system generates zero-sequence grounding current, sothat the device components can operate to achieve protectionor monitoring.
When an electric shock or leakage fault occurs in the circuit.the secondary side of the transformer outputs a zero-sequencecurrent, so that the equipment on the connected secondarv linewill be protected (cut off the power supply, alarm, etc.)
Mainfeatures:
- Epoxy resin casting encapsulation, good seismic resistance;
- Adoption of hole punching that is convenient for installation;
- Adoption of high permeability magnetic material, with wide measurement range;
- Elegant appearance, small volume, flexible using;
Application:
- Electric fire monitorin
- Fire prevention and leakage protection system
- Electromagnetic relaying protection
- Microcomputer protection, etc.
How does zero sequence current transformer work
The working principle of a zero sequence current transformer (ZCT) is based on the concept of magnetic induction. A ZCT is a type of current transformer that is used to measure the unbalanced current in a three-phase electrical system, which is also known as the zero sequence current or the neutral current.
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.
| Electrical parameters | Mechanical parameters | ||
| Frequency | 50~400Hz | Shell | ABS（flame retardant grade 94-V0） |
| Rated input | 10mA~5A | Bobbin | PBT |
| Measuring range | 10%In~130%In | iron core | Ni steel/nanocrystalline |
| Rated output | 0~1v (A or) 0~0.25mA | Internal structure | Environmentally friendly epoxy resin casting |
| Ratio difference | ≤±0.1% | Construction plan | Screw fixing |
| Phase difference | ≤±10 | Working temperature | -25℃~ +75℃ |
| Dielectric Strength | 2.5KV/1mA/1min | Ambient Humidity | ≤85% |
| Insulation resistance | DC500V/1000MΩ/min | Wiring method | Terminal type/shielded twisted wire 1.5m |
| Model Specifications | Dimensions | |||||||
| Reference current | A | B | C | D | E | F | G | |
| CTX-1025 | ≤100A | 155 | 63 | 105 | 30 | 148 | 5 | 28 |
| CTX-1432 | ≤225A | 205 | 75 | 145 | 35 | 198 | 5 | 28 |
| CTX-1832 | ≤400A | 245 | 75 | 184 | 35 | 238 | 5 | 28 |
| CTX-2245 | ≤630A | 295 | 95 | 229 | 50 | 288 | 5 | 28 |
| CTX-2645 | ≤1250A | 388 | 110 | 318 | 60 | 381 | 6 | 29 |
