The high accuracy current transformer (CT), which has very low phase error (phase shift) and ratio error (current error) for measurement, usually has a good linearity core inside and a winding coil with a large number turns. Although 0.1 class CT is most popular, we can also provide current transformers of 0.05 class stipulated by the Chinese National Standard, which have phase error of 4′ when input is 5% of rated current, or even higher accuracy class. When DC offsets exist in the circuit, it’s better to choose our DC immune type current transformers, which are made of amorphous & nanocrystalline composite cores.
Plastic case with epoxy resin fixing is the most common type of encapsulation for our high accuracy CT, as it provide good protection for the coil. Insulation tape wrapped CT has the advantage of flexible for pilot production, as no plastic mold is required. Due to the sophisicated winding technology and high grade CT cores we made ourselves, we can provide compact size toroidal current transformers with excellent linear output, high sensitivity and low measurement error. For high precision industry electricity meter, our heavy current type CT with big through-hole is more suitable. We can also manufacture customized current transformer for clients’ special requirements.
High Accuracy Current Transformer
Features
- A variety of encapsulations, with or without DC immunity
- Plastic box with epoxy resin vacuum potting, or double insulation wrapped
- Through hole or busbar type, easy to fix and install
- High linearity over the whole current range
- Accuracy up to 0.05 class, low phase error
- Meet the standard IEC 60044-3, JB/T10665
- Customized current transformer available
- Quick prototype development and sampling
Applications
- Energy meters, smart meters
- Electrical measuring instruments
- Electrical protective devices
- Current sensing modules
- Electronic power meter
- E-Mobility charging station
- Current measuring
- Ammeter
- Unbalance current
- Converter
- Smart grid
- Power supply
- Instrument component
Ratio Error and Phase Error
Ratio error (or current error) ±(%) in the following currents.
| Accuracy Class | 0.01In | ≥0.05In |
|---|---|---|
| 0.05 | 0.1 | 0.05 |
| 0.1 | 0.2 | 0.1 |
| 0.2 | 0.4 | 0.2 |
| 0.5 | 1.0 | 0.5 |
Phase error(′) In the following currents. Note: When current is 0.2In~Imax, phase error(δe ) is the average of δmax and δmin; When current is i, the phase error of i is the difference of betweenδi and δe. (△δi=δi-δe)
| Accuracy Class | 0.01In | 0.05In | 0.2In | In | 2In | 3In | Imax |
|---|---|---|---|---|---|---|---|
| 0.05 | 8 | 4 | 2 | 2 | 2 | 2 | 2 |
| 0.1 | 15 | 8 | 5 | 5 | 5 | 5 | 5 |
| 0.2 | 30 | 15 | 10 | 10 | 10 | 10 | 10 |
| 0.5 | 90 | 45 | 33 | 30 | 30 | 30 | 30 |
Basic Parameters
| Description | High Accuracy Current Transformer |
| Structure Of Winding | Toroidal |
| Phase | Single, Three |
| Input / Output | 10~600A/1~40mA |
| Max. Current | 10~600 A |
| Turns Ratio | 1:1000~25000 |
| Burden (Rb) | 5~100 Ω |
| Accuracy Class | 0.05/0.1/0.2 Class |
| Core Inside | DC Immune Dual Core |
| Encapsulation | Plastic Case, Double Insulation |
| Busbar Type | None |
| Mounting Method | Screw Fixing, Through Hole |
| Application | Meters, Instruments |
| Accept Customized | Yes |
Specifications
| Model (Part Number) | Input/Output | Current Rating(A) | Turns Ratio | ID(Hole) (mm) | OD(Dist.) (mm) | HT (mm) |
|---|---|---|---|---|---|---|
| MS12-10A | 12A/12mA | 12 | 1:1000 | Φ13 | Φ30 | 17 |
| DT20-10B | 2.5(20)A/2mA | 20 | 1:1000 | Φ5.5 | Φ17.5 | 14 |
| DT20-10A | 2.5(20)A/2mA | 20 | 1:1250 | Φ5.5 | Φ17.5 | 14 |
| DF40-25E | 5(40)A/2mA | 40 | 1:2500 | Φ8.5 | Φ26 | 17.2 |
| DF120-25B | 15(120)A/6mA | 120 | 1:2500 | Φ13 | Φ37.5 | 14 |
| DF120-25C | 15(120)A/6mA | 120 | 1:2500 | Φ13 | Φ37.5 | 14 |
| DS200-50A | 20(200)A/4mA | 200 | 1:5000 | Φ41 | Φ68 | 22 |
| DT200-50A | 20(200)A/5mA | 200 | 1:5000 | Φ42 | Φ72 | 24.5 |
| DT200-50B | 20(200)A/5mA | 200 | 1:5000 | Φ43 | Φ68.5 | 22 |
| DT400-100B | 400A/40mA | 400 | 1:10000 | Φ27 | Φ61 | 32 |
| DT400-250B | 400A/16mA | 400 | 1:25000 | Φ27 | Φ61 | 32 |
| MT400-50A | 400A/40mA | 400 | 1:5000 | Φ23 | Φ59.5 | 21.4 |
| D-2A | 10~600A/1~40mA | 10~600 | 1:1000~25000 | Φ3~80 | Φ10~100 | 6~50 |
| D-2B | 10~600A/1~40mA | 10~600 | 1:1000~25000 | Φ3~80 | Φ10~100 | 6~50 |
| D-2C | 10~600A/1~40mA | 10~600 | 1:1000~25000 | Φ3~80 | Φ10~100 | 6~50 |
| D-2D | 10~600A/1~40mA | 10~600 | 1:1000~25000 | Φ3~80 | Φ10~100 | 6~50 |
Note:
The above data are selected from some popular models we produce. Please contact us for detail datasheet. We can also design some special high accuracy current transformers to meet customers’ requirements.