Nice quality high permeability Permalloy core or aminated silicon
steel core Current transformer widely applied in electronic energy
meter, power transducer, RTU, etc
For our current transformers, which are produced by using high
permeability permalloy core or good quality laminated silicon steel
core, inflammable epoxy resin and case with our high precision
toroidal winding machine & current transformer testers, steady
quality and reliable safety, are widely applied in electronic
energy meter, power transducer, RTU, electronical monitoring meter,
power factor compensator, digital meter, motor control, industrial
control system, electrical meter equipment, etc.
Our precision current transformer's amplitude error and phase error
are tested by using high precision tester, elow is the tolerance
table:
| Accuracy | Primary current VS rated current percentage (%) | Tolerance | Secondary resistance VS rated resistance percentage (%) |
| phase error(%) | phase angle(') |
| 0.01 | 5 | ±0.02 | ±0.6 | 25~100 |
| 10~120 | ±0.01 | ±0.3 |
| 0.02 | 10~120 | ±0.04 | ±1.2 | 25~100 |
| 10~120 | ±0.02 | ±0.6 |
| 0.05 | 5 | ±0.1 | ±4 | 25~100 |
| 10~120 | ±0.05 | ±2 |
| 0.1 | 5 | ±0.4 | ±15 | 25~100 |
| 10 | ±0.25 | ±10 |
| 20 | ±0.2 | ±8 |
| 100~120 | ±0.1 | ±5 |
| 0.2 | 5 | ±0.75 | ±30 | 25~100 |
| 10 | ±0.5 | ±20 |
| 20 | ±0.35 | ±15 |
| 100~120 | ±0.2 | ±10 |
| 0.5 | 5 | ±1.5 | ±90 | 25~100 |
| 10 | ±1 | ±60 |
| 20 | ±0.75 | ±45 |
| 100~120 | ±0.5 | ±30 |
| 1 | 5 | ±3 | ±180 | 25~100 |
| 10 | ±2 | ±120 |
| 20 | ±1.5 | ±90 |
| 100~120 | ±1 | ±60 |
| 3 | 50~120 | ±3 | not sure | 50~100 |
CT05, CT07, CT10 are micro precise current transformer, which are
widely used in power transducers and electrical monitoring systems
and RTU, the typical application circuit refers to below drawing.
Based on rated primary current, an induced current will be created
in secondary; customers can adjust the resistance value in output
to get the required output voltage, and capacitor C and rheostat R
are used for compensation; if compensation is not required, and
capacitor and rheostat are no need to be connected. IC in below
drawing is a common operational amplifier; a better operational
amplifier can reach a higher precision and better stable function.
The accuracy of resistor R in below drawing is required to be less
than 1%, and temperature coefficient is less than 50PPM.
R=V0/10(KΩ), generally speaking, C is requested between
0.01~0.033uf, R is requested between 150KΩ~300KΩ (R, C can be
calculated by without compensated current transformer).
The second application is without operational amplifier in
secondary, refer to drawing (2), add a standard resistor RL in
secondary, then a linear output voltage can be got. A non-linearity
is less than 0.1%, once increased loaded resistance RL, a higher
output voltage can be got, linearity will not occur, so, it is
better not to choose a higher resistance value which is suggested
in this catalogue.
