SPECIAL PURPOSE TRANSFORMERS
- POLY CARBONATE CT
- RELAY OPERATED CT
- AIR CIRCUIT BREAKERS CT
- CBCT
- SUMMATION CT
- CLASS PX CT's
POLY CARBONATE CURRENT TRANSFORMERS
![](https://preciseelectricals.com/wp-content/uploads/2022/11/10-1-1024x284-1.png)
- Poly carbonate is durable material
- High Impact resistance
- Low scratch resistance
- Usable in a wider temperature range
- Compact in size compared to resin cast CT’s
- Requires less cycle time compared to resin hence faster delivery.
RELAY OPERATED CURRENT TRANSFORMERS
![](https://preciseelectricals.com/wp-content/uploads/2022/11/8.png)
These are used in conjunction with contactors and motor control equipment. They provide accurate reliable against overload & single phasing.
AIR CIRCUIT BREAKERS CURRENT TRANSFORMERS
![](https://preciseelectricals.com/wp-content/uploads/2022/11/7.png)
Air Circuit Breakers are used right upto 6000A. For thermal & thermo magnetic protection CT is integral part. CTs are available in various insulation forms such as castings, thermoplastic & tape insulated.
CBCT
![](https://preciseelectricals.com/wp-content/uploads/2022/11/CBCT.png)
- Used for earth fault protection in grounded three phase systems
- All the three phases are made to pass through the CT inner window
SUMMATION CT
![](https://preciseelectricals.com/wp-content/uploads/2022/11/Summation-CT.png)
- Consist of two or more primary windings which are connected to the feeders to be assumed.
- A single secondary winding, which feeds a current proportional to the summed primary current.
CLASS PX CT's
![](https://preciseelectricals.com/wp-content/uploads/2022/11/Class-PX-CTs.png)
- In balance systems of protection, CT’s with a high degree of similarity in their characteristics is required. These requirements are met by class PS (PX) CT’s.
- Their performance is defined in terms of a knee-point voltage (vk). the magnetizing current (imag) at the knee point voltage or 1/2, 1/4 the knee-point voltage, and the resistance of the CT secondary winding corrected to 75℃ (Rct)