Choosing the right current transformer isn’t just a technical decision—it directly affects system safety, accuracy, and long-term maintenance. With medium and high voltage systems increasingly adopting intelligent protection schemes, the demand for reliable CTs with precise performance has grown significantly.
Whether you're designing a substation panel, upgrading switchgear, or integrating a distribution transformer, the following factors should be carefully considered:
1. Rated Primary Current
Determine the maximum expected system load. Select a CT with a primary current rating slightly above the operating current to avoid saturation.
2. Burden and Accuracy Class
Burden (VA) refers to the load the CT drives. For protection circuits, an accuracy class like 5P10 is commonly used. For metering, 0.5 or 0.2 class is preferred.
3. Installation Location
Is it for indoor panel use, outdoor switchgear, or embedded inside a transformer tank? Choose resin-cast, oil-immersed, or dry-type accordingly.
4. CT Core Type
Single-core CTs are often used for protection; multi-core designs are chosen when both metering and protection are required simultaneously.
5. Standard Compliance
Ensure the product complies with IEC or ANSI standards based on your regional utility requirement.
Indoor switchgear: Compact epoxy-resin encapsulated CTs (6kV–36kV)
Pole-mounted transformers: Oil-immersed CTs for 11kV/33kV grids
Ring main units: Integrated CTs for smart protection relays
PUTAI Electric offers a wide portfolio of Current Transformers ranging from 3.6kV to 40.5kV. Whether for protection or metering, indoor epoxy cast or outdoor application, our CTs are designed to ensure stable accuracy over time and under fluctuating loads.
Our standard CT models are widely used in switchgear cabinets, RMUs, compact substations, and utility distribution systems across Southeast Asia, Africa, and Eastern Europe.
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