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FZ transformer manufacturer .jpg

FZ Series Current Transformer: Reliable Power System Solutions from China Suppliers and Factory

A current transformer (CT) is a crucial component in electrical systems for managing, monitoring, and safeguarding power infrastructure. This device excels in transforming large alternating currents (AC) into small, precise measurements, making it indispensable for power generation, transmission, distribution, and industrial applications. By utilizing advanced technology, our current transformers ensure reliable connections between high-current power circuits and safety relays or sensitive measuring instruments. As a leading supplier and factory in China, we are committed to providing high-quality current transformers tailored to meet various industry needs. Trust us for efficient and effective solutions in electrical equipment
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    Product Details

    Product Overview

    A CT uses electromagnetic induction and contains two windings: a primary winding with a few turns connected in series to the high-current circuit, and a secondary winding with numerous turns connected to safety or measurement devices. The primary winding receives a large current, but the secondary winding, which is typically tuned to 5A or 1A for most industrial applications, receives very little current. This proportionality, also known as the transformation ratio, enables precise current monitoring while protecting personnel and equipment from potentially harmful voltages.

    Linearity Reduces measurement error for reliable readings.
    High Precision Essential for accurate energy metering.
    Sufficient Insulation Maintains high voltage separation between windings.
    ⚠ Important Safety Warning: Never leave the secondary winding open circuit when using a CT. An open circuit may produce extremely high voltages, which can damage electrical equipment and endanger personnel.

    Current transformers are essential to guaranteeing the dependability, effectiveness, and safety of contemporary electrical systems since they allow for more accurate current monitoring and enhanced problem identification.

    Technical Parameters

    Type Main Loop Current (mm) Outline Size
    A B C D E F G H M
    FZ-1025 ﹤ 100A 175 75 37 36 100 25 150 18 c4*10
    FZ-1435 < 250A 216 87 37 36 140 35 .5 18 c4*10
    FZ-1835 < 400A 256 87 37 36 180 35 .5 18 c4*10
    FZ-2245 < 630A 62311 100 37 36 220 45 286 18 c4*10
    Rated Primary Current: IA Second Current: 0.5mA

    All dimensions are in millimeters (mm). Scroll horizontally on mobile to view full table.

    Frequently Asked Questions

    1 What is a Current Transformer (CT) and how does it work?
    A Current Transformer (CT) uses electromagnetic induction to step down high currents to a safer, measurable level. It has two windings: a primary winding connected in series to the high-current circuit and a secondary winding connected to measuring or protection devices. The ratio between primary and secondary currents is known as the transformation ratio.
    2 What are the standard secondary output currents for industrial CTs?
    For most industrial applications, the secondary winding of a CT is typically rated at either 5A or 1A. These standardized output levels allow compatibility with a wide range of measurement and protection instruments used in industrial environments.
    3 Why should the secondary winding of a CT never be left open circuit?
    Leaving the secondary winding open circuit is extremely dangerous. Without a connected load, the CT can generate extremely high voltages across the secondary terminals, which may damage the transformer, connected equipment, and pose a serious safety hazard to personnel. Always ensure the secondary is connected to a rated burden before energizing.
    4 What are the key performance requirements for a current transformer?
    The three main performance requirements for a CT are: Linearity — to minimize measurement error across the operating range; High Precision — especially important for energy metering applications; and Sufficient Insulation — to maintain safe voltage isolation between the primary and secondary windings.
    5 Which CT model is suitable for currents up to 400A?
    The FZ-1835 model is designed for main loop currents of less than 400A. It has an outline size of 256mm (A) × 87mm (B) and is suitable for medium-load industrial applications requiring accurate current measurement and protection.
    6 What role do current transformers play in modern electrical systems?
    Current transformers are critical components in modern electrical systems. They enable accurate current monitoring, protect personnel and equipment from high voltages, support energy metering, and enhance fault detection capabilities — all of which contribute to the overall reliability, efficiency, and safety of electrical infrastructure.