TF1-25.50.100/1A

TF1-25.50.100/1A current transformer for aircraft AC systems

TF1-25.50.100/1A is an aircraft measuring current transformer used in onboard AC electrical systems. The unit converts higher primary current into a lower secondary measuring current suitable for aircraft ammeters and monitoring circuits. It is intended for safe current measurement in aircraft power lines, where full load current should not pass directly through the cockpit instrument. The transformer is part of the electrical measuring circuit, not a switching, protection or power conversion device.

Current scaling through TF1-25.50.100/1A

The transformer provides current scaling for several selectable primary current ranges. Depending on the connection of the input bus or conductor, the measuring circuit can be configured for different current limits. This allows one transformer type to be used in circuits where the required measured current range differs by installation point. The secondary circuit supplies the associated ammeter with a standardized measuring current, so the transformer and indicator must match by current ratio and aircraft wiring diagram.

TF1-25.50.100/1A with AF1 ammeters

The transformer is normally used with aircraft AC ammeters of the AF1 series. In this arrangement, the transformer reduces the measured AC load to a secondary value suitable for the instrument, while the ammeter displays the current in the selected circuit. The system is intended for aircraft AC networks with aviation frequency, including 400 Hz installations. If the indication is incorrect, the check should include the transformer, ammeter, secondary circuit, bus connection, wiring and connector condition.

Aircraft application of TF1-25.50.100/1A

TF1-25.50.100/1A is used in electrical systems of Mi-8 / Mi-17 / Mi-171 family helicopters and related aircraft configurations, depending on the installed equipment. It may be used in generator load monitoring, feeder current control or other AC measuring circuits. Exact applicability depends on the aircraft modification, electrical panel layout and ammeter type. Similar transformers can differ by current range, secondary current and frequency rating, so replacement should be confirmed through the aircraft electrical documentation.

Identification and ordering of TF1-25.50.100/1A

Before ordering, the full marking should be checked carefully, including all current range values and the secondary current designation. In Russian documentation, the unit may be written as ТФ1-25,50,100/1А, while in English requests it is usually written as TF1-25.50.100/1A. For correct selection, provide the aircraft type, electrical system application, associated ammeter, existing transformer marking and a photo of the unit if available.

Product Type: Aircraft measuring current transformer
Function: Conversion of high AC current into measuring current for aircraft ammeters
Application / Where Used: Aircraft onboard AC electrical systems
System / Installation Area: AC load monitoring and ammeter measuring circuits
Compatible Aircraft / Equipment: Mi-8 / Mi-17 / Mi-171 family helicopters, depending on configuration
Associated Instruments: AF1 series aircraft AC ammeters, including AF1-150 where applicable
Primary Current Ranges: 25 A, 50 A, 100 A
Rated Secondary Current: 1 A
Operating Frequency Range: 350–1200 Hz
Typical Aircraft Frequency: 400 Hz
Operating Temperature Range: −60 to +150 °C
Short-Time Housing Temperature Resistance: Up to +400 °C
Humidity Resistance: Up to 98% at +40 °C
Environmental Resistance: Designed for aircraft vibration loads
Alternative Designations: TF1-25.50.100/1A; TF1-25/50/100-1A; ТФ1-25,50,100/1А
Technical Documentation: Product passport and aircraft electrical system documentation available upon request

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Warranty
All products are covered by a standard 6-month warranty.
Extended warranty is available upon request and is agreed individually; it may affect the final product price.