PO-750A-2S
Rotary Converter
Description
Aircraft rotary converter PO-750A-2S
The PO-750A-2S is an aircraft single-phase electromechanical rotary converter. It converts DC power from the onboard electrical system into AC power for equipment that requires a 115 V / 400 Hz supply. This type of unit is used on Soviet and Ukrainian aircraft as a normal, standby, or emergency power source for radio, navigation, and instrument equipment. It is not a static inverter. The unit has a rotating motor-generator layout, so mechanical condition matters as much as the electrical output.
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Power supply function of PO-750A-2S
In operation, the PO-750A-2S receives 27 V DC from the aircraft power system. The DC motor drives the single-phase synchronous generator mounted on the same shaft. The generator then supplies sinusoidal AC power to connected consumers. This arrangement is common on aircraft where part of the avionics and navigation equipment needs stable 400 Hz AC power, while the main onboard network is based on DC power. During inspection, output voltage, frequency, load current, starting current, brush condition, and bearing condition should be checked together.
PO-750A-2S in radio and navigation equipment circuits
The converter can supply radio communication equipment, navigation blocks, instrument circuits, and other onboard consumers that require single-phase AC power. It is used on aircraft and helicopters such as An-24, An-26, Mi-8, and Mi-26, depending on the aircraft configuration. On some platforms it may be installed as a main converter, while on others it works as a reserve or emergency source. The exact role must be confirmed from the aircraft electrical diagram, because similar converters can be wired into different buses.
Construction of the PO-750A-2S converter
The PO-750A-2S combines a DC motor and a single-phase synchronous generator in one housing. Both machines are arranged on a common shaft. A separate box with starting and regulating equipment is mounted on the body of the unit. This equipment stabilizes rotational speed and output voltage. Electrical contact in the collector assembly is provided by aviation electrocarbon brushes, including MGS-8 type brushes used for this class of rotary converter. Brush size and grade should be checked against the repair manual before replacement.
Identification and ordering of PO-750A-2S
Before ordering, the marking on the data plate should be compared with the aircraft parts catalog or electrical equipment list. PO-series converters include several models with different output power, current ratings, and installation layouts. A converter removed from one aircraft may not be a direct match for another without checking mounting points, wiring, and connected loads. For correct selection, it is useful to provide the aircraft type, installed converter marking, required output power, and a photo of the nameplate. The product is also known under alternative designations PO-750A-2S, PO-750A 2S, and ПО-750А-2С.
PO-750A-2S: identification and purpose
PO-750A-2S is classified as a Rotary Converter and converts aircraft electrical power through an electromechanical motor-generator assembly. Select it by the complete designation, series, execution, marking and approved documentation. Similar lettering, housing or connector geometry does not establish identical operating data.
This historical category contains several types of transducing devices. PT, PO and PTS products relate to electrical-power conversion, while PMI, PMT and PMM designations identify vacuum-gauge transducers. Each page therefore follows the actual product function rather than the broad category name. A suffix, series number or extra letter can indicate a materially different circuit, pressure range, rating or interface.
Function and operating circuit
The item converts aircraft electrical power through an electromechanical motor-generator assembly. Exact input and output conditions depend on the execution. For a power converter, verify voltage, current type, frequency, phase arrangement, rated output, connectors and cooling. For a vacuum transducer, verify the measurement principle, pressure range, operating mode, vacuum connection and compatible measuring instrument.
Numerical values retained from the original catalogue record appear in Technical Details and must be compared with the passport for the actual unit. An aircraft platform or installation system is not assigned by analogy when a reliable source is unavailable.
Selection and compatibility checks
Before replacement, compare the primary and alternative designations, series, input and output ratings, dimensions, mass, connectors, mounting, cooling and documented environmental limits. For a vacuum sensor, additionally compare the conversion constant, emission current or heater resistance where the passport specifies those values.
Related members of one family may use different voltage, frequency, power, pressure range, mounting interface or purpose. The related links below support catalogue navigation and do not establish interchangeability. General technical background is available under Rotary Converter.
Incoming inspection and installation
Check the marking and supporting records, housing, connectors, terminals, vacuum fitting, mounting points, seals and any evidence of overheating, impact or corrosion as applicable. Bench testing must follow the documentation for the exact execution; an improvised test voltage or vacuum regime can damage the product.
Install the unit only in the intended circuit with the documented polarity, supply mode, load, cooling and safety provisions. After installation, complete the prescribed functional check. External integrity alone does not demonstrate serviceability or calibration.
Related catalogue positions
Functionally related catalogue products include PO-750A, PO-1500 Series 4, PO-250A – ser. 2, PO-3000S. They are selected by actual type and family for navigation and do not imply compatibility. More positions are available in the Power Transducers category.
Enquiry information
An enquiry for PO-750A-2S should state the exact designation, quantity, required condition, marking photograph, delivery scope and required documents. When available, include the designation of the equipment and item being replaced. Price, actual availability, lead time and condition of a specific unit are confirmed separately.
Technical details
Product Type: Rotary Converter
Primary Designation: PO-750A-2S
Alternative Designations: PO-750A-2S; PO 750A 2S; ПО-750А-2С
Function: converts aircraft electrical power through an electromechanical motor-generator assembly
Selection Basis: Exact designation, execution, marking and documentation for the specific equipment
Application: Only as supported by the passport, illustrated parts catalogue or approved installation documentation
Interchangeability: Not established by a related designation, matching base, housing or appearance alone
Inspection: Verify electrical ratings, contacts or connector, mounting, construction and required operating mode
Enquiry Data: Designation, quantity, condition, marking photograph, delivery scope and required documents
Documentation: Product passport and approved operating or repair documentation
Category: Power Transducers
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Retained Technical Data:
Product Type: Rotary Converter
Primary Designation: PO-750A-2S
Alternative Designations: PO-750A-2S; PO 750A 2S; ПО-750А-2С
Function: converts aircraft electrical power through an electromechanical motor-generator assembly
Selection Basis: Exact designation, execution, marking and documentation for the specific equipment
Application: Only as supported by the passport, illustrated parts catalogue or approved installation documentation
Interchangeability: Not established by a related designation, matching base, housing or appearance alone
Inspection: Verify electrical ratings, contacts or connector, mounting, construction and required operating mode
Enquiry Data: Designation, quantity, condition, marking photograph, delivery scope and required documents
Documentation: Product passport and approved operating or repair documentation
Category: Power Transducers
Retained Technical Data:
Product Type: Aircraft single-phase electromechanical rotary converter
Function: Conversion of 27 V DC onboard power into 115 V / 400 Hz single-phase AC power
Application / Where Used: Power supply for radio, navigation, instrument and onboard equipment circuits
System / Installation Area: Aircraft electrical power supply system
Part of System / Included in Set: DC motor and single-phase synchronous generator on one shaft; starting and regulating equipment box
Compatible Aircraft / Equipment: An-24, An-26, Mi-8, Mi-26 and other aircraft requiring 115 V / 400 Hz single-phase AC supply
Input Voltage: 27 V DC
Consumed Current: 56 A; starting current 400 A
Output Voltage: 115 ± 3.5 V AC
Output Current / Load Current: 6.51 A
Rated Output Power: 750 VA
Output Frequency: 400 ± 16 Hz
Output Signal Form: Sinusoidal
Rotor Speed: 12,000 rpm; central bank switch 14,700 ± 200 rpm
Brush Type: MGS-8 aviation electrocarbon brushes
Weight: 14 kg
Technical Documentation: Aircraft electrical system documentation, parts catalog, repair manual, manufacturer technical documentation
Payment & delivery
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Dubai stock: 100% before dispatch. Partner stock (Remote stock) and Pre-order: 50% advance payment to start the order and 50% before shipment from Dubai to you.
Availability, lead time, delivery cost and payment terms are confirmed for your order before payment.
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