PO-500 Series 2

Power conversion function of PO-500 Series 2

In operation, the PO-500 Series 2 receives 27 V DC from the aircraft electrical system. The DC motor drives the generator section, and the generator produces single-phase AC output for connected onboard equipment. This layout was widely used before solid-state converters became common. It is simple in logic but mechanical in execution. During maintenance, voltage, frequency, current draw, brush condition and rotation stability matter more than external appearance. A clean housing does not always mean the unit is electrically serviceable.

PO-500 Series 2 in avionics and instrument circuits

The converter is used where aircraft equipment needs stable AC power independent of the main AC system or where the aircraft has mainly DC generation onboard. Typical loads include radio navigation units, communication equipment, instrument circuits and auxiliary avionics blocks. In practical installations, the PO-500 Series 2 may feed separate buses or dedicated consumers, depending on the aircraft wiring. For replacement, the installed converter should be checked against the aircraft electrical diagram and equipment list, not only by model name.

Construction of the PO-500 Series 2 converter

The PO-500 Series 2 consists of two electrical machines assembled in one housing: a DC motor and a synchronous single-phase generator. The motor section has field windings on its poles. The generator section has a fixed magnetic system and a rotating armature. Current collection in the generator is made through contact rings. The unit is made in a protected design with through-flow self-ventilation, so airflow is part of normal operation. Blocked ventilation, brush wear or poor bearing condition can affect output quality.

Identification and ordering of PO-500 Series 2

Before ordering, the converter marking should be compared with the aircraft parts catalog, electrical equipment list or repair documentation. PO-series converters exist in different power ratings and versions, so the series number matters. For a correct match, it is better to provide the aircraft type, installed equipment list, supply voltage, required output voltage and the exact marking from the data plate. The product is also known under alternative designations PO-500 Series 2, PO-500 2nd series and ПО-500 серия 2.

Confirmed installation context includes Mi-8 / Mi-17 family helicopters. Exact applicability of the specific execution must be verified against the aircraft technical documentation.