STG-12TMO-1000

STG-12TMO-1000 starter-generator for aircraft engines

The STG-12TMO-1000 is a DC aircraft starter-generator used on gas turbine engine installations where one unit must perform two jobs: start the engine and then supply electrical power after the engine has reached operating speed. In starter mode, the unit works as a powerful DC motor and rotates the engine through the accessory gearbox. After the engine start sequence is completed, the same machine changes to generator operation and supplies the aircraft DC network. This design reduces the number of separate electrical machines on the engine and keeps the installation more compact.

Starter operation of the STG-12TMO-1000

In starter mode, the STG-12TMO-1000 receives power from the aircraft or ground starting circuit and develops the torque needed to accelerate the engine during the start cycle. It is used with control equipment that manages the starting sequence, including voltage switching, high-current contactors, and automatic cut-off devices. The starter mode is short-term by nature and is not intended for continuous operation. Once the engine reaches the required speed, the starter circuit is disconnected, and the mechanical drive no longer works in the same starting condition.

Generator mode of the STG-12TMO-1000

After engine start, the STG-12TMO-1000 operates as a DC generator. In this mode, it produces electrical power for the onboard network and works together with voltage regulation and protection equipment. The generator mode is used during normal engine operation, where stable DC output is required for aircraft consumers. Correct generator performance depends not only on the unit itself, but also on the regulator, protection relays, wiring, brushes, cooling airflow, and the mechanical condition of the drive. Any weakness in these related elements can affect output voltage and load capability.

STG-12TMO-1000 with AI-20 engine installations

The STG-12TMO-1000 is closely associated with AI-20 turboprop engine installations and equipment based on these engines. It may be used on aircraft such as An-12, Il-18, Il-38 and on ground gas-turbine power units where AI-20-based installations are used. The unit is mounted on the engine accessory drive system and works as part of the starting and power-generation architecture. Before supply or replacement, the exact engine version, drive arrangement, and aircraft or power-plant documentation must be checked, because starter-generator installations can differ by modification and equipment set.

Control equipment used with STG-12TMO-1000

The STG-12TMO-1000 does not operate alone. In starter mode, it works with high-current contactors, start automation, and switching equipment that manage the current supplied to the unit. In generator mode, it is normally used with voltage regulation and protection devices, including voltage regulators and differential-minimum relays depending on the aircraft electrical system. Components such as RN-180 / RN-180M, DMR-400T, APD-30, VE-2T / VE-2TU, and TKS-series contactors may be associated with systems using this starter-generator, depending on the specific installation.

Brushes, cooling, and service points of STG-12TMO-1000

The STG-12TMO-1000 is a high-power rotating electrical machine, so brush condition, collector condition, cooling, and mechanical drive condition are central maintenance points. The unit uses MGS-7 brushes, and their condition affects both starting current transfer and generator output stability. In generator mode, forced air cooling is used to remove heat from the machine during load operation. During inspection, technicians usually check brush wear, collector surface, bearing condition, fastening points, connector condition, insulation resistance, and any signs of overheating or contamination inside the machine.

Identification and supply of STG-12TMO-1000

For procurement, repair, or overhaul, the full designation STG-12TMO-1000 should be used. It is also important to specify whether the requirement is for a serviceable unit, a repaired unit, an overhauled unit, or a unit for repair stock. Since the starter-generator works in both starting and power-generation modes, the documentation should confirm its electrical condition, mechanical condition, and test results in the required operating modes. For aircraft use, the unit should be supplied with passport, repair, storage, or acceptance documentation depending on condition and source.

Product Type: Aircraft DC starter-generator
Designation: STG-12TMO-1000
Function: Engine start in starter mode and DC power generation after engine start
Application / Where Used: Aircraft engine starting systems and DC power supply systems
System / Installation Area: Engine accessory gearbox / accessory drive installation
Primary Engine Application: AI-20 family turboprop engines
Other Applications: AI-20-based gas-turbine power units, PAES-2500, PAES-2500B, EG-2500 depending on configuration
Compatible Aircraft / Equipment: An-12, Il-18, Il-38 and other installations using AI-20 engines depending on configuration
Operating Mode 1: Starter mode
Starter Mode Voltage: 24 V or 48 V depending on starting circuit and switching sequence
Maximum Starter Current: 510 A
Starter Cut-Off Speed: Not more than 3200 rpm
Operating Mode 2: Generator mode
Generator Rated Voltage: 28.5 V DC
Generator Rated Current: 400 A
Rated Power: 12,000 W / 12 kW at 30 V
Generator Operating Speed Range: 4200–9000 rpm
Direction of Rotation: Left-hand rotation viewed from the drive side
Cooling: Forced air cooling in generator mode
Brush Type: MGS-7
Number of Brushes: 6 pcs
Brush Size: 9 × 20 × 28 mm
Dimensions: Diameter 199 mm; length 480 mm
Weight: Not more than 37 kg
Associated Mechanical Components: STG drive assembly, overrunning clutch, accessory drive components depending on installation
Associated Control / Protection Equipment: RN-180 / RN-180M, DMR-400T, APD-30, VE-2T / VE-2TU, TKS-series contactors depending on aircraft system
Technical Documentation: Product passport, test documentation, repair / overhaul documentation and aircraft maintenance documentation as applicable

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Returns & Changes (Restocking Fee)
For selected items, a RESTOCKING FEE of 10% may apply in case of return, order cancellation, or changes to the order specifications. This condition applies only to certain products and is confirmed at the order approval stage.

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.