STG-12TMO-1000
Starter-Generator
Description
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.
Full descriptionCollapse description
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.
Technical details
- 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
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- 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
Payment & delivery
Orders ship from our hub in Dubai. Partner stock is first transferred to Dubai, then shipped to you.
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.
Payment & delivery terms


