KR-12SI
Ignition Starting Coil
Description
KR-12SI starting coil in aircraft ignition systems
The KR-12SI is an aircraft ignition starting coil used during engine or auxiliary power unit start. It is part of the ignition circuit, not a control unit and not a starter motor. The coil takes low-voltage DC power from the aircraft electrical system and produces high-voltage pulses for the ignition plug. In service, it is normally checked together with the ignition plug, high-voltage lead, power supply circuit, grounding path, and the start control equipment connected to the engine or APU.
Full descriptionCollapse description
High-voltage pulse generation by KR-12SI
The KR-12SI works through an induction circuit with an electromagnetic interrupter. During the start cycle, the coil converts onboard DC voltage into pulsed high voltage. These pulses are sent to the ignition plug, where the spark ignites the fuel-air mixture in the combustion chamber or APU starting system. The unit operates cyclically and is not intended for continuous operation. If there is no spark during start, the fault may be in the coil, but it may also be in the plug, cable, connector, ground contact, or supply circuit.
KR-12SI with AI-8, AI-9 and AI-9V units
The KR-12SI is used in ignition systems of AI-8, AI-9 and AI-9V engines and auxiliary power units. These installations are found on aircraft and helicopters such as Mi-8, Mi-10, Mi-24, Ka-27, Ka-32, Ka-50, Ka-52, Be-12 and An-140. The same coil type may be used in different ignition layouts, so the installation should be checked against the aircraft or APU documentation. For example, cable routing, plug type, grounding point and mounting position may vary by platform and modification.
Shielded housing and wiring of KR-12SI
The KR-12SI is built in a hermetically sealed shielded metal housing. This construction helps protect the internal coil assembly and reduces electromagnetic interference from high-voltage pulse operation. The electrical connection follows a single-wire scheme, with the negative side connected through the housing. In a real installation, clean grounding is important. Poor contact at the housing or mounting point can create symptoms similar to a defective coil, especially during troubleshooting after maintenance or replacement of adjacent ignition parts.
Identification and ordering of KR-12SI
Before ordering KR-12SI, the marking on the unit should be compared with the aircraft parts catalog, APU documentation, or product passport. It is also useful to confirm the connected ignition plug and high-voltage lead, especially when the aircraft has passed repair or partial modernization. SD-55ANM type ignition plugs may be used in related systems, but the exact configuration must follow the technical documentation. The product is also known under alternative designations KR-12SI and КР-12СИ.
Technical details
- Product Type
- Ignition starting coil (high-voltage induction type)
- Function
- Generation of high-voltage pulses for ignition during engine start
- Application / Where Used
- Aircraft engine and APU ignition systems
- System / Installation Area
- Ignition system
- Compatible Aircraft / Equipment
- AI-8, AI-9, AI-9V engines; Mi-8, Mi-10, Mi-24, Ka-27, Ka-32, Ka-50, Ka-52, Be-12, An-140
All specificationsCollapse specifications
- Operating Voltage
- 18 to 32 V DC (27 V nominal ±10%)
- Output Voltage
- 12,000 to 15,000 V (pulsed)
- Current Consumption
- 2.3 to 2.5 A (at 24 V)
- Operating Mode
- Intermittent (cyclic)
- Operating Temperature Range
- −40 to +80 °C
- Dimensions
- 141 × 74 × 62 mm
- Weight
- ≤ 0.6 kg
- Electrical Scheme
- Single-wire (negative to корпус)
- Construction
- Hermetically sealed shielded metal housing
- Compatible Components
- Ignition plug (e.g., SD-55ANM); high-voltage lead
- Technical Documentation
- Product passport and operational documentation
- Designation
- KR-12SI
- Alternative Designations
- KR12SI; КР-12СИ; КР12СИ
- Related Equipment
- SK-22-2K, SK-22-2M, SD-55ANM-T
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