S1579-1 - Lamar Technologies Contactor Assembly

S1579-1 – Lamar Technologies Contactor Assembly

Available now on the Airparts.aero Marketplace.

Overview

The Lamar Technologies S1579-1 is a flight-critical contactor assembly, an essential component in the high-current electrical systems of various Textron Aviation aircraft. This is not a simple relay; it is a heavy-duty, intermittent-duty solenoid-actuated switch, engineered to handle the immense current draw of the engine starter motor. The S1579-1 functions as the primary starter relay, using a low-current signal from the cockpit start switch to safely close a high-power circuit, delivering hundreds of amps from the battery directly to the starter. Its robust construction and high-current capacity are fundamental to ensuring reliable engine starts.

This genuine OEM-quality component from Lamar Technologies, a leader in aerospace electrical systems, guarantees the performance and durability required for this demanding application. Its design ensures a solid, low-resistance connection, maximizing the power delivered to the starter for faster, cooler engine starts.

Key Features

• High-Current Switching Capability: Engineered to handle the massive, inrush current of an aircraft starter motor, which can often exceed 500 amps for a short duration. The large, silver alloy contacts are designed to resist arcing and welding under these extreme loads.

• Intermittent Duty Cycle: Specifically designed for the intermittent, high-load duty cycle of an engine starter. The electromagnetic coil is designed for short-term energization, providing a powerful pulling force to close the main contacts.

• Robust, Vented Housing: The contactor is housed in a durable, vented enclosure. The venting helps to dissipate the significant heat generated during the high-amperage start sequence, protecting the internal coil and contacts.

• Corrosion-Resistant Terminals: Features large, copper or copper-alloy high-current terminals and smaller control terminals, all of which are plated to resist corrosion and ensure a low-resistance electrical connection.

• OEM-Quality Standard: As a component from a leading OEM supplier, it guarantees the correct coil resistance, contact material, and mounting configuration for a direct, airworthy replacement on specified Textron aircraft.

Superscedure Hierarchy

• S1579-1 - Original
• S1579A2 - Replaces original
• P52-0034-1 - Current primary part

Technical Specifications

• Part Number: S1579-1

• Component Type: Starter Contactor / Relay Assembly

• OEM Manufacturer: Lamar Technologies

• Voltage: Designed for 28 VDC aircraft systems.

• Duty Cycle: Intermittent

• Contact Configuration: Single Pole, Single Throw, Normally Open (SPST-NO)

• High-Current Terminals: 5/16-24 studs

• Control Terminals: #10-32 studs

• Certification: FAA Production Approval

Aircraft Compatibility

The Lamar S1579-1 is the specified OEM starter contactor for a wide range of Textron Aviation's high-performance piston and turboprop aircraft. It is imperative to consult the specific aircraft's Illustrated Parts Catalog (IPC) for final verification.

• Primary Aircraft Models:

  • Textron Aviation (Beechcraft): Baron 58, Bonanza 36 series

  • Textron Aviation (Cessna): Piston singles and twins (various models)

Applications

The S1579-1 is a flight-critical component with a singular, vital purpose:

• Engine Starting: Its sole function is to act as the heavy-duty remote switch that completes the circuit between the aircraft battery and the engine starter motor when the pilot activates the start switch.

• Component Replacement: The primary component to replace when troubleshooting a "no-crank" or "clicking" starter, after verifying the health of the battery and starter motor.

Why Choose S1579-1?

The ability to reliably start an engine is a fundamental requirement for any aircraft. A failure of the starter contactor can leave an aircraft stranded. The Lamar S1579-1 is a robust, OEM-quality component designed to handle the massive electrical loads of engine starting without failing. Common failure modes of lesser-quality contactors include welded contacts (starter won't disengage) or burned contacts (starter won't engage). Using a high-quality, certified part from a trusted OEM supplier like Lamar is a critical investment in the reliability of your aircraft's starting system.

The Lamar S1579-1 contactor is an electromechanical device designed to solve the problem of switching a very high-current circuit with a small, low-current switch. The large-gauge cables required to carry hundreds of amps from the battery to the starter are too heavy and cumbersome to route all the way to the cockpit start switch. Instead, the S1579-1 is mounted in the engine compartment, close to the battery and starter. The low-current start switch in the cockpit sends a small amount of electricity (typically less than 1 amp) to the contactor's internal electromagnet. This electromagnet generates a powerful magnetic field that pulls a plunger, which in turn slams a heavy copper disc across the two main terminals, completing the high-current circuit. This use of a remote-mounted, heavy-duty relay is fundamental to the design of a safe and efficient aircraft electrical system.

Note: This is a flight-critical, high-amperage electrical component. Installation must be performed by a certified A&P mechanic. The battery must be disconnected before installation. All high-current and control terminals must be clean and torqued to the specified value to prevent high resistance, heat buildup, and a potential fire hazard.