S2519-5 - Textron Aviation OEM High Voltage Warning Lamp Assembly Replaces S2519-1

S2519-5 – Textron Aviation "HIGH VOLTAGE" Warning Lamp Assembly (Replaces S2519-1)

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The S2519-5 is the current production, genuine Textron Aviation (Cessna) OEM part number for the flight-critical "HIGH VOLTAGE" warning lamp assembly. This part directly replaces and supersedes the previous part number S2519-1. This component is the pilot's primary visual annunciator for the aircraft's overvoltage protection system. Its sole, indispensable function is to illuminate a red warning, alerting the crew that the alternator's voltage regulator has failed, the overvoltage sensor has automatically taken the alternator offline, and the aircraft is now operating solely on battery power.

This assembly consists of the lamp housing, a red annunciator lens cap typically inscribed with "HIGH VOLTAGE" or "VOLTS," and the internal incandescent bulb and socket. It is engineered with a "press-to-test" feature, allowing the pilot to verify the integrity of the bulb before every flight. The reliability of this warning light is paramount, as it is the pilot's first and only indication of a critical electrical system failure that requires immediate action.

Key Features

• Genuine Textron Aviation OEM Part: The current, factory-authorized part, ensuring you receive the latest production revision and full compliance with the aircraft's type certificate.

• Direct Replacement for S2519-1: Engineered as a direct, form-fit-function replacement for the previous part number.

• Provides Critical Overvoltage Warning: The primary visual alert for an alternator overvoltage condition and subsequent trip-offline event.

• Red Lens with "HIGH VOLTAGE" Annunciation: The red color and clear text provide an unmistakable warning of a serious electrical system malfunction.

• Press-to-Test Functionality: The lens cap is designed to be pressed, which completes a secondary circuit to test the bulb's integrity, a critical pre-flight check item.

Technical Specifications

• Part Number: S2519-5

• Supersedes: S2519-1

• Component Type: Annunciator / Warning Lamp Assembly

• OEM Manufacturer: Textron Aviation (Cessna)

• Annunciation: "HIGH VOLTAGE" or "VOLTS"

• Lens Color: Red

• Lamp Type: Incandescent (utilizes a replaceable bulb).

• System Voltage: Designed for 14 VDC or 28 VDC aircraft electrical systems, as specified by the aircraft model.

Aircraft Compatibility

The S2519-5 is the standard overvoltage warning lamp assembly on a vast range of Textron Aviation (Cessna) single-engine aircraft. Common applicable models include, but are not limited to:

• Cessna 172 Skyhawk

• Cessna 177 Cardinal

• Cessna 182 Skylane

• Cessna 206 Stationair

• Cessna 210 Centurion

Crucial Note: The specific aircraft model and serial number must be checked against the latest revision of the official Textron Aviation (Cessna) Illustrated Parts Catalog (IPC) to ensure correct part number applicability.

Applications

• Instrument panel annunciator for the alternator control unit (ACU) / overvoltage protection system.

• Provides a visual warning to the pilot in the event of a charging system failure.

Why Choose S2519-5?

Choosing the genuine Textron S2519-5 ensures you are installing the latest, certified revision of this critical warning component. The overvoltage light is a required safety device, and an inoperative lamp could leave a pilot completely unaware that their alternator has failed, leading to a potential total loss of electrical power in flight. The genuine OEM part guarantees perfect integration with the aircraft's electrical and warning systems, ensuring that this life-saving alert will function as designed and maintain the aircraft in its original, factory-certified configuration.

The S2519-5 lamp assembly is the final component in an elegant and robust overvoltage protection circuit. The aircraft's alternator control unit (ACU) or a separate overvoltage sensor continuously monitors the main electrical bus voltage. This control unit contains a voltage reference circuit, typically built around a Zener diode or a precision integrated circuit with a very sharp breakdown voltage threshold (e.g., 32.5V for a 28V system). If a failure in the alternator's voltage regulator causes the bus voltage to exceed this threshold, the sensor circuit triggers a silicon-controlled rectifier (SCR). The SCR acts as a high-speed, solid-state switch that, once triggered, creates a low-resistance path to ground. This action, known as a "crowbar" circuit, serves two simultaneous functions: 1) it shunts a high current that trips the alternator field circuit breaker or a control relay, removing the excitation voltage from the alternator and causing its output to drop to zero, and 2) it closes the secondary circuit path for the warning lamp, providing a ground to illuminate the bulb. This automated protective action saves the aircraft's avionics from destructive overvoltage, and the lamp provides the pilot with the unambiguous indication that this event has occurred.

Note: This is a flight-critical safety and warning system component. The "press-to-test" function of this lamp should be utilized as part of the pre-flight checklist to ensure the bulb is operational. An inoperative warning light renders the overvoltage protection system annunciator unserviceable and must be repaired prior to flight. Installation must be performed by a certified A&P or avionics technician in accordance with the Textron/Cessna maintenance manual.

Documentation

The definitive part number applicability and all wiring and installation procedures are detailed in the applicable Textron Aviation (Cessna) Illustrated Parts Catalog (IPC) and Wiring Diagram Manual for the specific aircraft model and serial number.