Title
L-849-V-A/E / L-849-I-A/E Runway End Identifcation Lights (REIL) - Overview and Application
URL Name
L-849-V-A-E-L-849-I-A-E-Runway-End-Identifcation-Lights---Overview-and-Application
Summary
This article provides an overview, general descriptions, equipment specifications, access information, and applications for the L-849-V-A/E voltage-powered and L-849-I-A/E current-driven unidirectional runway approach lights manufactured by Strobe Approach Lighting Technology (SAL Technology).

Content

Product Identification

L-849-V-A/E - Uni-directional Voltage-Powered Runway End Identification Lights (REIL).
L-849-I-A/E - Uni-directional Current-Driven Runway End Identification Lights (REIL).

FAA Style

FAA Style | Flashhead Type | Intensities
A | Unidirectional | High
E | Unidirectional | Low, Medium, High

Theory of Operation - Both Models

A xenon capacitive discharge light is often referred to as a “strobe”. A flash is produced when sufficient electrical energy is abruptly ‘dumped’ into a lamp filled with xenon gas. The gas, which is normally nonconductive, must be brought to a conductive state for a flash to occur. This requires applying a pulse of high amplitude (a triggering pulse) to the lamp. The energy producing the flash is stored in a bank of capacitors connected to the lamp electrodes. The capacitors, charged to a relatively high potential, discharge through the lamp when the internal gas becomes conductive. SAL Technology strobes consist of two major subassemblies called power supplies and flash heads. A power supply converts external ac primary power to dc (direct current) that is fed to a bank of energy storage capacitors bringing them to a charge potential of about 1000 Volts dc (±500 Volts). Most runway approach strobes must be capable of 3 levels of flash intensity–High, Medium, and Low. Flash intensity levels are changed by switching the lamp to different values of bank capacitance. Flash head components consist of a sealed-beam xenon lamp, a triggering transformer, and additional minor circuitry. The flash head is connected to the power supply by a short harness if it is co-mounted or by a cable when it is installed remotely. The harness/cable connects the bank of capacitors in the power supply to the anode and cathode flash lamp electrodes. The maximum voltage on the anode conductor is +500 Volts dc. The maximum voltage on the cathode conductor is –500 Volts dc. The total lamp voltage at discharge is therefore 1000 volts. The harness/cable also carries a low level triggering pulse that is applied to a small transformer in the flash head where it is boosted to a voltage level high enough to trigger the flash lamp into its conductive state. A coupling transformer located in the power supply provides an intermediate signal boost that improves triggering when a very long flash head cable is used. A REIL system has two lights that flash simultaneously. These lights must always operate as an integrated system. This requires a form of communication between the lights. The method used in SAL Technology systems is an encoded signal that is distributed by an interconnecting control line. The encoded signal carries timing and flash intensity information that originates at a master unit. The only difference between a master unit and a slave unit is an internal control module residing in the master unit. The control module monitors the current in a Series Lighting Circuit and provides adjustments for setting intensity switching thresholds at specific levels of SLC current.

General Information

  • A flashing runway approach light consists of a power supply and a flash head. 
  • The power supply may be either a master unit or a slave.
  • The flash head may be attached directly (co-mounted) to a power supply enclosure or installed separately and connected by up to 100 feet of suitable cable.
  • The systems can operate as FAA Style A and E (L-849).
  • The lights are used for Runway End Identifier Lights (REIL) to identify the approach end of a runway and provide guidance to pilots during approach for landing.
  • These lights also meet the photometric and functional requirements for discharge flashers in high or medium intensity precision Approach Lighting Systems (ALS).
  • This equipment meets or exceeds the requirements in the FAA Advisory Circular, AC 150/5345-51 (Current Edition), and is listed as FAA approved equipment in AC 150/5345-53, Addendum B.
  • L-849V lights and L-849I lights from SAL Technology are certified by third party testing under the FAA's Airport Lighting Equipment Certification Program (ALECP). 

Equipment Specifications - L-849-I-A/E Current-Driven

Physical dimensions are in inches (mm); weight in lbs (kg).
Power Supply:
- Dimensions: 8H x 16W x 14D (203 x 406 x 356).
- Weight: 47 (21.3).
Flash Head:
- Dimensions: 11.5H x 8.5W x 7D (292 x 216 x 178).
- Weight: 4.5 (2).
Co-mounted Power Supply and Flash Head:
- Dimensions: 19.5H x 16W x 14D (495 x 406 x 356).
- Weight: 51.5 (23.3).
Operational:
- Current (rms Amps): 2.8 to 6.6.
- Power (Watts): 150 Ave, 290 Peak.
- Flash Rate (Flashes Per Minute): 120.
- Intensity (Effective Candelas, Nominal): High: 15000; Med: 1500; Low: 300.
- Beam Spread: 30º Horizontal, 10º Vertical.
Available Options (Must be factory installed):
- Flash Monitoring.
- Elapsed Time Meter.

Equipment Specifications - L-849-V-A/E Voltage-Powered

Physical dimensions are in inches (mm); weight in lbs (kg).
Power Supply:
- Dimensions: 8H x 16W x 14D (203 x 406 x 356).
- Weight: 52 (23.6).
Flash Head:
- Dimensions: 11.5H x 8.5W x 7D (292 x 216 x 178).
- Weight: 4.5 (2).
Co-mounted Power Supply and Flash Head:
- Dimensions: 19.5H x 16W x 14D (495 x 406 x 356).
- Weight: 56.5 (25.7).
Operational:
- Voltage (rms): 120 or 240 Volts, 60 Hz; 230 Volts, 50 Hz.
- Power (Watts): 150 Ave, 290 Peak.
- Flashes Per Minute: 120.
- Intensity (Effective Candelas, Nominal): High: 15000; Med: 1500; Low: 300.
- Beam Spread: 30º Horizontal, 10º Vertical.
Available Options (Must be factory installed):
- Remote Control by a Series Lighting Circuit.
- Flash Monitoring.
- Elapsed Time Meter.

General Description - L-849-V-A/E Voltage-Powered

A flashing runway approach light from SAL Technology consists of a power supply and a flash head. The power supply may be either a master unit or a slave. The catalog designation for a Master Power Supply is 255-20001. A Slave Power Supply is 255-20002. The Flash Head in either case is 255-20009. The flash head may be attached directly to a power supply enclosure (co-mounted) or installed separately and connected by up to 100 feet of suitable cable. This equipment is classified as a unidirectional discharge flasher (strobe) that operates from 120 or 240 V, 60 Hz (specify when ordering). It can also be provided to operate at 230 Volts, 50 Hz. It is specifically designed and tested to meet the requirements for L-849V applications as defined by the FAA in “Specification for Discharge-Type Flashing Light Equipment”, AC 150/5345-51 (Current Edition). L-849V is the designation applied by the FAA to voltage-driven Runway End Identification Lights (REIL).

General Description - L-849-I-A/E Current-Driven

A flashing runway approach light from SAL Technology consists of a power supply and a flash head. A power supply may be either a master unit or a slave. The catalog designation for a Master power supply is 255-20003. A Slave power supply is 255-20004. The Flash Head in either case is 255-20009. The flash head may be attached directly (co-mounted) to a power supply enclosure or installed separately and connected by up to 100 feet of suitable cable. The cable can be furnished by SAL Technology. This equipment is classified as a unidirectional discharge flasher (strobe) that operates from a Series Lighting Circuit driven by an L-828 Constant Current Regulator, Class 1, Style 1 or 2. This equipment does not require an intermediate Series Circuit Adapter. It is specifically designed and tested to meet the requirements for L-849I applications as defined in the FAA's "Specification for Discharge-Type Flashing Light Equipment", AC 150/5345-51B. L-849I is the designation used by the FAA for a current-driven flashing light for Runway End Identification Lights (REIL).

Applications - Both Models

  • These lights may be used in REIL applications.
  • The lights in a REIL system must flash simultaneously. 
  • Switch SW1 on PCB-1 controls when the light will flash (simultaneously or sequentially).
  • SW2 controls the rate at which flashes repeat (generally 120 flashes per minute).
  • These switches are initially set at the factory to comply with the application as ordered, although changes can easily be made in the field.
  • Switch programming diagrams are attached to the inside cover of every power supply.

 

Airport Lighting Company | L-849-V-A/E / L-849-I-A/E Unidirectional Runway Approach Lights - Overview and Applications

Runway End Identifier Light

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