Ferroresonant Constant Current Regulator for Airfield Ground Lighting
Controlled series-circuit current, matched to the whole circuit
A Ferroresonant Constant Current Regulator (CCR) provides controlled electrical current to series-circuit Airfield Ground Lighting systems, supplying runway, taxiway, approach and associated circuits at defined operating current levels. Precision AGL Solutions supplies ferroresonant CCR solutions selected for rated current, input voltage, output characteristics, brilliance settings, control interface, protection requirements and installation conditions.
The Controlled Power Source for a Series Circuit
In a typical series-circuit AGL installation the regulator supplies controlled current through the primary circuit, and individual fixtures connect to it through isolating transformers. The CCR, cable, transformers and fixtures should be considered as one coordinated electrical system.
The regulator forms an important part of the AGL power system and should be selected together with the connected fixtures, isolating transformers, primary cable and other series-circuit components.
Where Ferroresonant CCRs Are Used
The final CCR configuration should be determined from the complete series-circuit load and the applicable project requirements.
Ferroresonant Regulation and Constant Current
Ferroresonant Regulation
- Uses a ferroresonant magnetic circuit to provide controlled current characteristics
- Configuration selected from the electrical requirements of the AGL circuit
- Rated output current and input voltage
- Output characteristics and connected circuit load
- Required intensity steps and control arrangement
- Protection and cooling requirements, installation environment
Constant Current Operation
- Selected for the current the circuit needs, not the nominal fixture voltage
- Number of installed lights and light type
- Isolating transformer ratings
- Primary cable length and circuit impedance
- Circuit configuration and maximum circuit voltage
- Required operating current and brilliance settings
Exact electrical characteristics should be confirmed from the selected equipment's technical documentation.
Brilliance / Intensity Steps
Where required, the CCR can be configured for multiple operating steps. Different intensities may be needed for different airport operating conditions, so the number and values of steps should be established from the project lighting design and control requirements.
- Number of intensity levels
- Required circuit current at each level
- Connected fixture characteristics
- Airport control philosophy
- Local control requirements
- Remote control requirements
- Existing AGL control infrastructure
The final step configuration should be confirmed during system design.
Input, Output, Control and Protection
Input Voltage
- Rated supply voltage
- Supply frequency
- Phase arrangement
- Input protection
- Incoming feeder capacity
- Earthing arrangement
Output Characteristics
- Rated output current
- Output voltage capability
- Circuit load range
- Intensity-step characteristics
- Regulation characteristics
- Connected circuit impedance
- Maximum operating conditions
Control & Protection
- Local operation
- Remote intensity selection
- Run/stop and step selection
- Status and alarm indication
- Control-system interface
- Protection of input, output, internal components, temperature, overload, faults and control circuits
Confirm input supply from the project electrical drawings and output characteristics from the series-circuit calculation. For replacements, review the existing control arrangement first, and coordinate alarm interfaces with the airport's AGL control and monitoring system.
Cooling Requirements
Ferroresonant CCR equipment produces heat during operation and must be installed with suitable thermal management. Cooling requirements depend on:
- Regulator rating
- Operating load
- Installation environment
- Ambient temperature
- Enclosure configuration
- Ventilation arrangement
- Duty cycle
The location should provide the ventilation and clearance specified for the selected equipment. For enclosed CCR rooms or cabinets, available heat dissipation capacity should be considered during design.
Project Selection Requirements
| Parameter | Project Selection Requirement |
|---|---|
| Product Type | Ferroresonant Constant Current Regulator |
| Application | AGL series-circuit lighting |
| Rated Current | Project-specific |
| Input Voltage | Project-specific |
| Input Frequency | Project-specific |
| Output Characteristics | According to connected series circuit |
| Intensity Steps | Project-specific; commonly 3-step or 5-step, with 6.6 A at the highest step on 6.6 A circuits (FAA 6.6 A circuits: 4.8 / 5.5 / 6.6 A for 3-step; 2.8 / 3.4 / 4.1 / 5.2 / 6.6 A for 5-step. FAA 20 A circuits, 5-step: 8.5 / 10.3 / 12.4 / 15.8 / 20 A) |
| Control Interface | Local and/or remote as specified |
| Protection | Equipment- and project-specific |
| Monitoring | According to selected configuration |
| Cooling | According to regulator rating and installation |
| Dimensions | Model-specific |
| Weight | Model-specific |
| Installation | Suitable CCR equipment location |
| Series-Circuit Compatibility | To be verified during system selection |
Final technical values should be confirmed against the selected CCR model and project datasheet before procurement.
CCR Sizing and Circuit Compatibility
Sizing should be based on the actual electrical characteristics of the complete AGL series circuit. Important information for selection:
Integration with Airfield Series Circuits
The CCR should be coordinated with all major components of the series circuit, and its rating should account for the complete connected load.
Changes to the number of fixtures, transformer ratings or cable arrangement can affect the electrical requirements of the CCR.
Installation Considerations
Installation requirements should be established from the selected equipment documentation and project electrical design. The CCR should be installed in a location suitable for its electrical and thermal requirements.
- Suitable installation location
- Adequate ventilation
- Required equipment clearances
- Incoming power connection
- Series-circuit output connection
- Control and alarm wiring
- Earthing and cable routing
- Accessibility and maintenance access
- Environmental conditions
Replacement Applications
Ferroresonant CCRs can be considered for replacement and rehabilitation projects where existing airport lighting infrastructure is retained or upgraded. Before replacing a regulator, review:
- Existing regulator rating
- Existing input supply
- Existing output current
- Connected series-circuit load
- Number of intensity steps
- Existing control interface
- Alarm requirements
- Existing installation dimensions
- Cable terminations
- Cooling arrangement
- Existing circuit condition
Select the replacement from the actual circuit requirements, not simply by matching the nameplate rating of the old regulator.
Commissioning Checks
Commissioning should verify the CCR and its interaction with the complete series-circuit lighting system. Typical checks:
- Verification of incoming supply.
- Inspection of power and control connections.
- Verification of earthing.
- Inspection of series-circuit connections.
- Verification of circuit continuity.
- Verification of insulation condition as applicable.
- Measurement of regulator output current.
- Verification of intensity steps.
- Testing of local controls.
- Testing of remote-control commands where applicable.
- Verification of alarm and status interfaces.
- Functional testing of the connected lighting circuit.
Follow the manufacturer's instructions and approved project testing requirements.
Maintenance and Troubleshooting
Regular inspection supports reliable operation: visual inspection, cleaning, ventilation paths, electrical connections, signs of overheating, control and intensity-step operation, alarm testing, output-current verification, fault indications and cooling arrangements. Intervals should follow the selected equipment and the airport's maintenance program. A CCR fault should be investigated as part of the complete AGL series circuit.
Quotation Checklist
For a CCR technical selection or quotation, provide:
- Application
- Runway/taxiway/approach circuit type
- Required rated current
- Input voltage and frequency
- Number of connected fixtures
- Fixture type
- Isolating transformer ratings
- Primary cable information
- Required intensity steps
- Control interface
- Existing CCR make/model and rating
- Installation location
- Cooling arrangement
- Project specification
- Required quantity
For replacements, photographs of the existing CCR nameplate and control connections help establish compatibility.
Electrical Safety — Isolation and Lock-Out
WARNING — never open a live series circuit. An open series circuit driven by a constant-current regulator can produce dangerously high voltage. Opening, cutting or disconnecting any part of an energised circuit can cause serious injury or death and damage equipment.
- De-energise the circuit at the regulator and apply the site lock-out / tag-out (LOTO) procedure before any work
- Where the circuit must be isolated or shorted, use the series circuit cut-out switch or approved isolation device — not an improvised bypass
- Verify the circuit is de-energised and the output is isolated before touching conductors, connectors, splices or transformers
- Where the site procedure requires it, short and earth the circuit at the work location with approved equipment to discharge residual or induced voltage before touching conductors
- Work only under the airport's permit-to-work system, using qualified personnel and the manufacturer's instructions
- Follow the applicable national electrical safety regulations and site procedures
CCR Specification and Ratings
FAA Specification
Constant current regulators and regulator monitors for airport lighting series circuits are covered by FAA AC 150/5345-10H — Specification for Constant Current Regulators and Regulator Monitors. Confirm the current edition and the applicable class/style designation with the manufacturer datasheet.
Ferroresonant CCRs are designated L-828 (60 Hz) and L-829 (50 Hz); for 50 Hz networks such as India, specify L-829. Class 1 covers 6.6 A circuits and Class 2 covers 20 A circuits; Style 1 is 3-step and Style 2 is 5-step.
Also review IEC 61822, ICAO Annex 14 / Doc 9157 Part 5 and the applicable national electrical requirements for the project.
Ratings to Specify
- Regulator rating (kVA) matched to the connected circuit load
- Rated output current and available current steps (for example 3-step or 5-step brightness control)
- Input supply voltage and frequency
- Regulator class/style per the applicable specification
- Circuit load range: ferroresonant regulators hold output current only within a defined load range, so check the circuit stays inside it after any fixture change
- Open-circuit, over-current and over-voltage protection, and a regulator monitor where required
- Monitoring and remote-control interface
Exact kVA and current ranges offered are supplied on the manufacturer datasheet for the project.
Standards, References and Documents
Standards and References
- ICAO Annex 14 Vol. I (Chapter 8, electrical systems) and Doc 9157 Part 5
- FAA AC 150/5345-10H (CCR and regulator monitors) and AC 150/5340-26C (maintenance)
- IEC 61822 — constant current regulators for aerodrome lighting
- DGCA India CAR Section 4 and national electrical requirements
- Airport authority specifications
- Project-specific AGL specifications
- Approved electrical drawings
- Equipment manufacturer's requirements
Documentation
- Product datasheet
- Electrical specifications
- Input/output characteristics
- General arrangement drawing
- Control-interface and protection information
- Wiring diagrams
- Installation, commissioning and maintenance instructions
- Spare-parts information
Verify the applicable standard edition and project specification before procurement. Confirm documentation requirements in the procurement specification.
Support Matched to Your Circuit
Precision AGL Solutions supports the selection and integration of CCR equipment for airport series-circuit lighting systems, so the selected CCR is matched to the electrical characteristics and operational requirements of the associated circuit.
Ferroresonant Constant Current Regulator — Frequently Asked Questions
What is a ferroresonant constant current regulator?
A ferroresonant CCR uses a ferroresonant magnetic circuit to provide controlled current to series-circuit Airfield Ground Lighting, supplying runway, taxiway, approach and associated circuits at defined operating current levels. The regulator, primary cable, transformers and fixtures should be considered as one coordinated electrical system.
What are the L-828 and L-829 designations?
Ferroresonant CCRs are designated L-828 for 60 Hz and L-829 for 50 Hz under FAA AC 150/5345-10H. For 50 Hz networks such as India, specify L-829. Class 1 covers 6.6 A circuits and Class 2 covers 20 A circuits, while Style 1 is 3-step and Style 2 is 5-step. See also the thyristor CCR page.
What are the standard intensity step currents?
On FAA 6.6 A circuits, a 3-step regulator uses 4.8 / 5.5 / 6.6 A and a 5-step regulator uses 2.8 / 3.4 / 4.1 / 5.2 / 6.6 A. On FAA 20 A circuits, a 5-step regulator uses 8.5 / 10.3 / 12.4 / 15.8 / 20 A. The number and values of steps should be established from the project lighting design and control requirements.
How is a CCR sized for a series circuit?
Size it on the actual electrical characteristics of the complete circuit, not nominal fixture voltage: the application, the number and type of fixtures, isolating transformer ratings, primary cable length and impedance, required current and intensity steps, input supply, and control requirements. Changes to fixture count, transformer ratings or cable arrangement can affect the CCR requirement.
What cooling does a ferroresonant CCR need?
It produces heat during operation and needs suitable thermal management. Cooling depends on the regulator rating, operating load, ambient temperature, enclosure configuration, ventilation and duty cycle. For enclosed CCR rooms or cabinets, consider available heat dissipation capacity during design.
What control and protection functions are available?
Depending on configuration, local operation, remote intensity selection, run/stop and step selection, status and alarm indication, a control-system interface, and protection of input, output, internal components, temperature, overload, faults and control circuits. Coordinate alarm interfaces with the airport AGL control and monitoring system.
What should be reviewed before replacing an existing regulator?
Review the existing regulator rating, input supply, output current, connected series-circuit load, number of intensity steps, control interface, alarm requirements, installation dimensions, cable terminations, cooling arrangement and circuit condition. Select the replacement from the actual circuit requirements, not simply by matching the nameplate rating of the old regulator.
What is checked at commissioning?
Verify the incoming supply, power and control connections, earthing, series-circuit connections, continuity and insulation condition, measure the regulator output current, verify the intensity steps, test local and remote controls and alarm and status interfaces, and carry out functional testing of the connected lighting circuit.
What should I investigate when the circuit does not operate or alarms repeat?
For a circuit not operating, check incoming power, CCR status, control command, protection status, output connection, series-circuit continuity, primary cable and isolating transformers. For incorrect intensity, check the selected step, output current, connected load and transformer configuration. For repeated protection or alarms, investigate rather than repeatedly reset.
Is it safe to disconnect part of an energised series circuit?
No. An open series circuit driven by a constant-current regulator can produce dangerously high voltage, and opening, cutting or disconnecting any part of an energised circuit can cause serious injury or death. De-energise at the regulator, apply lock-out / tag-out, use the series circuit cut-out switch or approved isolation device and work under the permit-to-work system. See the electrical safety warning on this page.
What information should I provide for a CCR quotation?
Provide the application and circuit type, required rated current, input voltage and frequency, number of connected fixtures and fixture type, isolating transformer ratings, primary cable information, required intensity steps, control interface, existing CCR make, model and rating for replacements, installation location, cooling arrangement, project specification and quantity. Photographs of the existing CCR nameplate and control connections help.
Procurement Information for Indian Projects
Indian public tenders commonly ask for the documents below. State which ones your tender requires when you send the enquiry, so they are covered in the quotation.
- Manufacturer / OEM authorisation
- Country of origin and local-content declaration (for Make in India purchase preference)
- Type-test and routine-test certificates, and the FAA / ICAO / IEC compliance documents named in the specification
- Datasheets, drawings and installation instructions
- Warranty, delivery period and spares support
- GeM catalogue or tender-portal requirements, where applicable
Request CCR Technical Data and Circuit Compatibility Review
Planning a new AGL series circuit or replacing an existing constant current regulator? Provide the circuit current, input voltage, lighting load, intensity-step requirements and control arrangement, plus the existing CCR nameplate and series-circuit details where available. We can evaluate the regulator configuration against the associated AGL circuit and project requirements.
Engineering Note
Ferroresonant CCR ratings, output characteristics, intensity steps, control interfaces, protection functions and cooling requirements are configuration-dependent. Final equipment selection should be verified against the complete series-circuit design, connected load, airport control requirements and applicable project standards before procurement.
Product Disclaimer
Product availability, configuration, dimensions, electrical characteristics, photometric performance, certifications and compliance status depend on the selected manufacturer and project specification. The technical values published on this page should not be treated as a substitute for the manufacturer's current approved Technical Data Sheet.
Final selection shall be based on the approved project specification, applicable aviation standards, authority requirements, manufacturer documentation and site conditions. Use of this page is also subject to the Legal Notice, Disclaimer & Terms of Use.
Standards and editions referenced on this site are listed on the Standards Reference page.