What are CCR intensity steps?
The fixed brightness settings of a constant current regulator, each one a set output current that changes how brightly every light on the circuit burns.
A constant current regulator does not dim smoothly. It offers a small number of fixed intensity steps, usually three or five. Each step makes the CCR drive a specific rated output current through the series circuit, and because the same current flows through every light on the circuit, all fixtures change brightness together.
Light output is not proportional to current: a halogen lamp gives far less light at lower current, and an LED fixture is designed so that each step current gives its intended intensity, so the low steps are far dimmer than the current ratios suggest. The step is chosen from the tower or control system, or locally at the CCR, to suit daylight, dusk, night or low-visibility conditions. Each step is checked by measuring the real output current against its rated value and tolerance.
- Assess conditions. Daylight, dusk, night or reduced visibility sets the brightness needed.
- Select a step. Choose it from the tower or control system, or at the CCR in local mode.
- CCR sets current. It regulates the output to the rated current for that step.
- Current flows in series. The same current passes through every transformer and light on the circuit.
- Brightness changes. All fixtures on the circuit step up or down together.
- Verify. Measure output current at each step against the rated value and tolerance.
Frequently Asked Questions
Q1What are CCR intensity steps?
The fixed brightness settings of a constant current regulator. Each step makes the CCR deliver a set output current to the series circuit, and that current determines how brightly the lights burn.
Q2How many intensity steps does a CCR have?
Commonly three or five, depending on the CCR type and the lighting requirement. Each step has its own rated current, and the highest step uses the CCR full rated current.
Q3Why is brightness not proportional to current?
A halogen lamp gives disproportionately less light as current falls, and an LED fixture is designed so that each step current gives its intended intensity, so the lower steps are much dimmer than the current ratios suggest. The step currents are chosen to give the intended spacing of light output.
Q4Who selects the step?
The step is chosen from the tower panel or control system, or locally at the CCR, depending on the mode. It is normally set for the conditions, such as daylight, dusk, night or low visibility, under the airport’s procedures.
Q5Why use fixed steps instead of continuous dimming?
Fixed steps give defined, repeatable brightness levels that match the intensity settings the lighting is designed and certified for, and they let every fixture on the circuit change together by a known amount.
Q6How are intensity steps verified?
By measuring the CCR output current at each step with a calibrated true-RMS meter and comparing it with the rated value and tolerance, as part of CCR testing and maintenance.
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