What is circuit status?
The reported state of a lighting circuit — measured at the CCR and shown at the display and the control room, so a fault is seen before it is found on the ground.
Circuit status is the state of a series lighting circuit as the CCR sees it. The controller measures the output current, output voltage and earth leakage, compares them with set limits, and reports whether the circuit is normal or has an open circuit, short circuit or earth fault.
The status appears on the CCR’s own display and is sent to the control and monitoring system so operators can see it remotely. This matters most for faults that do not put the lights out: an earth fault usually leaves the loop closed and the lights on, so only the status reveals it. A second earth fault elsewhere can short out part of the circuit, so a first fault should be found and cleared early. A short circuit darkens only the lights in the shorted section, and because the CCR holds the current constant it shows mainly as a fall in output voltage.
- Measure. Sensors read current, voltage and leakage to earth.
- Compare. The controller checks the readings against its limits.
- Indicate. The state is shown locally and passed to the remote control system.
Frequently Asked Questions
Q1What is circuit status?
The reported state of a series lighting circuit: whether it is on or off, at what brightness step, and whether it is healthy or has a fault such as an open circuit, short circuit or earth fault.
Q2What does the CCR measure to work out status?
Typically the output current, the output voltage and the leakage to earth. The controller compares these with set limits and decides which state the circuit is in.
Q3Where is circuit status shown?
Locally on the CCR display and, through its remote interface, at the control and monitoring system (ALCMS) in the tower or control room, so operators see the true state without going to the field.
Q4Why can an earth fault go unnoticed without status monitoring?
The loop stays closed, so the lights usually stay on. Only the leakage measurement reveals it, which is why status monitoring matters for faults that do not switch the lights off.
Q5How does an open circuit show up?
The loop is broken, so no current flows and the whole circuit goes dark. The status shows no loop current and the CCR protection normally shuts the output down.
Q6Is the status the same as a lamp being on?
No. Lights being on only shows that current is flowing. Status also reports whether that current is at the correct value and whether the insulation to earth is still healthy.
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