Setting up an AC single rail track circuit requires equipment that supports the single rail design, where only one rail is insulated and the other rail remains continuous.
Insulated rail joints are installed on only one of the two running rails. These joints electrically isolate the track block from adjacent sections and define the limits of the track circuit.
The AC power source, usually a transformer or oscillator, supplies the alternating current signal to the track circuit. The voltage and frequency must match the requirements of the receiver.
The AC receiver may be an AC-sensitive relay or electronic detection unit. It detects whether the proper AC signal is present or absent and changes state when a train shunts the circuit.
Connecting wires and cables connect the power source and receiver to the insulated rail and the continuous rail. Proper wire size, insulation, and secure connections are important for reliable operation.
Bonding straps may be used to maintain good electrical continuity of the continuous rail. Test and calibration equipment such as multimeters, oscilloscopes, and shunt testing devices are used to verify the circuit operates correctly.