Circuits and Supply – 5 minutes
Describes a basic series lighting circuit. Uses Ohm‘s Law and animated diagrams to show how a constant current transformer adjusts its output voltage to keep a fixed current flowing into a changing load.
Control Devices – 10 minutes
Shows how a primary oil switch opens and closes the current flow to the primary side of a transformer. Describes photocells and time switches, and demonstrates how they operate. Explains how special relay-type devices are used in street lighting circuits.
Series Systems, Part 1 – 10 minutes
Describes series street lighting systems where lamps and components are connected directly to a constant current transformer secondary. Explains how an incandescent lamp operates, and how a high-voltage head (socket) keeps other lights on when one lamp in the string burns out.
Series Systems, Part 2 – 11 minutes
Describes lighting systems where the lamps are connected through auxiliary isolating transformers. Explains how an isolating transformer works. Shows the parts of a mercury vapor lamp. Using simple schematic diagrams, shows how these components are connected in series lighting systems.
Maintenance and Troubleshooting, Part 1 – 8 minutes
Describes two common maintenance procedures: re-lamping a fixture, and replacing a faulty isolating transformer.
Maintenance and Troubleshooting, Part 2 – 13 minutes
Describes troubleshooting techniques for common problems that can occur in series street lighting systems. Solves two typical field problems by sectionalizing the circuit to locate the problem.