All HID lamps require less power to burn than to start.
Full power is supplied only when the lights are first turned on.
Wattman actually reduces the amount of electricity that flows from a lighting panel to individual lamps. The lamp will continue to emanate light at this lower voltage, thus saving energy and money with no perceptible loss of light. Savings will depend on the hours of operation of the facility. The most savings will be achieved in applications where Wattman TM can save up to 24 hours per day. If portions of the lighting circuit are turned on at various times, Wattman TM senses this using its downline switching capability.