Leaving a single stockroom light on for 24 hours may not seem like a big expense. But if several lights are left on for several days running, the costs can add up.

Mount Vernon, N.Y.-based Tork has developed the SSA100, an interval timer, to save the energy wasted when people forget to turn off lights, fans, etc. The unit's function is similar to the timer knob on a hotel heating lamp -- except that a time interval has been pre-set -- with time ticking down before the unit shuts off , says Elliot Mintzer, marketing services manager for Tork. Hotels install these timers so guests can't leave the heat lamps on all day. The retail industry can save similarly in areas like stockrooms and maintenance closets.

If employees come into these areas armed with one of these timers, there's no way they can waste the center's energy by walking out and leaving the light on.

The timer offers eight field settings ranging from 5 minutes up to 12 hours. Once the wallplate is installed, the unit becomes tamper-resistant -- the plate must be removed to reset the unit. "The person who installs it determines how long they want the lights to stay on," Mintzer says.

Instead of leaving people in the dark, the unit, like a football game, offers a two-minute warning. Two minutes before the lights shut off, the unit beeps and/or flashes the lights in the room. At that point, the timer's switch can be hit again and the pre-set time will start over.

The countdown is displayed on an illuminated screen, making it visible with the lights on or off.

Mechanicals The timer can replace a basic wall switch in only a few minutes in either a single or multiple gang wallbox. The timer is compatible with electronic ballasts or can control incandescent lighting or motor loads, i.e., ventilating fans.

It accepts dual voltage input of 120 VAC or 277 VAC, 60 Hz. Contacts are rated up to 800 watts at 120 VAC or 1,200 watts at 277 VAC. No minimum load is required.

Time can be set for 5 minutes, 15 minutes, 30 minutes, 1 hour, 3 hours, 6 hours, 9 hours or 12 hours.