Power dips are temporary fluctuations in the voltage of an electric system. They occur most frequently in home electrical systems, and are typically triggered by the presence of a substantial increase in load on the circuit. Under ordinary circumstances, power dips are not a threat to most appliances and other electronic devices; however, they can affect particularly sensitive pieces of electrical equipment. Potential damage from changes in voltage can be minimized by a using an uninterruptable power supply.
One of the most common situations in which power dips occur is when an individual adds a high-current electric item to an already loaded circuit. By plugging in and running a device like a microwave or hair dryer, the added stress on the circuit results in a temporary dip in the amount of available power. As a result, the lights in the house may dim, devices on the same circuit may stutter momentarily, or other temporary electrical phenomenon may occur.
![](http://images.aboutmechanics.com/slideshow-mobile-small/electricity-wires.jpg)
Under normal conditions, the symptoms caused by power dips should not last more than a few seconds, after which the circuit should become used to the additional demands placed upon it by the high-current device. This will typically have no adverse effect on most electrical items, such as lights, refrigerators, stoves, and other appliances. More sensitive devices like computers — especially high-powered computers, mainframes, and servers — can potentially suffer as a result of power dips, however. The momentary lapse in power could potentially cause the system to crash, force the computer to reboot, interrupt a computer network, and potentially trigger some data loss in active programs.
The easiest way for a person to prevent power dips from affecting sensitive electronic devices is to use an uninterruptable power supply (UPS). A UPS is designed to absorb fluctuations in the amount of available current on a line, providing the device to which it is connected with a steady, unbroken flow of electricity. Any computer that contains important business or personal data, or which performs critical functions that could be disrupted by a power dip, can benefit greatly from being attached to a UPS as a precaution against potential damage to the hardware or the information stored on the computer.