Nowadays, electrical and electronic equipments play important roles and widely used in our daily lives. Most of those equipments are power sensitive. Thus, it is quite difficult to avoid the effects of the power problems such as system breaks down or fails which may caused the loss of data, information and OPPORTUNITIES. To understand the causes and effects of power problems will help you to prepare to defend the problems and protect the system from the uncertainty of power. Sag or Brownout Sags are short duration decreases in voltage of electrical power line. Sags are the most common power problem recognized when local lighting "dim". Cause: Sags can be created by turning on large inductive electrical machines (including motors, water pumps, air conditioners, elevators, tools, etc.). Because these machines consume extra power demand when start up. Effect: A sag can cause your computer hang up and damage, as well as lost data. Sags also decrease the efficiency and shorten life span of electrical appliances, especially motors. Remark: Sine Wave describes a graphical representation of the supply voltage and frequency present in a normal utility power. Blackout Blackouts describe total loss of utility power. Cause: Blackouts are caused by excessive demand on electrical power grid, short circuit on power line, lightning, earthquakes, accidents with power distribution network. Effect: The current work in RAM or cache is interrupted this can cause lost data. The hard drive File Allocation Table (FAT) may also be lost, which results in total loss of data stored on drive. Spike Spikes are instantaneous increase in voltage. A spike can enter electronic equipments through power grid, network and phone line. Cause: Spikes can be caused by such things as a nearby lightning strike or when utility power comes back on line after failure. Effect: Spikes can cause damage to your computer, modem as well as other components. Inclusively data will be lost. Surge Surges are sudden transient increase in voltage (1/120 of a second). Cause: Surges are commonly created by immediate reduction of consuming electrical power on large local electrical machines (air conditioners, refrigerators and similar electrical machines). Because the extra power that these machines were using is then released back into the utility lines. Effect: Surges can cause premature failure or damage of critical components. The memory may also be lost, data error, power supply lost and communication system malfunction. Noise Noise is high frequency Electro-Magnetic Interference (EMI) or Radio Frequency Interference (RFI) induced or coupling into power line. Noise interferes the smooth of sine wave expected from power line. Cause: Electrical noise can be caused by lightning strike, load switching, radio transmitters, office equipments and industrial equipments. Noise may be intermittent or permanent. Effect: Noise introduces glitches and errors into executable programs and data files.