Failures in the mains or a deficient quality of the provided current can no longer bring about failures in the computer science equipment only at component level hardware spoiling but at software level causing loss of information (corrupt files). In order to avoid this type of errors and to prevent a fast aging with the components the Systems of Uninterrupted Feeding can be used, SAIs (in English UPS – Uninterrumpible Power Supply). These apparatuses that usually are made up of batteries, a shipper and an undulator to turn DC into alternating have the mission to improve the quality of the electrical energy before problems happened in the network. Basically usually they study two aspects before acquiring a SAI: Required power and autonomy. The SAIs is preparations to equip to the system an amount with energy during a certain time. Usually they use as measured the power pretends consumed Volt-Ampere (IT GOES) whose relation with the consumed real power in watios (w) is the following one: w = 0.6 xs GOES.

The consumption of a basic equipment will depend on the components that it has connected (power supply, motherboard, microprocessor, memories, hard disks, etc) but basically a tower in rest can consume about 160 watios and about 300 to total yield. I repeat that this consumption will vary based on the components and of the use that is occurring these. The total consumption will come from the sum of the one of the tower, monitors, peripheral, etc. Is very important to know that devices will be connected to the SAI to know the power that must provide and during how long since no of the values (neither watios, IT GOES nor them) can be exceeded by the consumption. The time of autonomy would have to be the sufficient one to close everything what it is becoming and to extinguish the equipment with normality. .