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L2-3

Power Variation

It is important to understand the technical terms for the various undervoltage and overvoltage conditions that could exist, such as power surge, dirty power, sag, brownout, and blackout, as well as the device that provides protection to the computers and computer system equipment when these conditions occur. A power surge occurs when a short increase in AC voltage happens, such as from 120 VAC to 130 VAC. To protect computers from this condition, you would use a surge suppressor. Dirty power occurs when AC voltage continuously fluctuates, for example between 113 VAC and 130 VAC. To correct this condition, an in-line UPS or line conditioner should be used. A sag occurs when an unexpected short decrease in voltage occurs. This can be corrected with either a line conditioner or a UPS. A brownout is a more significant, larger voltage drop than a sag, and could result in the voltage being cut in half (such as 120 VAC dropping to 60 VAC). This is too much for a line conditioner to handle, so a UPS would be required. Finally, if there is a complete loss of power, this is called a blackout. Only a UPS can solve this problem, but only for a short duration (purportedly about 15 minutes). If operations must continue after this, you would need to switch to a backup generator to provide the power required.

重要的是要理解可能存在的各種欠壓和過壓條件的技術術語，例如電湧，臟電源，跌落，掉電和停電，以及在以下情況下為計算機和計算機系統設備提供保護的設備：這些情況發生。當交流電壓短暫升高時（例如從120 VAC增加到130 VAC），就會發生電湧。為了保護計算機免受這種情況的影響，應使用電湧抑制器。當交流電壓持續波動（例如在113 VAC和130 VAC之間）時，會產生臟電。要糾正這種情況，應使用串聯式UPS或線路調節器。當電壓出現意外的短時下降時，就會發生下垂。可以使用電源調節器或UPS進行糾正。掉電比下垂更為顯著，更大的電壓降，並且可能導致電壓降低一半（例如120 VAC降至60 VAC）。對於線路調節器來說，這太多了，因此需要UPS。最後，如果完全斷電，則稱為停電。只有UPS可以解決此問題，但只能持續很短的時間（據說大約15分鐘）。如果此後必須繼續操作，則需要切換到備用發電機以提供所需的電源。

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