|  | 8.10 | Network Power Supply Issues: Power Line Problems
| 8.10.7 | Sag and brownout solutions
While surge suppressors can help resolve problems presented by sags and spikes, they cannot prevent the occurrence of sags and brownouts. A drop in AC power may cause only the faintest flicker of your electric lights; however, the same drop in power can be devastating to your data. This is especially true if you happen to be updating a file directory when a power failure occurs. Such a brownout could cause the directory, all subdirectories, and files along its path, to be lost. While the threat of power outages can be minimized by keeping current backups of all data, this measure will not prevent the loss of working files that are open on network computers. Every network should have some type of uninterruptable power supply.