Uninterruptible power supply (UPS)

• Is placed between the electrical receptacle and your computer or other electronic piece of equipment.
• Isolates your equipment from an outage.
• The UPS device switches to battery backup when the unit senses a power outage or change in voltage.
• Gives you time to save information and shut down your equipment.

MGE recommendations

• Use a UPS with any piece of electronic equipment that could be adversely affected by power problems. These include PCs, phone systems, etc.
• If a piece of computer equipment is critical, choose an on-line UPS.
• For less critical equipment, choose a standby or line-interactive UPS.

UPS types
Standby or off-line UPS allows house power to flow to electronic loads until it detects a change in voltage or a power outage, then switches the load from the incoming line to internal batteries. Check to make sure your computer can tolerate the switching time needed to transfer from the incoming line to the internal batteries.

Line-interactive

• Features an internal circuit that attempts to maintain normal voltage levels.
• Regulates the voltage without resorting to battery power.
• Helps the batteries last longer.
• Assures batteries are only used during a power outage.

On-line

• Powers the computer or other equipment from an internal power supply 100% of the time.
• AC power from the incoming line is converted to DC, converted back to AC and then fed to the computer.
• Incoming power is continually filtered and recreated.
• Provides the highest level of protection.

For more information
How to Protect Your Computer from Power Outages [PDF - 384 KB]