Extreme Networks BlackDiamond 8810, Hardware Installation Manual

Page: 152 / 162

Safety Information
Extreme Networks Consolidated XOS Hardware Installation Guide
152
Uninterruptible Power Supply Requirements
An uninterruptible power supply (UPS) is a device that sits between a power supply (such as a wall
outlet) and a device (such as a switch) to prevent outages, sags, surges, and bad harmonics from
adversely affecting the performance of the device.
UPS Features
A UPS traditionally can perform the following functions:
●
Absorb relatively small power surges.
●
Smooth out noisy power sources.
●
Continue to provide power to equipment during line sags.
●
Provide power for some time after a blackout has occurred.
In addition, some UPS or UPS plus software combinations provide the following functions:
●
Automatically shut down equipment during long power outages.
●
Monitor and log power supply status.
●
Display the voltage (current draw) of the equipment.
●
Restart equipment after a long power outage.
●
Display the voltage currently on the line.
●
Provide alarms on certain error conditions.
●
Provide short circuit protection.
Calculating Amperage Requirements
To determine the size of UPS that you need, use the following procedure:
1 To find Volt-Amps (VA), locate the voltage and amperage requirements for each piece of equipment.
These numbers are usually located on a sticker on the back or bottom of your equipment. Then
multiply the numbers together to get VA:
VA = Volts x Amperes
2 Add the VA from each piece of equipment together to find the total VA requirement.
To determine the minimum amperage requirements for your UPS, we recommend that you add 30%
to the total.
UPS Transition Time
Transition time is the time that is necessary for the UPS to transfer from utility power to full-load
battery power. For Extreme Networks products, a transition time of less than 20 milliseconds is required
for optimum performance.