Uninterruptible Power Supply Requirements; Selecting A Ups; Calculating Volt-Amperage Requirements - Extreme Networks Summit X450a-24tDC Hardware Installation Manual

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.
A UPS traditionally can perform the following functions:
Absorb relatively small power surges.
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Smooth out noisy power sources.
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Continue to provide power to equipment during line sags.
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Provide power for a period of time after a blackout has occurred.
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In addition, some UPS devices or UPS-plus-software combinations provide the following functions:
Automatically shut down equipment during long power outages.
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Monitor and log power supply status.
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Display the voltage (current draw) of the equipment.
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Restart equipment after a long power outage.
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Display the voltage currently on the line.
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Provide alarms on certain error conditions.
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Provide short-circuit protection.
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Selecting a UPS

To determine UPS requirements for your switch, answer these questions:
What are the amperage requirements?
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What is the longest potential time period that the UPS would be required to supply backup power?
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Where will the UPS be installed?
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What is the maximum transition time that the installation will allow? (See
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page 78)
NOTE
Extreme Networks recommends that you use a UPS that provides online protection.

Calculating Volt-Amperage Requirements

To determine the size of UPS that you need:
1 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 Volt-Amperes (VA):
VA = Volts x Amperes
2 Add the VA from all the pieces of equipment together to find the total VA requirement.
To determine the minimum volt-amperage requirements for your UPS, Extreme Networks
recommends that you add 30% to the total.
Summit Family Switches Hardware Installation Guide
Meeting Power Requirements
"UPS Transition Time" on
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