Site Preparation
UPS Features
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 some time after a blackout has occurred.
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In addition, some UPS 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, ask 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 your installation will allow?
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NOTE
Extreme Networks recommends that you use a UPS that provides online protection.
Calculating 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-Amps (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.
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Extreme Networks Consolidated ExtremeXOS Hardware Installation Guide