Follow Applicable Industry Standards - Extreme Networks 8820 Hardware Installation Manual

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Table Of Contents

Table of Contents

Site Preparation

•

Where will the UPS be installed?

•

What is the maximum transition time that the installation will allow? (See

Transition Time

Note

We recommend that you use a UPS that provides online protection.

Calculate Volt-Amperage Requirements

About This Task

To determine the size of UPS that you need:

Procedure

1. Locate the voltage and amperage requirements for each piece of equipment.

These numbers are usually found on a sticker on the back or bottom of your equipment.

2. Multiply the numbers together to get Volt-Amperes (VA):

VA = Volts x Amperes

3. 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, we recommend that you add

30% to the total.

Provide a Suitable UPS Transition Time

UPS transition time is the time required for the UPS to change from providing AC power derived from

the utility (or mains) supply to providing AC power derived from the battery backup. UPS transition

time is sometimes called UPS transfer time.

UPS transition times vary between UPS models and implementations, but shorter transition times

are preferred. For Extreme Networks stacking products, we recommend a UPS transition time of 20

milliseconds or less to ensure optimum performance and minimize service interruptions.

For high-availability and fault-tolerant installations in which the switches use redundant power supply

units (PSUs), we recommend that each PSU in a switch be connected to a different UPS and that each

UPS be powered by an independent AC supply. This will prevent service interruptions when a power

source is lost, or when a UPS unit fails. (Note that a single, appropriately sized UPS can power PSUs

in multiple switches. The recommendation is simply that for any given switch, the two PSUs should be

connected to different UPS units.)