How to choose the right UPS battery back-up for network closets and IDF applications​

Network cabinets and intermediate distribution frames (IDF) are critical parts of IT  networks, but they’re often scattered about. They seldom have dedicated IT personnel close by and are often neglected. A network cabinet can be a lonely place! And yet if there’s a power cut, an IDF or network cabinet being knocked out of commission can cause significant problems. They’re also vulnerable to both non-IT humans (e.g. the cleaning staff unplugging the UPS battery back-up) and cybersecurity breaches. ​

Selecting the right UPS battery back-up for your network cabinet or IDF can be a confusing process. This uninterruptible power supply (UPS) buying guide is designed to help you properly plan so you can make your IT network more resilient and reliable.

Let’s get started with these ten buying tips to help you select the right UPS battery back-up.​

1) Consider the right UPS battery back-up form factors for your network cabinet ​

An uninterruptible power supply (UPS) form factor isn’t complicated – it’s simply how the UPS is shaped. ​

  • Rack-mount UPSs are measured in U, which is equivalent to 1.75 inches of vertical rack space. Rack-mount UPSs typically come in 1U or 2U models, though some larger models are 3U. The good news with rack-mount UPSs is that they slide in alongside your IT equipment, off the floor, away from water leaks and spills. Be sure that the proper 2 or 4-post mounting hardware is included with the UPS battery back-up or you’ll need to purchase it separately. When it comes to installing the UPS, it's almost always the heaviest component in your rack so you'll want to position it at the bottom especially if you have external battery packs.​

See Eaton’s rack-mount UPS solutions ​

  • Wall-mount UPSs are often deployed when there’s no existing UPS or only limited available space to add to the IT rack. Placing a UPS battery back-up on the wall limits access to it, which is a good thing! You’ll need to make sure that you mount the UPS to the wall so that it’s stable. You can also install a UPS inside of a wall-mount rack enclosure, such as the MiniRaQ by Eaton. Due to their lighter weight, UPS models with lithium-ion batteries are a good choice.  ​

See Eaton’s wall-mount UPS solutions

  • Tower UPSs are shaped like toasters – they’re just a lot heavier! Tower models are ideal for desktop applications, and placing a UPS battery back-up on the floor is often less than ideal, as you never know when there will be a water leak or a spill of some sort. There’s also the possibility of someone kicking it or accidentally unplugging it. If there’s room, you can place a tower UPS on a shelf in a 2 or 4-post rack to avoid these issues. The good news with tower UPS models is that they often cost less than their rack-mount counterparts.​

See Eaton’s tower UPS solutions


2) Consider your battery runtime needs​

The most common questions about a UPS battery back-up are related to pricing and how long the batteries will last during a power outage. UPS batteries are heavy (though lithium-ion batteries are about 40% lighter than lead-acid ones) and extra battery packs can quickly increase costs. Most power interruptions are short – less than two minutes – so users usually look for approximately seven to ten minutes of battery runtime. As a general rule, when you cut the load (equipment plugged into the UPS system) in half, you triple the runtime. For example, if your 1500 VA UPS lasts for five minutes at full load, it will run for approximately 15 minutes if you cut the load down to 750 VA. For Eaton UPS runtimes, check out our comprehensive battery times page

​In addition to adding battery packs to a UPS, another common practice is to combine the immediate power back-up of a UPS with the long-term power of a generator. Eaton has several UPSs that are designed to pair with a generator.

3) Determine the right UPS battery back-up wattage

First add up the wattage of all the equipment you plan to connect to the UPS and then multiply the total by 1.2 to account for future expansion. With this grand total in watts, you can find a UPS that has enough power capacity. ​

A UPS battery back-up is rated in volt-amperes (VA) and watts. Watts is a measurement of real power and is the key rating. However, it’s easy to be fooled by VA ratings. For example, a UPS rated at 1000 VA/900 watts provides one third more power than one rated at 1000 VA/600 watts, even though at first glance it appears that they have the same power rating. Find out more about the difference between watts and VA.


Find the right UPS to back up your equipment (up to 6 kVA)

4) Choose UPS battery back-up input plug and facility site voltage​

Once you’ve determined the wattage that your UPS battery back-up needs to support, you can look at UPS models with an adequate power rating. In North America, the standard wall socket is called a 5-15R. UPS models 1500 VA and below use a matching 5-15P input plug rated at 15 amps. Some sites may have a 5-20R as the standard, which can accommodate both 5-15P and 5-20P UPS input plugs. If you want a larger UPS system and don’t have a 20 or 30-amp wall socket, you’ll need to get an electrician to install the right socket. Take a look at this UPS connections overview for more details and pictures.
In North America, the typical office socket delivers 120V and convenience is the main benefit. Simply plug in the uninterruptible power supply and you’re ready to go. While it is the most convenient approach, your load requirements may exceed what you can do with 120V. It’s also possible to deploy a 120/208V split-phase UPS like the Eaton 9PX. Using 208V single-phase power is an even more energy-efficient solution,​

Ask Ed: White-space 208V UPS configurations

Ed Spears answers a question about UPS end-of-row configuration in the white space.

Follow these considerations to:

  • Simplify installation
  • Enhance efficiency
  • Become a more scalable and redundant data centre

5) Make sure your UPS battery back-up has enough output sockets​

Making sure that your UPS battery back-up has enough output sockets so you can plug in all of your equipment is very important. 

If you are short on output sockets, don’t worry! One option for adding additional outlets is the Eaton FlexPDU, which is a basic-function power distribution unit with a short power cable for easy, close mounting to a UPS system. FlexPDUs are available with a variety of output sockets for connection to a wide range of equipment. For example, the EFXL1500R-PDU1U has (12) 5-15R outlets. ​


6) Protect servers with a sine wave UPS​

The waveform of electrical power (AC) is a sine wave. However, some UPS battery back-up models provide a modified or square wave output while they’re running on battery power. If you’re protecting servers, you should use a true sine wave UPS. Standby UPS or offline UPS models are the most common types that don’t provide pure sine wave output. Line-interactive and online UPSs almost always deliver a pure sine wave, but you should always read the technical specifications to verify this. ​

7) Consider monitoring, alerts and automation​

Network cabinets and IDFs are typically remote, seldom occupied by IT staff and often neglected. The audible alarm of a UPS battery back-up is useless if no one is there to hear it. However, by incorporating monitoring and alert notifications you can be notified and take action if necessary. Depending on the scope of your application, there are four possible solutions:

1. Single UPS system: network card​

You can usually monitor a single UPS battery back-up through an optional network card. Eaton network cards are essentially their own servers, so they record event history, send email and text message alerts and provide remote access to real-time status. Using a network card is usually the best way to manage a single UPS system.

Check out this review for a glimpse of what you can do with a UPS network card.

The latest Eaton UPS network card is the first to meet UL and IEC cybersecurity standards, provides a Gigabit Ethernet connection and enables secure UPS monitoring over HTTPS web browser interface, SNMP v1/v3 protocol and email alarms.​

2. Multiple UPS installations: network cards and Intelligent Power Manager (IPM) or Visual Power Manager (VPM) 

For multiple UPS systems spread out across a network cabinet, campus or enterprise, IPM aggregates and manages your power devices (both UPSs and network-enabled rack PDU products). IPM can even trigger air gaps to improve network security.​

3. Virtualisation: network card and IPM​

IPM is the industry leader in integrating power with a virtualisation platform. The IPM shutdown agent management enables the safe shutdown of virtualised servers – even servers in clusters, running vCenter. Live migrations can be triggered to transparently move virtual machines to an available server on the network for data integrity and zero downtime.​


8) Choose a UPS battery back-up with comprehensive warranty and service cover

When comparing uninterruptible power supply models, be sure to check the warranty, like this 3-year warranty on the Eaton 5 series UPS models.

  • How long does it last? 
  • Does it cover both the UPS and its batteries? Is delivery included? 
  • Are the batteries user-replaceable?​

Most network cabinet UPS models are plug-and-play, and you can take advantage of extended warranties and advance exchange plans where a replacement UPS is delivered to you as soon as you notify the manufacturer that you need a replacement. ​

9) Consider UPS maintenance bypass and redundancy

Redundant Eaton 9PX UPS with Eaton eATS. Photo courtesy of All Green Lights, LLC 

Depending on your budget, you can both increase the reliability of your system and make your life easier down the road. Adding a maintenance bypass allows you to service or replace the UPS battery back-up without shutting down the connected equipment. ​

An Eaton automatic transfer switch (ATS) PDU is an ideal fit with the Eaton 9PX UPS. The ATS automatically transfers power between sources with no interruption if the primary source fails or requires maintenance to eliminate equipment downtime.

Take a closer look at these UPS maintenance bypass best practice designs.

Interact with a network cabinet

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10) Think beyond your UPS

Finally, for a well-rounded solution you can add a temperature and humidity probe.  ​

If you’re managing a fleet of uninterruptible power supplies, a remote monitoring service like PredictPulse could be a great option for you. PredictPulse monitors your power devices and alerts Eaton personnel who can promptly deploy an Eaton field technician to the affected site. 

Read about a leading retailer with over 300 stores who was constantly having battery and service issues until Eaton provided a comprehensive solution.​