Facilities Management

Unplanned Outages

Section 1

Facilities Management is committed to providing the campus with reliable electricity service. Electricity is supplied to the campus from a variety of sources: UCI's central generation plant, Southern California Edison (SCE) and solar. An underground high voltage grid internal to the campus distributes electricity to the buildings.

While electrical service reliability in our area is above average, unplanned outages do occur and it is important to prepare. Keeping informed and prepared can help minimize the impacts of an unplanned outage.


What Causes Unplanned Power Outages?

Common causes nationally and locally are:

  • weather (high winds, storms, lightning)
  • high electrical demand
  • animals contacting wires
  • equipment failures
  • vehicle accidents damaging poles or other equipment

Common causes at UC Irvine are:

  • failed campus cables
  • failure of SCE service
  • flooding
  • other unpredictable events (earthquakes)

Common Misconceptions:

  • Emergency outlets are uninterruptible power
  • Insurance will cover losses
  • If an outlet is open, the circuit must be available

 What Should I Do Prior to an Outage to Protect Electrical Equipment?

  • Install Uninterruptible Power Supplies (UPS) to create a "ride-through" capacity (see next section for details).
  • House critical computers in centralized data centers, as appropriate. Contact OIT at (949) 824-2222 for further information.
  • Install UL 1449 standard rated surge protectors. Computers can be damaged, not only from electrical surges and spikes, but as well as flickering, especially during bad weather. Surge protectors help protect equipment from these occurrences.
  • Surge protectors sometimes aren't enough to protect computers, therefore it may be wise to protect your computer system with a UPS. The campus recommends several UPS systems:

Selecting a UPS

  • For more information on selecting a UPS see: Selecting a UPS
  • For more information about UPS see: Scheduled Power Outages
  • For assistance with determining appropriate systems specifications, call Facilities Management at (949) 824-5444.
  • If you building has emergency generators with back-up circuit power, plug critical equipment into designated electrical outlets. This will provide emergency power from emergency generators. There is only limited power available from these emergency power sources. Please connect only the most essential equipment to these circuits. Even with emergency electricity supply, you will experience a brief service outage until the emergency generator starts and the transfer switch connects the generator to the system. See the section on "Ride-through" if you need uninterrupted power.

To stay informed about planned utility outages, subscribe to our outage notification list (UCINetID is required).

Understanding "Ride-Through" and What I Should Do Prior to an Outage to Protect Sensitive Electrical Research Equipment

  • Most campus unplanned power outages last a few minutes to a few hours.
  • A UPS can be used to support sensitive research equipment during an electricity service outage.
    • For buildings with emergency generators with back-up circuits for equipment, plan to "ride-through" from the time primary electricity service is lost, until the standby generator starts and connects to the serve the load. This will be about 10 seconds after a full power outage.
      • Because the standby generators sometimes fail to start, size and select a UPS to give time for an orderly shutdown.
      • For buildings without standby generators for laboratory equipment, a properly sized UPS should allow orderly shutdown of sensitive equipment.
  • Check with your equipment manufacturer to get their recommendation for the type and size of UPS for your system.
  • If your building has emergency generators with back-up circuit power, plug critical equipment into designated electrical outlets. This will provide emergency power from emergency generators. There is only limited power available from these emergency power sources. Please connect only the most essential equipment to these circuits.
  • For research freezers and similar equipment, it is also recommended that alarm systems be used to automatically contact you in the event of a power interruption.

Campus Assistance for Purchasing UPSs for Critical Electrical Equipment

UCI is identifying a source of funds to offset 50% of your UPS or freezer alarm costs if you purchase a campus recommended UPS or research equipment manufacturer recommended device for qualifying research equipment. Maintenance of these specialized systems is the responsibility of the researcher.

What Preventative Measures Has UCI Taken?

To minimize the impacts of power outages on the UC Irvine community:

  • Buildings have emergency exit lighting to assist you in locating exits.
  • All exit doors will continue to function during a power outage.
  • In some buildings, emergency generators and transfer switches will provide back-up electricity during an outage. Facilities Management staff test and maintain these generators and transfer switches on a regular basis to help ensure they will perform as expected in outage situations.
  • OIT has installed equipment in their data centers to help protect critical networked servers and computers.
  • Facilities Management uses available resources to repair, improve, and expand the campus electrical infrastructure, making the campus electricity service more reliable.

What Else Can I Do to Prepare for an Unplanned Power Outage?

 To make power outages safer and less inconvenient you can:

  • Keep a flash light and spare batteries in a handy location. Check them regularly.
  • If you use a computer, back-up files and operating systems regularly.

Preparing for Unplanned Power Outages in a Lab

Develop an emergency plan specifically for your lab and inform anyone occupying your lab of their responsibilities.

  • Shut down experiments that involve hazardous materials.
  • Make sure experiments are stable and won't create uncontrolled hazards.
  • Check fume hoods and biosafety cabinets and take the following precautions, if applicable:
    • Stop any operations that may be emitting hazardous vapors, fumes, or infectious agents.
    • Securely cap any open containers.
    • Close fume hood and biosafety cabinet sashes.
  • Check equipment on emergency power to ensure it's running properly.
    • Note: It may take 20 to 30 seconds for emergency power to activate after a power failure.
  • Reduce electrical use and risk of power surges by:
    • Disconnecting from emergency outlets equipment that runs unattended, and
    • Turning off unnecessary lights and equipment.

What Actions Are Taken By the Campus When an Unplanned Outage Occurs?

Minimizing the impact of an electricity service outage on the campus community is a top priority. Facilities Management is staffed 24/7 and immediately responds to outages by identifying the problem, informing the campus community, and working to restore service safely and as quickly as possible.

Sources of Power Outage Information

Depending on the situation, some or all of these sources may have information about the outage:

  • Campus Emergency Status and Conditions, 24 hours a day: 866-IRV-NEWS (866-478-6397)
  • The UCI Communications homepage will have links to campus emergency conditions: http://communications.uci.edu/campus-resources/preparedness.php
  • Facilities Management's Campus Service Disruptions / Outage Notification information.zotAlert Emergency Alert System uses cell phone text messaging to quickly notify the campus with emergency and safety related information. To learn more or to sign up, visit: http://www.oit.uci.edu/zotalert/
  • WQTB 1690 AM / Zot Radio
  • KUCI Radio Station
  • UCI PD Emergency Updates and Preparedness Information: Nixle
  • Southern California Edison Customer Service: 1-800-655-4555 / Outage Center: 1-800-611-1911
  • Information sign boards may be posted around campus.
  • Email messages may be sent out to all students, staff, and faculty.
  • News releases may be distributed by local media.

What Should I Do During an Outage?

  • Turn off all lights and unplug equipment and computers. Leave one light on to indicate when power has been restored.
  • Do not use candles for illumination due to fire risk. Use battery-powered flashlights instead.
  • Windowless offices without emergency lights should not be occupied during an outage. Where lighting is adequate, employees should continue working, unless otherwise instructed by a supervisor.
  • Employees who leave their offices during an outage should take their personal items and secure their work spaces.
  • Do not use a gas stove for heating or operate generators indoors (including the garage.) Both could cause carbon monoxide poisoning.
  • Do not open refrigerators, freezers, or other environmentally controlled rooms, during the outage. An unopened refrigerator can keep foods cold enough for a couple of hours. A half full freezer will stay cold for up to 24 hours and a full freezer for 48 hours. If you must eat food that was refrigerated or frozen, check it carefully for signs of spoilage.
  • If a traffic signal is not working, treat it as a stop sign.
  • If you are stuck in an elevator, push the alarm or help button and wait for someone to respond.

If you have questions or concerns during an outage, please contact Facilities Management at (949) 824-5444.

How Do I Report Damage Incurred During a Power Outage?

If there is damage to University facilities or equipment, please email the details to riskmgt@uci.edu


Scheduled Power Outages

 Are you prepared for scheduled power outages?

Emergency outlets lose power every month for about 10 seconds. Rigorous monthly emergency power system testing and maintenance is designed to model a real power outage, as close as possible. Testing and maintenance uncovers and eliminates flaws which might prevent emergency systems from performing 100% when needed for an extended real outage. Robust testing includes a full load test of the system, as required by law. Ten seconds are needed for the system to determine if emergency power is needed to start up the generator and to drop the electrical load on to the generator, modeling what will happen if power is lost during an unplanned outage.

The test schedule by building is available online at: Generator/ATS Test Schedule

How to prepare for planned power interruption

Common Misconceptions:

  • Emergency outlets are uninterruptible power
  • Insurance will cover losses
  • If an outlet is open, the circuit must be available

What can you do to be prepared for the monthly test of the emergency power?

  • Inform your staff of the test schedule.
  • Avoid experiments which could be affected by a 10 second power outage that day.
  • After the test, check all equipment to make sure everything restarted properly.
  • Notify your Building Manager or Facilities Management of any equipment which does not turn back on - a circuit breaker may need to be reset. Then, spread the power load to more circuits.

Power Failure Safeguards - Computers

UPS - Uninterruptible Power Supply

  • A short duration UPS is recommended for computers to allow time to shut down the system appropriately if power is lost.
  • During the switchover from regular to emergency power, a short power outage (a few seconds) will normally occur. A UPS system can bridge the power changes and provide uninterrupted power.
  • A sudden power outage to a computer disk drive can cause permanent damage to the disk and to the data on it.
  • UPS systems lasting longer than 1 hour are not recommended. Computers operating on emergency power for long periods suffer from rises in temperature that can lead to permanent damage.
  • If a UPS system is not used - a high quality surge protector is recommended to minimize power fluctuations should a power outage occur.
  • For more information on selecting a UPS see: Selecting a UPS

Power Failure FAQs for Scientific Refrigeration

Information Provided by: Scientific Refrigeration (SR) Medical / Industrial / Laboratory - Refrigeration Service

"Campus Facilities, in compliance with a new state law, will be testing the emergency generators and transfer switches for each building once a month. What this means is that all the emergency outlets in the buidling will experience a 10 second outage while normal utility power is cut and the switch transfers power from the generator to the outlets. When the test is completed the same 10 second outage will occur while the process is reversed. Most of our labs have their -80 freezers and other refrigerated units plugged into emergency power."

UCI Questions and Answers:

  1. If a motor on a refrigerated unit is not active at the time of the test would there be any impact to the equipment?

    There should be no impact to the equipment if the compressor is not running at the time of power interruption. However, a problem could possibly occur if the compressor is in operation. However; most units will withstand this type of test.

  2. What does a 10 second power outage/fluctuation have on the electronics of the freezer?

    There should be no effects on the electronics unless a power shortage or surge occurs. There is likelihood that this can happen if all units start up again at once. Details provided below.

  3. I've attached a copy of the PM recommended by SR and I'm curious, would adhering to this PM on a regular basis be beneficial in helping -80's survive the rigors of this testing?

    Yes. A regular PM would be helpful to insure the proper operation. A dirty air cooled condenser or loose wire will cause a malfunction during a power interruption as well as normal operation.

  4. How often is this pm recommended?

    Every 6 months. This is recommended by SR and by the manufacturer.

  5. Are there issues we haven't even considered that SR would like to make us aware of?

    No matter what precautions are enacted, power interruptions are not desirable for the proper operations of any electrical equipment. You should be aware that a marginally operating freezer will have a greater chance of malfunctioning during this test. Back up plans are suggested – such as having a spare unit. A ready source of dry ice and CO2 or LN2 back-ups on critical contents should be considered. A remote alarm system (Sensaphone or equivalent) is highly suggested so that the owners of the contents can be made aware of failures when not on location and respond ASAP by removing contents and/or calling service into our office or having our answering service contact the 24 hour On-Call technician for emergency services.

  6. What does a 10 second power outage/fluctuation have on the operation of the freezer?

    The main problem with any power outage - occurs upon the restoration of power. When this happens all machinery is trying to start at the same time causing a drop in voltage which in turn causes an increase in amperage or current draw.

    This situation can be improved by the installation of time delays which will enable the various pieces of equipment to start up in a staged manner. While this is not a guaranteed cure-all, it should alleviate most of the problems associated with this power outage test.

    The costs from SR for “time delay” installation:


    • 1 hour on-site labor per unit. (Note: More units being done during same service visit may be less time per unit). Plus travel time (½ hr each way) @ $125 per hour+ $55 service fee
    • Electrical fittings = $5.00
    • Time Delay = $75.00

    If you have multiple units that you would like a quote to install delay timers on, please have a list of your equipment typed up or ready when you call or e-mail us and we can provide a custom quote for your lab.


    Office Contacts: Office Manager: Martha Robinson (Martha@scifrig.com)

    Service Dispatch/Office: Melissa Robbins (Melissar@scifrig.com)

    Parts Manager: Kimberly Robinson (Kimberlyr@scifrig.com)

    Accounting/Office: Desiree Bryan (desireeb@scifrig.com)

Information provided by: Therno Fisher Scientific Research & Design Group

     7. How will the monthly generator and ATS tests impact the -80 ultra-low temperature (ULT) freezers?

All freezers are designed to operate for brief periods of time without power, and operating the generator testing below on a monthly basis should not adversely affect the life of the units appreciably. This is basically the equivalent of just unplugging the units and plugging them back in a couple of extra times per month. All currently produced units with a charged battery installed will run the controls during this period, and they will alarm to alert of a power loss, and also if the temperature rises above the warm alarm setpoint. That said, everything mechanical does wear out at some rate, and starting and stopping the compressors and activating relays more than normal would in theory increase wear, but doing this once per month wouldn’t make much of a difference.

So, I cannot provide a formal letter to state there is absolutely no effect on the life of the freezer, but it should not be significant enough to even be measurable. I can tell you that we have units installed worldwide in facilities (some of which are over 20 years old) with similar generator arrangements and testing regimen, and have no reason to believe it is shortening their life to any measurable level.

Preventive Maintenance Procedures for Scientific Refrigeration

Information Provided by:

Scientific Refrigeration
16511 Burke Lane
Huntington Beach, Ca 92647

Preventative Maintenance Procedures


  1. Check temperature calibration with NIST standards
  2. Check line cord
  3. Check door gaskets and latches
  4. Inspect and clean condenser and compressor area
  5. Check alarm operation and backup battery condition of alarm system and chart recorder (if equipped)
  6. Check recorder operation and calibration
  7. Check wiring for loose connections and burnt wires.
  8. Check all fan motors (condenser & evaporator) for proper operation and condition
  9. Check & Clean Filters

The manufacturers of these types of equipment require that the condensers be cleaned every 3 to 6 months. This is usually noted on the equipment as well as in the operation manual.

The frequency of cleaning the condenser should be determined by the area the unit is located in/near. Laboratories prone to dust and units near high-traffic areas should consider more frequent condenser cleanings. The air filters (if equipped) should be cleaned every 2 to 3 months by end users especially between maintenance schedules.

End users should check gaskets and carefully clean them periodically to report any frost patterns, punctures, or tears. Report any failure symptoms noticed as soon as possible. Corrective actions can be taken in advance of costly disruptive repairs if caught early.

Preventative Maintenance is especially important because it increases the life expectancy of the equipment, allows performance with greater efficiency, and early detection of deteriorating performance can be evaluated and help prevent disastrous failures.

Emergency Outlets and Automatic Transfer Switches (ATS)

An emergency electrical outlet is typically colored red or may have a label identifying the outlet as being supplied by an “emergency source” of power. Beginning July 1, 2010 the red or emergency outlets will have their emergency power sources tested to verify that emergency power is available in the event that the campus experiences an unplanned power outage.

A false belief held by many people is that the “red” outlets will always have power. However, emergency outlets lose power every time the breaker supplying power to them “trips”, or turns off automatically. Unfortunately there have been cases where overloads have caused the breaker to trip off and the emergency outlets have lost power. The loss of power could go unnoticed for days. The breaker must then be manually reset to restore power.

The emergency outlets also lose power every time an electrical outage occurs. The outlets will remain without power until the local emergency generator starts and they will only become energized again once the power is transferred from the emergency generator through the automatic transfer switch and then to the breaker of the emergency outlet. If any of these components fail, the emergency outlets will remain without power until the problem is called into Facilities Management. By the time an Electrician arrives on site and restores power, it is often too late for the critical experiment or research project to continue successfully.

Beginning in July 2010, Facilities Management will begin a new testing program to make certain campus emergency power sources remain functional. During the procedure, power will be transferred from the “Normal” power source to the “Emergency” power source, simulating a power outage. The initial outage is required to take no longer than 10 seconds as the red or emergency outlets are switched from their normal utility power source to their emergency generator power source. Approximately 30 minutes later a power outage of less than 1 second will occur at the red or emergency outlets as the power supplying them is switched back from emergency to normal power.

This test will occur monthly in some buildings and weekly in others as each emergency generator and automatic transfer switch (ATS) is operated. For a schedule of ATS testing see: Generator/ATS Testing Schedule

Special Note: Typical “Ultralow Freezer” (minus 40 to minus 80 deg. C.) response to power interruption

In the event of a power interruption, which includes the ATS testing, the cooling equipment shuts down and the cooling process is stopped. Once power is restored, the controls sequence of operation is initiated. Depending on the age and manufacture, the next step may vary from unit to unit. A local audible alarm sounds and a time delay usually ranging from 1.5 – 15 minutes is started. After the time delay has been satisfied the controls will restart the cooling process and return the unit to normal operation. The audible alarm will continue until someone resets it on the local panel. The time delay is there to protect the cooling equipment and controls from any power spikes when power returns. Some older freezers do not have internal time delays for protection but can be fitted with external protection. There is always the chance that the freezer will not restart on its own. Facilities Management recommends that every freezer with critical contents be fitted with an automatic phone dialer that notifies lab personnel in the event of a failure. Facilities Management will assist you in identifying the correct alarm equipment for your freezers.

Emergency Generator Testing Q&A and Concerns

  1. Why and why now?

    Office of the President General Council directed all campuses to fully comply with state fire codes. This includes Title 19 which covers Emergency Power Supply Systems. CCR Title 19 is a state code that applies to all state buildings, including all UC buildings. Title 19 requires buildings to comply with the California Electrical Codes (CEC). CEC states that emergency generators must be tested monthly, including testing the transfer switch.

  2. Why at 6-8 am?

    The schedule was developed to create the least impact on the Campus educational and research mission. We are willing to work with the research community to adjust the schedule as needed.

  3. Why testing every month?

    Title 19 and NFPA 110 states in section 8.4.2 generator sets in service shall be exercised and tested at least once monthly, for a minimum of 30 minutes.

    See attachment of an emergency electrical diagram.

  4. What is at risk?

    Equipment failure - by running the test in a timed and controlled environment this helps reduce the risk of failures or negative impacts that would occur in the event of a power failure.

  5. What about Closed Transition Automatic Transfer Switches?

    Closed transition automatic transfer switches are a solution to preventing monthly testing outages however they do not represent a “real world outage” which the equipment would experience if the utility power had an actual outage. UPS systems are highly recommended for any equipment that you do not want an outage to occur on. For more information on selecting a UPS see: Selecting a UPS

  6. After each testing, who will be going into labs to check that alarms on equipment are not going off?

    This is a team effort. Facilities Management personnel, the Building Facility Managers, and Laboratory personnel should be on site to assist.

  7. Where do we report problems?

    There will be adequate coverage on site during the test and will be able to respond immediately without delay.

  8. Can you refer us to a website for frequently asked questions on this?

    If you have additional questions after reviewing the information included here, please contact one of the staff mentioned at the end of this section, or your building facility manager.

  9. What can labs do to prepare for the monthly testing?

    An awareness of the testing schedule. Again, this is a team effort and all members of the team should be on site during the test.

  10. Are all the emergency outlets “red”?

    No. Facilities Management can be requested to do an audit and label all receptacles that are on emergency circuits.

  11. Would plugging lab equipment (i.e. -80 freezers) into regular outlets prior to the emergency generator/AST testing, and then switch back to the emergency outlets once testing is complete be a solution or would the turning off and on the freezer to do this cause the same problem as a short power outage that will occur during the test?

    A combination of preventative maintenance and a properly sized UPS system is the best way to insure that the minus 80 freezers will not fail in any type of power interruption.

  12. Will the monthly testing take more than an hour to achieve?


  13. Who is in charge of this project?

    Jerry Nearhoof, Assistant Director of Central Plant gnearhoo@uci.edu, extension 4-2781

Title 19 Adoption on Campus

This document is to help define State Legislation and the code adoption process at the University.

UCOP (University of California, Office of the President)

UCOP defines the policies, procedures, and guidelines for all its facilities. Within these policies, the Regents’ have adopted the California Code of Regulations, Title 19, State Fire Marshal Public Safety.

California Code of Regulations, Title 19, Public Safety

  • Article 3.01 Basic Electrical Regulations
    • Buildings regulated by these code shall conform to provisions of Part 3, Title 24, California Administration Code (California Electrical Code)

CEC (California Electrical Code)

    • CEC adopts the National Fire Protection Agency 110 Standard which regulates inspection, testing, and maintenance of Emergency Power Systems (Emergency Generators)

NFPA 110, Standard for Emergency and Power Supply Systems (Emer. Generators)

  • This standard requires the following:
    • Emergency generators shall be ran for 30 minutes monthly
      • There is no interruption to power during this process; engine running only
    • ATS (Automatic Transfer Switch) to be exercised monthly
      • The ATS transfers power from normal power supply to the emergency power from the generator
      • This test has a maximum transfer time of 10 seconds. This is the time when the power loss occurs to the emergency circuits, including red outlets
      • ATS Testing Methods
        • Exercising ATS by manually switching the “Test” switch
        • Shutting off power at the main breaker
          • Not required

Risk Management Claims


Each claim must be evaluated on its own merits and should be reported to Risk Management. Ultimately, Office of the President and our Third Party Claims Administrator will determine applicable coverage.

As a general guide the following information may be helpful.

  1. Animals are generally excluded from coverage.

  2. In order for coverage to apply to a freezer’s contents, there generally must be some damage to the freezer or associated electrical circuits which in turn causes the failure of the freezer. Tripped circuit breakers and blown fuses do not constitute damage. Thus if a breaker trips and a freezer thaws there will not be coverage for the freezer contents. If however, the freezer motor burns up and is destroyed as a result of power failure restart, you should have coverage for the freezer repair and replaceable contents.

  3. Insurance generally will not cover costs to redo research or re-create lost research. It is designed to cover off the shelf materials. Thus, you would be able to replace commercially available reagents and other commercially available materials, but you would not be able to re-create a multi-generational tissue sample.

  4. Claim payments only come after complete investigation and documentation is supplied to OP and the claim is authorized. Claim payment journals are prepared by OP and sent to Campus Accounting. This process often takes 3-4 months after submission. Campuses are expected to provide necessary funding to keep operations moving and should not put research on hold pending claim payments. In certain instances (usually large claims) Risk Management can obtain funding or partial funding up front, but the process is not immediate.

For a copy of a claim form from Risk Management see: Risk Management Claim Form

Selecting a UPS

Why use an Uninterruptible Power Supply (UPS)?

In general, a UPS system protects electrical loads and equipment from certain problems of the electrical power supply, performing the following three basic functions:

  1. Preventing hardware damage that may be caused by electrical noise (e.g., harmonics, surges, spikes). Many UPS models continually condition incoming power to remove noise.
  2. Preventing data loss and corruption that may occur due to temporary (short duration) loss of power. Without a UPS, devices that are subjected to a hard system shutdown can lose data completely or have it corrupted even during momentary (e.g., 1 second) loss of power. In conjunction with power management software, a UPS system can ride through momentary power loss and/or facilitate a graceful system shutdown.
  3. Providing availability (preventing downtime) for electrical loads and equipment. In some cases, a UPS system can provide enough battery runtime to power equipment through significant (longer duration) power outages. UPS systems are often paired with generators to provide enough time for the generator to power up for longer duration power outages.

UPS design considerations:

Characterization of the Load:

The volt-amp (VA) or watt (W) power rating of the electrical loads one wants to protect is one of the most important factors in identifying the correct UPS for the application. In addition, one must identify the voltage (e.g., 120 volts), frequency (e.g., direct current (0 Hz), alternating current (60 Hz)), and power environment (e.g., single-phase or three-phase) to determine the size and characteristics of the UPS system required.

Picking Your UPS:

The true runtime requirement for the equipment one wants to protect must be determined. Each application will be different based on your equipment load, desired runtime and the manufacturer of the UPS you select. You can get a rough estimate of your UPS runtime by using the online estimators provided by each manufacturer. Here are links to several of them:

Runtime Chart for Smart-UPS - APC

UPS Systems & Battery Packs / Tripp Lite

Scheduled and unscheduled temporary power outages are communicated via campus email. You can be added to the Facilities Management Utility Outage listserv by subscribing via the ZotMail website at:

My ZotMail

UPS Topologies:

There are several different UPS topologies that provide varying degrees of protection. Selecting the best fit for your equipment depends upon several factors, including the level of reliability and availability desired, the type of equipment being protected and the application/environment. While all three of the most common UPS topolgies outlined below meet the input voltage requirements for IT equipment, there are key differences in how the result is achieved, as well as the frequency and duration of demands on the battery.

Standby UPS systems allow equipment to run off utility power until the UPS detects a problem, at which point it switches to battery power to provide power during an outage. Voltage and frequency of the power are usually perturbed and may be temporarily lost during the transition, which may or may not be a challenge for your particular equipment. This topology is best suited for applications requiring simple backup such as a small office/home office and/or point-of-sale equipment that must remain available during temporary outages.  

Line-interactive UPS systems actively regulate voltage either by supplying power to the battery or receiving power from the battery as necessary to precisely regulate voltage before allowing it to pass to the protected equipment. Line-interactive models are ideal for applications where protection from power anomalies (e.g., voltage surge or sag) is required, but the utility power is relatively clean. MDF (Main Distribution Frame) and IDF (Intermediate Distribution Frame) communication closets, non-centralized server and network rooms, and general IT enclosures are well-suited for this topology.

Online UPS systems provide the highest level of protection by isolating equipment from utility power - converting all of the power from AC to DC and back to AC. Unlike other topologies, double conversion provides zero transfer time to the battery with seamless transition from utility power to battery power and vice versa that may be required for sensitive equipment. This topology is best applied to mission-critical equipment that cannot withstand even momentary power loss.

UPS Battery Overview:

It is well known that the battery is the most vulnerable part of a UPS system. In fact, battery failure is a leading cause of load loss during UPS operation. Understanding how to properly maintain and manage UPS batteries can extend their service life and help prevent costly downtime.

Valve-regulated lead acid (VRLA) batteries, also known as sealed or maintenance free lead acid batteries, are most commonly used in UPS systems. VRLA batteries are sealed, usually within polypropylene plastic, which offers the advantage of not containing any sloshing liquid that might leak or drip. Because water can't be added to VRLA batteries, recombination of water is critical to their life and health, and any factor that increases the rate of evaporation or water loss, such as temperature or heat from the charging current, reduces battery life.

Smaller UPS systems are beginning to become available using rechargeable lithium-ion or nickel-cadmium (Ni-Cad) batteries.

Frequently asked questions: Batteries:

1. What is the "end of useful life"?

The IEEE defines "end of useful life" for a UPS battery as the point when it can no longer supply 80 percent of its rated capacity, in ampere-hours. When your battery reaches 80 percent of its rated capacity the aging process accelerates and the battery should be replaced.

2. What is the difference between hot-swappable and user-replaceable batteries?

Hot-swappable batteries can be changed out while the UPS is running. User-replaceable batteries are usually found in smaller UPS systems and require no special tools or training to replace. Batteries can be both hot-swappable and user-replaceable.

3. How is battery runtime affected if I reduce the load on the UPS?

The battery runtime will increase if the load is reduced. As a general rule, if you reduce the load by half, you triple the runtime.

4. If I add more batteries to a UPS, can I add more load?

Adding more batteries to a UPS can increase the battery runtime to support the load. However, adding more batteries to the UPS doesn't increase the UPS capacity. Be sure your UPS is adequately sized for your load and then add batteries to fit your runtime needs.

5. What is the average lifespan of UPS batteries?

The standard lifespan for VRLA batteries is three to five years. However, expected life can vary greatly due to environmental conditions, number of discharge cycles, and adequate maintenance. Have a regular schedule of battery maintenance and monitoring to ensure you know when your batteries are reaching their end-of-life.

6. How can you be sure UPS batteries are in good condition and ensure they have maximum holdover in the event of a power failure? What preventive maintenance procedures should be done and how often?

The batteries used in the UPS and associated battery modules and cabinets are sealed, lead-acid batteries often referred to as maintenance-free. While these types of batteries are sealed and you don't need to check their fluid level, they do require some attention to assure proper operation. You should inspect the UPS a minimum of once per year by initiating a self-test.

7. How long does it take for the UPS batteries to recharge?

On average, it takes 10 times the discharge time for the UPS batteries to recover. (A 30-minute battery discharge requires about 300 minutes to recharge.) After each power outage, the recharge process begins immediately. It's important to note that the load is fully protected while the batteries are recharging, but if the batteries are needed during that time, the holdover time available will be less than it would have been if the batteries were fully charged.

8. What are the risks associated with a lack of battery maintenance?

 The primary risks of improperly maintained batteries are load loss, fire, property damage and personal injury.

9. What is thermal runaway?

Thermal runaway occurs when the heat generated in a lead-acid cell exceeds its ability to dissipate it, which can lead to an explosion, especially in sealed cells. The heat generated in the cell may occur without any warning signs and may be caused by overcharging, excessive charging, internal physical damage, internal short circuit or a hot environment.

10. Why do batteries fail?

Batteries can fail for a multitude of reasons, but common reasons are:

  • High or uneven temperatures
  • Inaccurate float charge voltage
  • Loose inter-cell links or connections
  • Loss of electrolyte due to drying out or damaged case
  • Lack of maintenance
  • Aging

11. How is battery performance generally measured?

Batteries are generally rated for 100+ discharges and recharges, but many show a marked decline in charging capacity after as few as 10 discharges. The lower the charge the battery can accept, the less runtime it can deliver. Look for batteries with a high-rate design that sustains stable performance for a long service term.

Factors affecting battery life:

All UPS batteries have a limited service life, regardless of how or where the UPS is deployed. While determining battery life can be tricky, there are four primary factors that contribute to a battery's overall lifespan.

1. Ambient Temperature

Because the rated capacity of a battery is based on an ambient temperature of 25oC (77oF), any variation from this can affect performance and reduce battery life. For every 8.3oC (15oF) average annual temperature above 25oC (77oF), the life of the battery is reduced by 50 percent.

2. Battery Chemistry

UPS batteries are electro-chemical devices whose ability to store and deliver power slowly decreases over time. Even if all guidelines for storage, maintenance and usage are followed, batteries will still require replacement after a certain period of time.

3. Cycling

After a UPS operates on battery power during a power failure, which is called the discharge cycle, the battery is recharged for future use. At installation, the battery is at 100 percent of its rated capacity, but each discharge and subsequent recharge slightly reduces its relative capacity. Once the chemistry is depleted, the cells fail and the battery must be replaced.

4. Maintenance

For larger UPS models, service and maintenance of batteries are critical to its reliability. Periodic preventive maintenance not only extends battery string life by preventing loose connections and removing corrosion, but can help identify ailing batteries before they fail. Even though sealed batteries are sometimes referred to as maintenance free, they still require scheduled service, as "maintenance free" refers only to the fact that they don't require replacement fluid.

Frequency Asked Questions:

1. What's the difference between a surge protector and a UPS?

A surge protector provides just that - surge protection. In addition to surge protection, a UPS continually regulates incoming voltage and provides battery backup in the event of a power failure. You'll often see surge protectors plugged into a UPS for added surge protection and additional output receptacles.

2. How is battery runtime impacted if I reduce the load on the UPS?

There can be a significant increase in runtime. Generally speaking, a UPS that provides five minutes at full load will provide 15 minutes at half load.

3. My research is too small for protective measures. Do I really need a UPS?

Power problems are equal-opportunity threats. Your PCs, servers and network are just as critical to your research as a data center is to a large enterprise. Downtime is costly in terms of hardware and potential loss of goodwill, reputation and sales. Also add in delays that inevitably occur when rebooting locked-up equipment, restoring damaged files and re-running processes that were interrupted. A sound power protection strategy is cost-effective insurance.

4. Why is power quality such a problem today?

Today's high-tech IT equipment and control units are much more sensitive to electrical disturbances and are more important to the critical functions of many businesses than in the past. As a result, power quality problems today are more frequent and more costly than ever.

5. Are power quality problems always noticeable?

No. In many cases, disturbances can cause imperceptible damage to circuits and other components, a major cause of premature equipment failure and problems like computer lockups. Many power quality problems go unresolved, resulting in lost revenue and data.

6. We have a generator. Do I still need a UPS?

Many customers don't realize that a generator will NOT protect their equipment against power problems. You need a UPS to guarantee that the equipment stays up until the generator kicks on and stabilizes - which often requires several minutes.

7. How much UPS capacity do I need?

Determine the total load (in watts) of the equipment you want to protect.