uninterruptible power supply | APC UPS Blog

What to do when the “replace the battery” light comes on?

An uninterruptible power supply (UPS) is very useful in ensuring continuous power supply to electronic devices when the main power source goes out. A UPS features a battery where power, used to protect against power failures, is stored. While there are several factors affecting battery life, the lifespan of most UPS batteries ranges from three to five years. When it becomes necessary to replace the battery, the “replace the battery” light normally comes on.

But, there are instances when the light would come on unexpectedly even though the battery has not yet reached the end of its lifespan. These situations normally happen when the self-test fails. A self-test checks the attached load of a UPS by switching its power source to the battery.

To check whether the battery is still good or not, the UPS should be unplugged from the external power source and the UPS is allowed to run on the battery. If the voltage of the battery goes down drastically, the battery will have to be replaced.

But, if the voltage remains constant, the UPS should be turned off completely. This can be done by removing the attached load, unplugging the UPS and disconnecting the battery. Then the “on” button of the UPS is held down for five seconds before the battery is reconnected. The UPS is then plugged into an external power source. After this, the UPS can be switched on.

There are also instances when the light turns on after the battery of the UPS is replaced. To clear this status, it is necessary to ensure the battery is fully-charged before running a valid self-test.

To make sure the battery of a UPS reaches its optimum life span, the UPS should be positioned in a cool and dry location. It is also important to keep the load on the UPS under 80 percent of the rated capacity of the battery to increase its lifespan.

References:

http://forums.apc.com/spaces/4/back-ups-surge-protectors/forums/general/12481/ups-asking-for-me-to-replace-the-battery-but-the-battery-seems-fine

http://arstechnica.com/civis/viewtopic.php?t=127536

http://serverfault.com/questions/193503/how-to-clear-the-replacebatt-state-from-apc-ups-after-hot-swapping-the-battery

http://apcpartnercentral.com/edge-applications/how-do-i-know-when-my-ups-needs-a-battery-replacement-intelligent-battery-management-and-the-new-smart-ups-on-line.html

http://www.apc.com/us/en/faqs/FA158934/

What are Frequency Variations?

Frequency is a change in the way alternating current (AC) flows. Frequency is closely connected to the speed of the rotation of the motor of a generator. The frequency of power generators in the United States and other countries is 60 Hz and the motors of these generators rotate at 3600 rpm. Variations in frequency can cause the rotation in the motor to change. When this happens, there will be changes in the efficiency of the motors.

Areas connected to a stable power grid do not typically experience frequency variations. Frequency variations normally affect areas using a dedicated power generator. High demand for power worsens the situation. While this common power problem does not affect computer systems, it does have a negative effect on the efficiency of devices dependent on a stable frequency. Similar to voltage fluctuations, frequency variations can also cause lights to flicker.

These frequency variations may make the rotation of the motors faster or slower since they will have to match the frequency of the power input. This will cause the motors to become inefficient. It may also cause the motors to heat up over time and result in the gradual breakdown of the motor. There may be some rare instances when power failure will happen due to frequency variations.

To deal with frequency variations, it is necessary to check all sources of power. After assessing the power sources, it is important to make the necessary repairs or corrections, and, if needed, replace them. It may also be necessary to move sensitive loads to manage this common power problem. The use of an uninterruptible power supply (UPS) system and a power conditioner can reduce the effects of frequency variations.

What are Voltage Fluctuations?

A voltage fluctuation is a regular change in voltage that happen when devices or equipment requiring a higher load are used. The effects of a voltage fluctuation are similar to the effects of an undervoltage. It causes lights to flicker or glow brighter. Display screen may flicker as well. There are also some instances when electronic equipment, such as a computer, will fail to start up. In addition, voltage fluctuations can cause computer systems to lose data, while televisions or radios may experience interference. This power problem can have a significant effect on the lifespan of incandescent bulbs, since they are designed for a specific voltage.

Rural areas may experience dramatic voltage fluctuations due to the long power lines. These power lines can cause voltage to go down when power usage in the area is high. When arc furnaces, arc welding equipment or even elevators are used, they normally cause the voltage of a power distribution system to fluctuate. This situation is similar to using a shower in the second floor bathroom of a house. When someone turns on the faucet in the laundry room on the first floor, the second floor shower may run out of water.

Voltage fluctuations can be managed through the use of a voltage regulator. An uninterruptible power supply (UPS) system or power line conditioning devices can also be used in reducing the effects of this common power problem. Another way to deal with voltage fluctuations is by simply removing equipment or devices causing it from the power supply system.

References:

http://northpower.com/network/services/voltage-fluctuations

http://www.apcmedia.com/salestools/VAVR-5WKLPK/VAVR-5WKLPK_R1_EN.pdf?sdirect=true

http://www.on365.co.uk/Power__and__Cooling/Most_Common_Power_Problems.aspx

https://www.linkedin.com/pulse/6-common-power-problems-ted-ochieng-otieno-cem-?forceNoSplash=true

http://electrical-engineering-portal.com/9-most-common-power-quality-problems

http://blog.schneider-electric.com/datacenter/power-and-cooling/2013/05/28/six-types-of-power-disturbances-that-can-trip-up-your-it-systems/

What are waveform distortions?

Waveform distortions are common power problems that cause equipment to malfunction and sources of power to overload. It is an unexpected change in the waveforms of current and voltage as they pass through a device. There are five main types of waveform distortions: DC offset, harmonics, interharmonics, notching and noise.

DC offsets are instances where direct current (DC) overlaps an alternating current (AC) distribution system. This overlapping of two different types of current can cause overheating in the equipment.

Harmonics occur when some loads affect the main waveform of voltage. In this situation, the new loads prevent the waveform from reaching its highest and lowest levels. Harmonics can cause circuit breakers to trip and transformers to overheat.

Interharmonics is a condition where a signal affects the main voltage waveform. It can cause display monitors to flicker and equipment to overheat. Interharmonics can also cause communication issues.

Notching is an intermittent disturbance that can affect voltage. It normally happens when light dimmers or arc welders are being used. It results in data loss and issues with the transmission of data.

Noise is any unnecessary current or voltage affecting the waveform of the main power supply. This waveform distortion can cause data issues and equipment to malfunction.

The effects of waveform distortion can be reduced through the use of an uninterruptible power supply (UPS) and filter equipment. Line conditioners can also be used to minimize the effect of this power problem. Reducing the load used on a transformer can also help reduce waveform distortion. Relocating equipment causing this common power problem can also help prevent it from happening.

References:

http://ecmweb.com/content/voltage-waveform-distortion-causes-effects-cures

http://www.dictionaryofengineering.com/definition/waveform-distortion.html

http://www.apcmedia.com/salestools/VAVR-5WKLPK/VAVR-5WKLPK_R1_EN.pdf?sdirect=true

https://www.tripplite.com/shared/literature/White-Paper/Common-Power-Problems-and-Power-Protection-Solutions-White-Paper-EN.pdf

https://www.linkedin.com/pulse/6-common-power-problems-ted-ochieng-otieno-cem-?forceNoSplash=truehttps://www.captech.com.au/2016/05/06/common-issues-with-power-supply/

What are Swells and Overvoltages?

Swells and overvoltages are basically the opposite of sags and undervoltages. A swell is an increase in voltage lasting up to one minute, and an overvoltage is the long-term effect of a swell. These situations happen when available voltage is higher than the demand. It normally starts when there is a huge demand for power. Due to this, utility companies normally increase voltage to meet the demand. When the demand goes down rapidly, there is the possibility that the voltage will remain high causing the swell or overvoltage.

These power problems normally affect rural areas since utility companies usually leave voltage at a high level over the weekend even after the demand has gone down. These situations also happen when the system voltage regulator is inefficient, or when the transformer settings are not set properly by the power company.

Even when overvoltages are brief, they can be damaging to equipment. These power problems can cause equipment to overheat and damage them. They may also cause lights and monitors to flicker. Data centers are susceptible to these situations since they may cause data errors in computer systems. Semiconductors may also be damaged by overvoltages and swells.

To prevent swells and overvoltages from affecting sensitive equipment, it is necessary to use an uninterruptible power supply or UPS system. While the most basic protection against this power problem is a standby UPS system, the best way to protect equipment from a swell or overvoltage is by using an online UPS. These devices protect equipment from sudden increases in voltage. They automatically adjust voltage in case these power problems occur to ensure electricity-powered equipment are protected.

Sources:

http://www.on365.co.uk/Power__and__Cooling/Most_Common_Power_Problems.aspx

http://www.apcmedia.com/salestools/VAVR-5WKLPK/VAVR-5WKLPK_R1_EN.pdf?sdirect=true

https://www.linkedin.com/pulse/6-common-power-problems-ted-ochieng-otieno-cem-?forceNoSplash=true

https://www.tripplite.com/support/articles/articleid/common-power-problems

http://www.acousticfrontiers.com/201348what-are-swells-and-overvoltages/

http://electricity2all.blogspot.com/2013/05/over-voltage-and-voltage-swell.html

What is a Sag or Undervoltage?

A sag or an undervoltage is a temporary decrease in power lasting up to over a minute. A sag or an undervoltage typically happens whenever heavy machinery is turned on. A great amount of power is used by the heavy machinery during startup, leaving a small amount or power available for other equipment to use.

Voltage sags also happen when the main source of power is affected by natural events like lightning strikes, strong winds and power lines getting hit by falling tree branches. A sag or an undervoltage may affect equipment within 100 miles of the main power grid of a utility company.

Due to this, overheating can occur for some equipment while others may malfunction. Lights may also dim, and batteries may not be charged properly due to an undervoltage situation. An undervoltage or sag may cause a computer to lose data and systems to lock up.

In the past, the term brownout was used to describe this situation. However, its use has been discouraged by an international standards organization, the Institute of Electrical and Electronics Engineers. The term brownout is typically used for situations where the lack of power lasts for a couple of hours.

To handle undervoltages and voltage sags, you can provide heavy machinery their own circuit and avoid connecting them to the circuits used by other equipment. Automatic voltage regulators can also reduce the effects of undervoltage and voltage sags. These devices regulate the level of voltage used by specific equipment and ensure they always receive a suitable amount of power.

An uninterruptible power supply or UPS can also protect equipment from voltage sags. The batteries of these devices provide power for a specific period of time as long as the batteries are not dead. The batteries of a UPS normally last up to around 20 minutes.

References:

http://www.on365.co.uk/Power__and__Cooling/Most_Common_Power_Problems.aspx

https://www.tripplite.com/support/articles/articleid/common-power-problems

http://www.controleng.com/single-article/voltage-sags-and-what-to-do-about-them/0499ada0dfbb1d6747ee2bf3adacd2ee.html

http://www.electricalsolutions.net.au/content/electrical-distribution/article/understanding-the-most-common-power-quality-problems-897329076

http://www.powerqualityworld.com/2011/03/power-quality-basics-undervoltage.html

http://www.hersheyenergy.com/voltage_irregularities.html

What is a UPS?

UPS is the acronym for uninterruptible power supply. It is a system that ensures sensitive electronic devices, such as servers and PCs, continue to operate if and when the main power source goes out. A UPS normally provides enough power for a few minutes to allow you to save your work before the computer shuts down.

A UPS system gives instant protection from power failures through the power stored in its batteries. While it may be possible for a standby generator to automatically start up when a power failure occurs, there is a short delay before the generator provides the power needed to keep your PC running. This is where a UPS system comes in since it provides you enough power while your standby generator is starting up.

It is also important to take note that a UPS system should not be considered as a replacement for a standby generator since it only provides enough power for a few minutes. A UPS system is normally used together with a standby generator in data centers since it fills in the gap in between the interruption of the main power supply and the replacement power provided by the standby generator.

Many UPS systems feature a software component facilitating the automatic backup and shut down of your PC whenever the main power source is interrupted. This feature is useful if you are not close to your computer when a power failure occurs.

The most common type of UPS system used in the market is an online UPS system. It is made up of a charger or rectifier, power inverter, and batteries. The power that passes through the charger and inverter is in the form of alternating current (AC) before it is stored in the batteries as direct current (DC). Whenever the main power source is interrupted, the DC power is converted into AC before it is used to power the devices connected to the UPS system.

References:

http://www.webopedia.com/TERM/U/UPS.html

http://www.businessdictionary.com/definition/uninterruptible-power-supply-UPS.html

http://www.amps.org.uk/what-is-ups-

http://www.wikiforu.com/2012/07/classification-types-of-uninterrupted-power-supply-ups.html

Seven Main Types of Power Problems

Issues with power supply often lead to losses amounting to billions of dollars every year. The following are the seven main power problems identified by an international standards organization, the Institute of Electrical and Electronics Engineers.

Transients

Transients are the most damaging types of power problems. These are sudden changes in power and are referred to as power surges or power spikes. In this situation, power goes up beyond its normal range and causes an overload, which in turn causes damage to equipment connected to it.

Interruptions

An interruption is a total loss of power resulting from damage to the power supply grid. The damage may be caused by equipment failure or lightning strikes, among others. These interruptions may last from a few seconds to a couple of hours.

Sag or Undervoltage

A sag or undervoltage is basically a temporary drop in the power whenever heavy machinery is used. Power supply drops since these machines require a huge amount of power. The situation was once called a brownout before the term undervoltage was used.

Swell/Overvoltage

A swell or overvoltage is the opposite of a sag or undervoltage. It is a situation when the power supply is higher than the demand for it. Swells or overvoltages can cause equipment to overheat and lights to flicker.

Waveform distortion

Waveform distortions are changes in the frequency leading to data loss and equipment failure. The five main types of wave distortion problems are DC Offset, Notching, Noise, Harmonics, and Interharmonics.

Voltage Fluctuations

Voltage fluctuations are situations when voltage rises and falls erratically. Whenever machinery with high power needs is turned on, voltage fluctuations normally occur.

Frequency variations

Frequency variations normally happen in areas powered by a standby generator or areas with an unstable power supply. Equipment connected to these power sources will operate inefficiently.

These power problems can be remedied through the use of appropriate UPS systems available in the market today.

References:

http://www.on365.co.uk/Power__and__Cooling/Most_Common_Power_Problems.aspx

http://www.apcmedia.com/salestools/VAVR-5WKLPK/VAVR-5WKLPK_R1_EN.pdf?sdirect=true

https://www.linkedin.com/pulse/6-common-power-problems-ted-ochieng-otieno-cem-?forceNoSplash=true

What is an Uninterruptible Power Supply?

Join us as we discuss the basics of power back ups over the next few posts. We’re going to keep these posts short and simple. Please leave questions in the comments.

What is an Uninterruptible Power Supply?

An uninterruptible power supply, also known as a UPS, battery backup or power back up is a device that provides power to attached equipment when the utility power goes out. The main idea of a UPS is to provide instant power without interruption to the attached devices. That way, the computer or server attached will not lose power but will continue running uninterrupted.

Common Names for Uninterruptible Power Supplies:

– Uninterruptible Power Supply

– Uninterrupted Power Supply

– Battery Backup

– Power Backup

– UPS Backup

– UPS

All of the above terminology basically means the same thing. So if you want be part of the cool club, call it a “UPS”. How do you pronounce that? That’s a great question, it’s pronounced like the shipping company, “UPS”. It’s not pronounced like the “UPS” in the diapers “Pull Ups”.

What are Uninterruptible Power Supplies used for?

– Computers

– Servers

– Data centers

– Telecom equipment (voip, pbx, phone system)

– Medical Equipment

– POS Equipment (cash registers, debit machines)

– ATM, ABM

and every other piece of equipment that can be harmed or cause harm by suddenly losing power. You might not have noticed them before, but they’re pretty much everywhere. Your local bank has them, the grocery store and your internet service provider.

In the next few posts, we are going to discuss:

Different types of UPSs
Main Features
Power Problems

If you have any questions please post them in the comments or post them up on our Q&A Site