Uninterruptible Power Supply Accomplishes Immediate Power Supply Requirements

Nowadays, with the advent of technologies, people dependency upon electricity is increased as most of the modern equipments and appliances require electricity to run efficiently. If you experience frequently power cuts, then you have to search for an alternative as they may cause huge loss especially when you work on important projects on your computer. Keeping in mind various types of requirements of people, Uninterruptible power supply, also known as a battery backup, has been introduced. The equipment provides a source of electrical energy to keep continuity on your appliance during an interruption in mains electricity or until an alternative source of energy, like generator, starts up.

Types of uninterruptible power supply come up

Advantages of UPS

A UPS is a very useful device which plays an important role in preventing unscheduled downtime or data loss due to frequent power cuts. Some of the common features of a modern UPS include the surge suppression built-in device, hot-swap power module and battery module replacements. It also enables people to know the time left for them to save their data before it completely gets shut down.

A UPS comprises of numerous components such as rectifier, inverter, charger, battery, static switch, maintenance bypass, external maintenance bypass and so on. All these parts carry out different functions and accomplish the requirement of power supply to a computer system or other electronic devices which require immediate power supply to run effectively. If you want to buy a UPS, then it is advised to look for online stores as they sell their products at cost effective rates and provide repairing services free of cost for a certain period of time.

Uninterruptible Power Supply – Power Conditioning

Power conditioning is one of the lesser-known but equally important functions of an uninterruptible power supply (UPS). Its primary purpose, of course, is to provide a source of electrical energy to maintain continuity of business throughout an interruption in mains electricity or until an alternative source of energy (such as a generator) starts up.

Why the Need for Power Conditioning?

 There are issues associated with raw mains electricity that can cause problems for electronic equipment. These include, but are not limited to: sags, surges, brownouts, spikes and transients, electrical noise, harmonics, frequency variations and, of course, complete blackouts. At best, power problems can cause equipment (particularly computer and telecommunications equipment) to lock or crash. At worst, they can result in a complete breakdown – thus entailing costly and disruptive repair and/or replacement. In the case of computers, they can also result in data being lost or corrupted, which for many industries that are heavily regulated (such as banking and finance) can be disruptive to business, damaging to reputation and credibility, and in extreme cases, can lead to heavy fines or financial penalties.

Power Conditioning, therefore, by uninterruptible power supplies and associated equipment, is a process by which it monitors incoming mains electricity, cleanses it and significantly reduces the effect of problems such as those highlighted already. Some UPS, fitted with special filters, can reduce the effect of harmonics.  All UPS maintain frequencies to within prescribed limits thus correcting frequency fluctuations. Ultimately, this means protected loads upstream, receive a clean and regulated supply of electrical energy.

Power Conditioners

Power conditioners attenuate spikes, transients and electrical noise voltages to low levels. They can be solid state electronic or transformer-based. Where these types of problems predominate, and sensitive equipment is being protected, that’s where power conditioners will be used, typically in industrial environments. Some power conditioners can also provide voltage stabilization over a wide input voltage window (typically minus 20 to plus 15%) and output voltage regulation (typically plus or minus 5%). Models of this type can be referred to as Constant Voltage Transformers (CVT) or Ferroresonant type design.

This type of transformer is more reliable than a solid-state electronic design and provides galvanic isolation (a means of preventing unwanted electrical currents from traveling between two separate units). It’s history rest in uninterruptible power supply designs from the 1980s (known as Ferro UPS), which paired the CVT with a Line Interactive UPS to achieve a ‘no-break’ output. Though reliable and robust, this type of uninterruptible power supply was only practical for single-phase installations and couldn’t compete on cost, noise, physical size and weight, with transformerless UPS designs that were beginning to emerge.

Automatic Voltage Stabilisers (AVS)

AVS provide protection from sags, brownouts and surges. They can be electro-mechanical or solid-state electronic devices and are often referred to as Automatic Voltage Regulators (AVRs). AVS typically have wide input voltage windows (minus 40 to plus 20%) to enable them to do their job. When presented with a low or high mains power supply voltage, a control circuit selects a transformer tap setting to buck (step down) or boost (step up) the voltage to more acceptable levels. The output voltage tracks the input voltage window as there is, typically, no voltage regulation.

Some Automatic Voltage Stablisers incorporate a filter to provide both the load and AVS with protection from spikes, transients and electrical noise. The primary application of an AVS is in remote areas where sags, surges and brownouts are common to protect equipment such as fridges, freezers and domestic electrical goods.

Filters and Filter Strips

Filters provide protection from spikes, transients and electrical noise. Instead of attenuating problems like power conditioners, filters clamp peak voltages to pre-defined levels and prevent damaging electrical noise from passing through to connected loads.

There are a number of filters available and performance varies considerably across the range. Filter (surge) strips, for example, are commonly used within ICT environments for power distribution. At the higher end, more specialist filters can be acquired for specialist environments, such as scientific laboratories. Filter performance, clamping level and speed of response, is dependent upon their circuit design and the size of the disturbance it is faced with.

Transient Voltage Surge Suppressors (TVSS)

TVSS provide protection from transient voltages and high-energy spikes, particularly those induced into a building’s electrical supply by local lightning strikes. They are rated in terms of the Amps (A) or Joules (J) they dissipate. They usually sit parallel to the load and only react when presented with a transient or high-energy surge.

When installed within a building, a ‘zoned approach’ is recommended, which places high rated devices before distribution boards. A TVSS may be fitted upstream of a UPS or inside a bypass panel, generator AMF panel or distribution boards to provide protection from nearby lightning strikes.

TVSS designs tend to be based around Metal Oxide Varistors (MOVs) rather than Gas Discharge Tubes (GDTs) typically found in surge suppressors. Some manufacturers combine their MOV designs with a Silicon Avalanche Diode (SAD) front-end to speed up their response time.

Uninterruptible Power Supply Symbolizes with Protection of Electronic Appliances

Uninterruptible power supply or UPS devices are the essential requirement of every household and commercial establishments as well as important organisations. They supply continuous power to electronic appliances in the absence of power failure or any other faulty condition. For airports, gas stations, hospitals and research organisations, these devices are vital to keep important works continue. Such types of devices keep the flow of electric power continue for a few minutes to hour in case of any faulty condition, power failure, brownouts, spikes and surges. Without any doubt, uninterruptible power supply devices including UPS systems have changed the definition of power supply in an efficient manner.

Now, in every household, commercial establishments and important organisations, these devices are used widely to keep the flow of power continue. Put simply, such devices have reduced the chances of potential damages due of electronic appliances to a great level. Devices of uninterruptible power supplies are usually divided into different forms named standby online and line interactive UPS systems. No doubt, they are the appropriate solutions for managing power related problems in an efficient manner. When the power fails from the main line, a switch is automatically turned on and the supply of power starts from the battery rather than from the standard line voltage.

It is a fact that these devices keep electronic appliances protected beyond your expectations with the help of their superior power-conditioning capabilities. Put simply, they are the essential tool for mission-critical applications. Interestingly, these devices also come in different strength ratings from 200 VA to 4.8 mVA. Interesting fact about the systems is such types of systems up to 3 kVA are normally Plug & Play as well as user installable. When it comes to installation of UPS systems over the aforesaid capacity, it requires electrical installation by qualified and skilled engineer. It is a fact that people buy them according to load and budget. It is one time investment and long-term benefits.

If count annual basis, then because of these devices you save a good amount of money that is usually spent over the repairing of electronic appliances (sometimes, the electronic appliance are damaged because of unexpected power failure or any other power related problem). Today, marketplaces in all parts of the world is flourished with a variety of uninterruptible power supplies, you can select one according to your requirements and budget. You can also get uninterruptible power supplies online by simply placing your order online by mentioning the details of power load and budget.

Uninterruptible Power Supply Provides Continuous Power Supply during Fluctuation

Unexpected surges or spikes in voltage can damage sophisticated electronic devices such as computers. However, the damage may be swift and sudden; resulting in limited or total memory loss, corrupted data and also resulting in shorter computer life as well as high repair bills. If you want to guard against any kind of loss and also don’t want to pay in repairing, then connect your electronic appliances with uninterruptible power supply units to keep them humming during blackouts, surges, faults and even power cut.

Uninterruptible power supply units reduce the chances of damage in electronic appliances

Today because of sudden power failures, uninterruptible power supply (UPS) units are believed to be backbone of electronic devices. These units not only keep your electronic appliances protected from sudden damages due to power cut, but also keep them running in the event of a blackout from a few minutes to the whole day. A good quality UPS in the event of power cut provides clean and conditioned AC power to computer and other electronic appliances.

Big changeability in voltage can overwhelm the computer

It is absolutely correct that big fluctuations in voltage can crush the computer, even data can be corrupted, files can be lost and delicate circuits can be fired. But an uninterruptible power supply system can keep your computer as well as other electronic accessories away from any kind of power anomaly. However, uninterruptible power supply system’s cost is a bit higher than other power supply options, but they keep the computers and other electronic appliances humming from a few minutes to a full workday, even when the rest of the city goes dark.

Invest in uninterruptible power supply units instead of investing in repairs

You are a heavily computer-dependent businessman; and you have lost a few hours of work due to power cut or any kind of power fluctuation. You should consider investing in an uninterruptible power supply because it provides continue power and may help to keep you away from some loss that may occur because of power fluctuations. For each expensive electronic device you own, including audio system, television, home computer and refrigerator, UPS units are essential. Each uninterruptible power supply unit provides surge protection and its built-in batteries can immediately provide electrical energy in the occurrence of a power failure. Above all, such a device can protect data stored in the memory by keeping the flow of electricity until the computer can be turned off.

Uninterruptible Power Supplies – Installation Options

Single UPS installation

As the description implies this represents a single uninterruptible power supply installation comprising of the UPS and battery where the battery can be internal or external and consist of single or multiple strings. Multiple strings can increase the autonomy and also provide greater security of load in the event of a utility mains failure.

It should be noted that when the load has been transferred to the maintenance bypass mode it would be unprotected in the event of a utility mains failure.

Hot Standby UPS Installation

This installation uses two UPS modules, referred to as a UPS System; one (A) is directly coupled to the load, the output of the second (B) supplies the reserve input of A. Therefore if UPS A inverter fails the load is switched to the inverter output of UPS B and is still protected in the event of a utility mains failure. Equally either UPS can be switched to the maintenance bypass condition with no loss of protection to the load in the event of a utility mains failure. This is used when either the UPS or Generator power protection system are serviced as part of a regular maintenance regime.

Parallel Redundant UPS Installation- N+1

This installation can consist of up to eight modules and can be complete with a static switch module. This type of installation is designed to ensure that when fully loaded there is sufficient capacity to remove one module from service either for repair or maintenance without altering the integrity of the system. The added advantage is that the system with support an overload situation where redundancy is lost.

Parallel UPS Installation- Sharing the critical load

This installation consists of two or more, normally up to a maximum of eight modules dependent upon UPS manufacturer, to support the load. The number of modules is designed to support the load and can be a convenient method of installation where one module on its own may be too large to physically fit in the desired location. Also, as in the parallel redundant installation, providing the number of modules has not exceeded the manufacturer’s design requirements modules may be added as the site load increases.

It should be noted that it is not possible to parallel all types of UPS systems and that the individual modules need to be the same make, module and capacity and will require additional circuitry to provide the parallel control.

Disaster Preventative installation

This usually consists of a substantial UPS system backed by a diesel Generator

Remember, PowerContinuity Means Business Continuity. To ensure that failure is not an option, always take into consideration: is your power protected? If not, what steps should I take to ensure that it is?

For further information regarding uninterruptible power supplies, diesel generators, power protection or any other related power query, please visit our website at http://www.powercontinuity.co.uk and/or give us a call on 0845 055 8455. Call or visit us now and find your solution. Your power – we protect. Power Continuity.

Uninterruptible Power Supplies Alarm Monitoring and Control

Uninterruptible power supplies (UPS) are sophisticated, microprocessor-controlled systems, capable of providing a range of alarm notifications and real-time monitoring information at local, network and remote site locations.

 

This is important because it offers peace of mind and negates the need for ‘warden-type’ manual inspection of power protection equipment. However, monitoring for alarm conditions is required. The beauty of today’s UPS equipment is that it can now be carried out at one location, either centrally in-house or off-site at a specialist UPS monitoring provider. Many leading power protection manufacturers, such as Riello UPS, provide this type of service. It often means an engineer can be on-site and have equipment repaired, checked and running before the client is even aware of a problem.

 

The decision not to outsource uninterruptible power supply monitoring must be reinforced by the provision of dedicated monitoring personnel in-house whose responsibility it is to monitor and respond to UPS alarms. Failure to act in a timely and appropriate manner will significantly reduce system resilience. Typical examples include failure to notice that a UPS is operating in bypass mode or that there is a failed battery in a battery string (note: a UPS battery string is only as strong as its weakest battery).

 

The advent of Html capability in the software arena has enabled modern UPS manufacturers to integrate sophisticated onsite and remote monitoring capability within their hardware. In fact, modern systems enable remote 24/7 monitoring (either by the client or at the manufacturer’s facility) of all critical UPS, generator, air-conditioning and fire suppression equipment. As well as alerting system managers to problems as they arise, integration of monitoring functions into existing infrastructures gives businesses valuable early warning of impending power and other equipment failures that actively increases profitable uptime.

 

Most UPS are available with software packages that monitor mains voltage, UPS load and battery charge as standard, as well as proprietary monitoring and control software, which allows remote interrogation of UPS logs and operating parameters to help diagnose alarms and faults. When instructed to do so, UPS software can remotely perform automated and controlled shutdown of valuable equipment – ensuring hardware protection while freeing personnel for other tasks during power continuity incidents.

 

Types of alarms include:

 

Audible Alarms: audible signals are generated from within the UPS or a connected remote status panel and may be coded, using varying lengths of sound, to indicate specific alarm conditions. Audible alarm signals will remain ‘on’ until the condition is rectified or the alarm is acknowledged and silenced.

 

Visual Alarms: light Emitting Diodes (LEDs) provide a basic form of visual alarm notification. They may be single or multi-coloured and indicate the status of the UPS by employing one of three modes: on, flashing or off.

 

Some UPS utilise Liquid Crystal Display (LCD) with push-button controls to provide a slightly higher level of visual alarm capability. In this case, the user can scroll through a menu of information (measurements and logs).

 

The most sophisticated level of visual display is a full front-panel graphic-type, which typically consists of multi-character back-lit lines that display information in alpha, numeric and symbolic formats, either as text, alarm codes, graphics or a combination thereof.

 

Remote communication can utilise one of several protocols to provide data-exchange between an application and its UPS: serial connection (including RS-232), Simple Network Management Protocol (SNMP), MODBUS/JBUS or Profibus.

 

A range of UPS monitoring packages are available from UPS suppliers – from simple installation software designed to run on laptops, PCs and PDAs to more sophisticated monitoring and control software that runs on an enterprise server (whether Microsoft Windows, UNIX, Mac, HP and many others) and provides a host of information from UPS operating conditions to WAP availability.

 

There are two common approaches to monitoring and control by uninterruptible power supply manufacturers: centralised and decentralised. Centralised is where a specified server is used to control the orderly shutdown of the mixed platform network. Decentralised is where each individual server or PC runs its own copy of the monitoring software and controls its own shutdown procedure. The centralised approach is the most straightforward and least expensive to install but it can introduce a single-point-of-failure into the system. Should the control server hang and fail to shutdown the rest of the routine will be disrupted leading to potential data loss and a system-wide crash. With the decentralised approach, if one server or PC fails to shut down, the problem is isolated, thus achieving a higher level of system resilience.

 

The human instinct upon hearing or seeing an alarm is often to ignore it but planning how to monitor uninterruptible power supplies and associated alarm signals, and conceptualising appropriate responses, is an important aspect of a power continuity plan. If you want to go into it in more detail, there is a whole chapter devoted to it in The Power Protection Guide.

Uninterruptible Power Supplies- What Are Their Components?

Rectifier : this part of the UPS converts the incoming alternating current (ac) supply to direct current (dc) and can provide charging current for the battery and also the supply requirements for the inverter.

Charger : in a number of UPS systems due to the nature of their design a separate battery charger is used, this is more common on sub 60kVA UPS systems and is very common on small sub 3kVA units.

Battery : this is the power storage section and is kept charged either by the rectifier or a separate charger. Its storage capacity is generally displayed, as AH (ampere hour), which is the number of amperes of current that the battery can supply for an hour. There will be a number of limiting factors depending upon the application, typically if the design calls for a short autonomy (length of time the battery will support its load for), the batteries can be discharged to a lower level, in the case of emergency lighting where there is a requirement for a long autonomy the battery will not be allowed to discharge so far. These conditions help to allow the maximum design life of the battery to be achieved.

Inverter : this section of the Uninterruptible power supply provides an ac output to the load which is in phase with the input mains supply. Due to the number of conversions (ac to dc to ac) and the filtering involved it can be termed as a ‘clean supply’.

Static Switch : this circuit can be as simple as a relay or more commonly using thyristors, its purpose is to switch the load between the inverter and the utility mains supply. As has been previously mentioned the output of the inverter is in phase with the utility mains supply so that any switching between the two will be virtually seamless. This arrangement ensures that if the inverter experiences an overload situation, due to its extremely fast over-current detection circuits it will transfer the load to the more resilient mains supply. A typical example would be when a server rack is switched on, the inrush current, depending upon the size of your uninterruptible power supplies , could cause the transfer to the utility mains supply, and once switched on the load will transfer back to the inverter providing the inverter has sufficient capacity to support the load. Also a fault on the inverter will cause the load to be transferred, again virtually seamlessly; it would be unusual for any loss of load to occur during these conditions.

Maintenance Bypass : more typically found in UPS systems with a capacity of 6kVA or greater. This arrangement allows the load to be transferred under controlled conditions to the utility mains and the UPS to be shut down without loss. Normally carried out for routine UPS maintenance or UPS repair.

External Maintenance Bypass : the installation of an external maintenance bypass can allow the UPS to be removed/replaced without interruption to the load, also, if the actual maintenance bypass is fed from a separate supply it can allow load testing in the case of a major UPS repair and/or checking of the autonomy under simulated load conditions while the site load is being supported by the external maintenance bypass circuit. This is often used when allowing the UPS System to be bypassed onto standby diesel generator power. Alternatively, when batteries are replaced and removed, it can only be done by placing the uniterruptible power supply into external bypass.

Understandign Rotary Uninterruptible Power Supplies


More than ever, today’s uninterruptible power supplies (UPS) must be highly reliable and cause as little disturbance as possible upstream and downstream of their supply. Some manufacturers believe Rotary UPS to be the answer but others disagree, stating that new, improved designs of static online UPS make the added expense of Rotary UPS unjustifiable.

What are Rotary UPS? Rotary UPS are mechanical uninterruptible power supplies that convert Kinetic energy into electrical energy to power connected loads. There are two competing designs: Rotating Transformer, based on a regulated isolated rotating transformer; and Induction Coupling, comprising a diesel engine, two-speed concentrically-mounted induction coupling and alternator.

Whatever their design, Rotary UPS start at around 500kVA in size and range up to 2MVA (or more) when configured in parallel operation. For this reason, unsurprisingly, their application is reserved for large installations.

Compared to a static online uninterruptible power supply, manufacturers argue, Rotary UPS generate little in the way or harmful harmonics and can achieve higher MTBF (Meantime Between Failure) values. Harmonics can result in poor power quality, which can be as hazardous to critical equipment as a partial or complete mains supply failure. It can lead to intermittent data corruption and hardware failure.

The actual quality of mains power supply is measured in terms of its waveform, voltage and frequency and the presence (or not) of a variety of power problems including blackouts and momentary interruptions. Harmonics are voltage or current waveforms, the frequencies of which are multiples of the fundamental. In Europe this is 50Hz (50 cycles per second) and the multiples are ordered into a specific sequence. For example, the 2nd harmonic is 100Hz (2x50Hz), 3rd harmonic 150Hz (3x50Hz) and so forth.

MTBF is a standard indicator of the reliability of an uninterruptible power supply. It represents the average operational time between powering-up and system shutdown due to failure. The figure is usually presented in hours.

Rotary UPS manufacturers also believe their machines to have better fault clearance capabilities and that they are more suitable to loads with a leading power factor. A typical example of this is high-end server loads, such as Blade servers, which have a modular electronic circuit board often dedicated to a single application and housed within server chassis. Blade servers allow more processing power within less rack space than traditional or older server designs. They are being widely adopted within large data centre and telecommunications environments.

Loads, like Blade servers, with a leading power factor have a current waveform that ‘leads’ the voltage waveform by a factor equal to the reactance of the load.

Rotary uninterruptible power supplies offer a number of significant disadvantages too. A far higher capital, installation and environmental cost, for example, which can be as much as 40% higher than a comparable static online UPS design.

Higher Costs and Complex Installation

Installing Rotary UPS is much more complex than a static online UPS. They are a motor generator-based device and their installation presents high ventilation, vibration, noise and removal of exhaust gas issues. Some Rotary UPS designs operate at 30dBA higher noise levels than static online designs, which can cause noise pollution on site.

Increased Size and Weight. Rotary uninterruptible power supplies are heftier than their static online cousins and can demand as much as 20% more footprint area within a plant room or dedicated UPS area. This also makes system expansion difficult.

Increased Service Costs. As a mechanical device, Rotary UPS contain bearings in their workings, which require lubrication and this can make them sensitive when operating in Ambient temperatures. As a result, they can require more frequent maintenance and have a higher MTTR (Meantime to Repair) than static online designs. MTTR is a measure of the average time it takes to return a UPS to normal operation from shutdown in the event of a system failure. As Rotary UPS contain many bearings, their average MTTR is higher as these can take days to replace.

Static online UPS designs offer many advantages over their Rotary counterparts. Firstly, they are far less expensive to install and maintain and can be easily used in parallel and redundant configurations to increase reliability and resilience and improve MTBF. Manufacturers have also made great strides in mitigating harmonic pollution in uninterruptible power supplies with the inclusion of rectifiers and filters. They are also introducing designs specifically for high-end computing environments, that offer extremely high reliability, cost-effectively, but with the minimal footprint and ability to support leading power factor loads and minise harmonics.

The greatest advantage of a static online uninterruptible power supply over a Rotary design is their modularity and flexibility. It is far easier and cost-effective to expand a modern static online UPS design by adding another module into the parallel system, for example, than it is to rip-out-and-replace a huge, noisy Rotary unit.