Noisy generators giving way to inverters in offices

Noisy generators are giving way to inverters in offices. For most businesses it is critical to have an office power backup solution as a power outage means loss of revenue and potential sales. Emergency power backup is needed for critical appliances in offices such as computers, printers, scanners, switchboards, mobile telephones, lighting, etc. “You will be surprised to know that now high capacity inverters are being used for running lifts, air conditioners, air coolers, elevators and even telecom applications,” informs Yogesh Dua, director, upsINVERTER.com. “In small offices, it is used to operate Epbx, phones, fax machines, colour laboratory equipment, etc,” he adds.

By Srabani Sen

Tuesday, March 16, 2009: “Inverters are cleaner than DG sets in the sense that they do not produce smoke. They are also instantaneous as typical transfer time can be less than 19 minutes which is needed for PCs. Some of their features are almost like UPS. So, for SOHOs and SMBs use of inverter as the prime power backup device is advisable,” says Gaurav Burman, director, transaction business, American Power Conversion (APC). “A new application is solar inverter which is used as power backup device, converting abundantly available solar energy to electricity. In solar segment, there is another concept—grid tied inverters, which convert solar energy into electricity but feed it into the common grid instead of storing it in battery,” adds Burman.

Inverters can be used in offices that need to stay running for a shorter period of time. Running an inverter is not only a cost effective means of standby power but a fully automatic inverter can also provide a noise free environment.

Types of inverters required in offices

Both modified sine wave power inverters and true sine power inverters are used for office purposes. These are specifically designed and are ideal for charging batteries from either solar panels or external battery chargers.

Inverters come in many types and sizes. In addition to providing the alteration of one power type to another, they are constantly modified to provide better efficiency and stability. “Generally, inverters of 5-20 kVA are required in big offices and 800-1400 VA in small offices,” says R K Bansal, managing director, Uniline Energy Systems. Adds Sree Kumar, director, sales and marketing, Convergence Power System, “For small offices, domestic inverters up to 5kVA capacity can be used and for corporate offices, the requirement can go up to 100kVA industrial grade inverters.” Rakesh Malhotra, founder and managing director, Luminous Power Technologies Pvt Ltd, feels that for small offices, inverters from 3-10 kVA are sufficient but for bigger offices it should be anything between 15kVA and 100 kVA, depending on the load requirement. According to Dua, square wave inverters, quasi square wave or modified square wave inverters and true/pure sine wave inverters are ideal for big offices.

The DC-AC power inverter/battery charger combination can be used as an extended AC power supply system. Combination power inverters have built-in battery chargers and transfer switches, which make them affordable and hassle free solutions for uninterrupted power requirements, giving almost seamless power supply by switching over automatically.

The benefit of these power inverters over UPS systems is that you can size your own battery pack to get as many hours of backup as you need. They also have three times power overload surge ability which is absent in most online UPS systems. The combination power inverter/charger units can be used in conjunction with very small and much more affordable UPS units, for the likes of computers, which require a very fast switch over function so as not to lose any data.

What’s new and innovative

Today’s manufacturers are consumer-centric and aim to make products more convenient for consumers. With technology advancing at a fast pace, customers are demanding inverter solutions with advanced technology and desiring the most feature packed products, which is increasing the competition in the market. “Su-Kam’s DSP sine wave inverter Colossal series, with reliable, regulated and stabilised pure sine wave output, is a complete power generation system that is suitable for all types of commercial establishments and is capable of running everything from lights, air conditioners, lifts and elevators and welding arch in the most cost effective manner,” says Venkat Rajaraman, CEO, Su-kam Power Systems Ltd. “The Colossal series supplies pure power, which is 100 per cent safe to run even sophisticated and sensitive office equipment without any noise,” he adds.

Says Manoj Jain, vice president, marketing, Microtek International Pvt Ltd, “To compete in the market, we have a complete range of hi-end sinewave inverters and SOHO range of digital and sinewave inverters, which are most suitable for office applications and are totally safe for sensitive appliances. Microtek has actually made inverters energy efficient.”

Most innovations happening in inverters for offices are focused on increasing efficiency. This helps in saving power as well as the environment. “The latest in the market are of two types—mosfet based and IGBT based sinewave and high frequecy trasformer less inverters, which are small in size and occupy less space. We supply sinewave inverters with fast changeover time of less than 10 minutes, which can support PCs as well,” states Samant Choudhary, director, Samtek Electronics. Adds Sujeet Kumar, managing director, ACPL, “IGBT high frequency inverters are the suitable ones.”

ACPL supplies 2-5kVA inverters with provision of AC power supply charging as well as solar charging option.

According to Amitansu Satpaphy, director, Best Power Equipment India, high power factor with reduced distortions and better efficiency with lowest possible downtime are some of the innovations taking place in inverters for offices. “We offer full DSP controlled pure sine wave inverters from 800VA to 20kVA range,” he adds.

Luminous offers pure sine wave inverters that are available with UPS applications as well. “These combos can be used for running computers in small offices. We also have inverters ranging from 3-20kVA, depending on the load requirement of customers,” says Malhotra

Explains Bansal, “Earlier, inverters were manufactured with quasi sine wave output but now they are being manufactured with the latest DSP based sine wave output. We supply inverter systems to many corporates that run single phase as well as three phase AC. We also supply inverter systems for various applications like in Pizza Hut, which uses inverter systems as a substitute for generators. Our inverters are also used at the Taj Mahal, where generators cannot be used due to environmental issues.”

UpsINVERTER.COM’s pure sine wave inverter with automatic voltage regulator and Hi-Lite combo are ideal for office use, claims the company. The pure sine wave inverter is a safe combination of UPS, inverter and voltage stabiliser as it provides pure sine wave output and is powered by micro controller digital technology. “The Hi-Lite combo is a noiseless high frequency combo system, which has high computer compatibility. It is also powered by microcontroller digital technology,” says Dua.

“The current trend is the usage of sine wave industrial grade inverters in corporate offices. Usually, inverters are supposed to be hidden somewhere in the office. But not any more. Now the technology has advanced and manufacturers are coming up with aesthetically designed units, prompting users to display them. We have a range of inverters for offices including quasi sine wave 200VA to 5kVA, sine wave regular inverters of 600 VA to 5 kVA and industrial grade inverters heavy duty of 5-60 kVA,” says Sree Kumar.

“We have developed solar inverters, which is a boon for the Indian market as there are many places where people don’t get mains power to charge the battery. We have a wide range of input base inverter systems that can cater big power requirements. Our small GPH-UPS systems are intelligent enough to serve IT applications. Besides, we also have higher rating inverters and inverters for the telecom sector,” says, N K Verma, chairman, Parker Power.

“Essentially, most vendors are doing cosmetic changes in their products as inverters are very stable and their technology has remained nearly unchanged for years. So, we can say that solar inverters are the latest but till date they have limited business applications,” points out Burman. “There is an attempt to build in UPS mode which reduces the voltage window within limits and is acceptable to most SMPSs. There is also an attempt to reduce the transfer time to the acceptable limit of 19 minutes. These two features help in making the inverters compatible with PCs and servers in office environments. Besides this, some other features like load indication, battery charge indication and fault indication add to convenience of knowing various environmental conditions,” adds Burman. APC offers 1kVA- BI1000I inverter for offices. This inverter offers a pure sine wave output and uses two batteries (24V bus) to provide extended run time. As expected by most businesses, it offers load indication, fault indication and faster transfer times to add to convenience. APC is also working on identifying a lot of new product slots in higher kVAs to suit all kinds of business customer needs.

Power saving features

Keeping with the demand of customers, manufacturers now offer inverters with green technology having power saving features. “Earlier, the efficiency of inverters was around 65-70 per cent but now they are being manufactured with more than 90 per cent efficiency. And more efficiency means more power saving,” says Bansal. Agrees Malhotra, “These inverters have the latest technology to provide maximum output. However, 80-90 per cent of the time inverters run on the mains with more than 97 per cent efficiency.” Adds Sujeet Kumar, “Today’s inverters have strong battery charging management which consumes power only during charging. In case of solar battery chargers, considerable amount of power is saved.

Points out Dua, “High efficiency in DC to AC and AC to DC conversion, no-load shutdown, optimised battery charging management and low internal power consumption in parts like cooling fan, display, etc, are features that help in saving power.” Sree Kumar says, “The fuzzy logic technology makes sure of less power drainage during charging. The high quality transformer designs also ensure low load current.”

“Microtek inverters have high grade low watt loss core in transformers, which minimises watt loss and makes the inverters energy efficient,” says Jain. Adds Choudhary, “Samtek inverters have better input power factors which reduces input current. They also have better battery charging management which prevents over charging of battery.”

“APC inverters offer triple stage charging which consumes lower power to charge. This also helps in charging batteries faster, and therefore, an improved battery life. These inverters offer higher efficiency which leads to lower power losses when the battery is being charged and even when the battery is being discharged to provide power. All APC inverters come with an A-way switch which allows the batteries to be charged but not discharge when power supply fails. This switch has to be activated when office is closed over weekend. This feature helps conserving charge on batteries, and therefore, saves power,” states Burman.

“Su-Kam DSP sine wave inverter Colossal series produces pure sine wave. Digital signal processing (DSP), the world’s most advanced technology meant for high speed data processing, in conjunction with sine wave technology delivers output which is completely stable and distortion free—total harmonic distortion (THD) <3 per cent. This power is actually purer than power supplied from the grid,” says Rajaraman.

User friendly features

Inverter systems are now very user friendly which are fully automatic with digital display meters for users to see the parameters and function displays. Inverters with one touch switch that does all settings and configurations are quite popular. In fact, after installation of these inverters, users can relax. These units are also noiseless and pollution free. “Our systems come with graphical display and some with LCD displays,” adds Verma.

“Su-Kam’s digital inverter ensures user selectable heavy duty charger option that charges the battery 40 per cent faster than ordinary models. Its graphical display with audible alerts makes is very user friendly. It also saves space and has the option of castor wheel mounted trolley for easy movement. Moreover, it has the option of future upgradation capability through digital flash memory,” adds Rajaraman.

“Our inverters have very clear and easy to understand indicators. Our next generation inverters will incorporate even better user friendly features,” says Burman.

Cost of installation

Inverters are very cheap to install and maintain. Battery is the only item that needs constant topping up (which is actually very cheap too). A typical installation involves load separation (between heating or high load and lighting loads). Depending on how much cabling needs to be done, installation can vary. Yet, it is not very expensive. Most inverters do not need any maintenance after being installed and they could run their lifetime without any trouble.

According to Bansal, the cost of installation and maintenance of inverters mainly depend on their capacity. “But generally, the installation cost and maintenance cost are less than 10 per cent of the inverter cost,” he adds.

Malhotra feels that there is no cost involved in installing inverters if wiring is appropriate in an office. Adds Dua, “The installation does not require even power sockets or battery wires. It is quite easy and time saving with no cost at all.” Says Satpaphy, “Maintenance of these inverters is also free for two years as most manufacturers provide two year warranty.”

Customisation

In this competitive market, where every company is vying for a greater share, many provide services like customised solutions, which are not only profitable but also a good brand building strategy. “To grow and surge ahead, companies need to keep pace with the changing demand and do something out of the box which is not a run-of-the-mill job. We customise inverters to suit the Indian office conditions like power fluctuations, frequency variations, etc,” says Satpaphy.

“Luminous inverters up to 10 kVA have very low switching time, hence they can be used for computers. Higher rating inverters are unbalanced type. Considering inrush current requirement for motorised/lift load, we have 6kVA three phase to 150kVA three phase inverters,” informs Malhotra.

Adds Dua, “We can customise and put in time delays for air conditioners; cold start for IT applications; and high crest ratio for machine loads. Besides these, we can change the input DC voltage as per client’s requirements to make it more economical.”

“We offer solutions that can be customised to serve the interests of clients—small or large enterprises from diverse industries. Many customers cannot use standard products, so they look for customisation of products congruous with their requirements,” says Verma. “As per the requirements of our customers, we modify our batteries and inverters to provide better backup. Our inverters come with four different charging options and customers can use them as per their individual power conditions,” adds Verma.

“Currently, most customisation happens in the size of batteries attached with the inverters. This depends on the kind of load that needs to be supported and the run time required,” points out Burman.

After sales support

After sales service is an integral part of any company and is almost as important as the initial purchase. If properly handled, service can be the key factor of growth for any manufacturer. But if Ignored, it can cause a dent in the creditability of the brand. “For customers, exceptional service is a rule not an exception. Anything less, they’re ready to change their brand. That makes extraordinary service necessary, not just desirable.

“APC has one of the largest ASP networks that reaches every nook and corner of the country. This helps serve all customer requirements like installation support and even get faster product replacement in the unlikely event of product failure. Our call centres address every customer’s need. Besides this, APC offers four free preventive maintenances of battery to its customers. This helps save battery from dying early,” says Burman.

We give onsite services in all major cities,” says Satpaphy. Sree Kumar says, “We provide free onsite after sales support during warranty period and outside warranty period service is provided on call or after sales maintenance contract (AMC). But our service is very prompt.” Adds Verma, “We extend onsite services and our toll free number gives freedom to customers to interact with us for prompt service.”

Microtek provides after sales support through its vast service network of 35 service centres and more than 255 service points in the country. Malhotra, however, says, “Luminous has pan India after sales support, so it is not an issue for us.” Shares Dua, “We forge very less AMCs as our systems are very robust. It is once in a blue moon that we charge any customer for after sales service and it really pays off as customers remain happy that way.”

Buying tips

Purchasing inverters for offices may appear a simple task but when you go shopping, you come across a large number of choices. Sometimes it can be difficult to know which features are important and how you can choose the right product for your needs. While wattage, features and connections are obvious considerations, your final choice should take into account the inverter’s wave form output.

Once you have decided to buy an inverter, think about what power (wattage) it should be carrying. The total wattage is calculated as a product of current and voltage (i.e. amps x voltage = watts). It is wise to purchase a larger power inverter than you need.

When purchasing a modified square wave or a pure sine wave inverter, you must consider which appliances you intend to power? A pure sine wave inverter can power any device/appliance which can be powered by mains electricity—but a modified square wave inverter cannot. For example, desktop computers can be powered by a modified square wave inverter but the monitor may make an audible humming sound. It is advisable to do a comparative survey before making the purchasing decision. Also, understand your power requirements.

Electronics Bazaar, South Asia’s No.1 Electronics B2B magazine