SOHO/OFFICE/HOME: Inverters are now more intelligent, feature packed and user friendly

The increasing power deficit throughout the country is one of the major factors driving the growth of the inverter industry in India, which is a highly fragmented, competitive and growing market, with the presence of several branded and unbranded products.

By Srabani Sen

Tuesday, July 12, 2011: For most businesses, it is critical to have an office power backup solution in place, as a power outage means loss of revenue and potential sales. There is often a need for emergency power backup for critical appliances in offices such as computers, printers, scanners, switchboards, mobile telephones, lighting, etc.

According to Frost and Sullivan, the Indian power inverter market was estimated to be worth approximately Rs 20,000-22,000 million in 2010-11, in terms of revenue. It has been projected that the inverter market will exhibit double digit growth rates during the next three to four years. This is likely to be the result of a steady demand from the domestic, small office home office (SOHO), small and medium enterprises (SME), commercial, industrial, and other sectors.

WHAT’S AVAILABLE IN this segment

Most innovations in inverters for SOHO and home are related to increasing efficiency and stability. This helps in saving power as well as the environment. Innovations are also taking place to enable inverters to charge fast, thus enhancing the longevity of the battery. Steps are also being taken to go for higher MTBF (mean time between failure) batteries, which save manhours.

Earlier, inverters were manufactured with quasi sine wave output but now they are being manufactured with the latest digital signal processing (DSP) based sine wave output. MOSFET based and IGBT based sine wave and high frequency transformerless inverters are also in demand, as they are small and occupy less space. The size of inverters is being reduced continuously due to advances in technology. Another change is that, earlier, inverters were usually hidden away somewhere in the office. But now manufacturers are coming up with aesthetically designed units, prompting users to display them.

Today, there is an attempt to build in UPS mode, which reduces the voltage window within limits and is acceptable to most SMPS. There is also an attempt to reduce the transfer time to the acceptable limit of 19 minutes. These two features help in making 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 users’ convenience, enabling them to be aware of various environmental conditions.

Generator compatible inverters are the latest products in the power backup industry as they not only save power and reduce pollution but also cut down on diesel costs. These inverters also provide relief during the switch over time from the main power supply to the generators. These inverter/generator combinations facilitate power savings of up to 50 per cent.

Microtek International Pvt Ltd has a complete range of SOHO, high end and sine wave inverters in the 2.2 kVA to 10 kVA range, which are suitable for big and small offices. “These can even run air conditioners, LCD TVs, photocopying machines, etc,” informs Manoj Jain, vice president, Microtek International.

upsINVERTER.com’s sine wave combo UPS system, which is based on microcontroller digital technology, has an inbuilt AVR that stabilises the input AC mains. “Its highlight is a high frequency pure sine wave UPS system, and it takes up very little space; hence, it is suitable for offices where there is a space crunch,” says Yogesh Dua, director, upsINVERTER.com.

American Power Conversion (APC) offers pure sinewave inverters in home/SOHO/office segments. “Customers prefer quality of sine wave output inverters as these are far more quieter than square wave/semi square wave/stepped approximation to sine wave,” says Gaurav Burman, director, transaction business, American Power Conversion.

Su-Kam has recently introduced the Shiny series of pure sine wave UPS (it also works as an inverter) systems. In the digital segment, it has the Shark range to supplement Shiny. Both these products can be used effectively at homes and offices.

Su-Kam’s DSP based sine wave inverters in the Colossal series, which provide stabilised pure sine wave output, are also suitable for all types of commercial establishments and are capable of running elevators and welding arches as well. The Colossal range comes in the 5-100 kVA range. The company has also created a pocket friendly 100 VA home UPS/inverter, which is affordable for lower income groups. At the other end of its product range, it has refined the 500 kVA inverter for big offices.

“Su-Kam was the first to introduce DSP based sine wave inverter systems, specially designed for heavy duty retail and telecom applications, where we have provided an advanced solution as an alternative to generators,” informs Kunwer Sachdev, founder and managing director, Su-Kam Power Systems Ltd.

Luminous’ latest offering for the SOHO segment is its Shakti Charge brand of inverters, which are custom made for rural power requirements. It has also introduced the Bravo Vx and UPS LB+ Vx, customised for areas facing 6-10 hours of power cuts and Bravo Lx UPS LB+ Lx, customised for areas facing not more than 6 hours power cut, both powered by LT500 tubular batteries, specially designed for such requirements. Luminous also has a very efficient higher kVA long backup UPS/inverter range to cater to higher power requirements in offices.

Truepower International Ltd has currently launched a solid state pure sine wave UPS system that can be used as an inverter as well. The range starts from 1500 VA to 15 kVA. The transfer time of the UPS system is less than 10 milliseconds and can safely run computers without any rebooting. This UPS-cum-inverter can provide three to four hours of backup. These are suitable for SOHO as well as medium and big offices. “This unique device is used for fast changeovers without any spark and noise,” says Ravi Mundra, CEO, Truepower.

Convergence Power Systems Pvt Ltd offers dual charger inverters for the SOHO and the home segment, which have a utility mains charger and a solar charger. “This solar cum utility power (dual charger) inverter for offices, ranges in capacity from 600 VA to 10 kVA,” points out Sree Kumar, director, sales and marketing, Convergence Power Systems Pvt Ltd. It also offers DSP sine wave and DSP sine wave dual inverters and microcontroller based inverters.

Lzen Electronics India’s ICON DSP-based sine wave inverter with pure sine wave output is suitable for all types of offices, and is capable of running everything—from lights, fans, refrigerators, computers, fax machines and printers, to microwaves, air conditioners, lifts, etc. “It is safe to run even sophisticated and sensitive office equipment. These inverters are energy efficient as the input efficiency is very high, which results in lower electricity bills,” says Manish Gupta, CEO, Lzen Electronics India.

Best Power Equipment India (BPE) offers full DSP controlled pure sine wave inverters in the 800 VA to 20 kVA range. “A high power factor with reduced distortions and better efficiency, along with the lowest possible downtime, are some of the innovations taking place in inverters for offices,” says Amitansu Satpathy, director, Best Power Equipment India.

TECHNICAL AND USER FRIENDLY FEATURES

In tune with consumer expectations, inverters are today more intelligent, feature-packed and user friendly. However, most manufacturers are doing mere cosmetic changes to their products, as inverters are very stable and their technology has remained nearly unchanged for years.

Power saving features

Keeping up with the demands of customers, manufacturers now offer inverters with green technology that have power saving features. Earlier, the efficiency of inverters was around 65-70 per cent but now they are being manufactured with more than 95 per cent efficiency. And more efficiency means more power saved.

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

Ravi Mundra explains that power factor correction technology is used in inverters for power saving. The charger efficiency is improved by applying signature charging, which is a completely automatic charging selection

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 gauge which features are important and 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 (AMPS x voltage = watts). It is wise to purchase a higher powered 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 that can be powered by the mains supply of 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.

The buyer must consider the energy efficiency (how much electricity is consumed during the use) of the inverter and the life of the battery. After sales support and the price received during disposal are some other key factors to be considered.

The inverter should provide protection against overload, low battery, short circuits, etc. Buyers should also check if the inverter can work with all types of batteries such as flat plated, tubular and valve regulated maintenance free batteries.

It is advisable to do a comparative survey before making the purchasing decision. Also, understand your power requirements.technology. In case of no load at output, the intelligent software inside the inverter senses the condition and goes into sleep mode (that is, the inverter stops discharging).

Microtek inverters have a ‘high grade low watt loss’ core in transformers, which minimises watt loss and makes the inverters energy efficient. APC inverters, on the other hand, offer triple stage charging, which consumes less power to charge. This also helps in charging batteries faster, and therefore, results in 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 discharged when the power supply fails. This switch has to be activated when the office is closed over the weekend. This feature helps conserve the charge on batteries, and therefore, saves power.

Su-Kam’s Colossal series delivers an output which is completely stable and distortion free—with total harmonic distortion (THD) <3 per cent. This power is actually purer than power supplied from the grid.

User friendly features

Inverter systems are now very user friendly. They are fully automatic with digital display meters for users to see the parameters and functions. Inverters with a one-touch switch for all settings and configurations are quite popular. In fact, after the installation of these inverters, users can relax. These units are also noiseless and pollution free. Some systems also come with graphical and LCD displays.

Su-Kam’s digital inverter ensures user selectable heavy duty charger options that charge the battery 40 per cent faster than ordinary models. Its graphical display with audible alerts makes it very user friendly. Moreover, it has the capability to be upgraded in the future through digital flash memory.

All Su-Kam UPS has patented fuzzy logic control (FLC) technology, which extends battery life, reduces water topping and saves electricity. This not only prevents deep discharge of the battery at a low rate of discharge, but also allows low battery water consumption and there is no continuous charging at high current. The company has also introduced a battery selection slider switch feature behind the system, which enables the customer to select different types of batteries.

APC’s new inverter range comes with a number of new and innovative features. Its fans and tubelights are quieter due to sine

wave output. Its multiple battery charging current selector switch can be slided to select the right charging current to match the battery size. This helps increase battery life. The LED user interface indicates faults related to wiring or the battery. The UPS/inverter selector switch can be toggled to change the output voltage range. In the inverter mode, the inverter will run on mains even at 100 V. This helps in regions where customers experience very low voltage conditions for extended periods. On UPS mode, the inverter has a more acceptable 190-260 V output that runs sensitive equipment.

Truepower’s Hulk solid state UPS system has a wide charging range and complete automatic charging selection technology, which has been introduced with GPM technology, making it easy to use. GPM technology protects the battery from overcharging in case of edging of battery.

Convergence’s inverters are fully automatic, making them very user friendly. upsINVERTER’s inverters are also completely automatic and they can even sense low voltage in the mains supply and short circuits. These products rarely require any human interface.

Lzen inverters are fully automatic with digital display meters for users to see all the parameters and functions, and these are controlled by just a single switch. The inverter system also has a high and low charging switch at the back, which can be selected by the customer, based on which mode the battery is being used. Another feature is the inverter mode switch, which allows the user to select the input voltage windows to run the equipment.

PRODUCTS AND THEIR FEATURES

Note: The names of the companies are in alphabetical order

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