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I Have The Power

Team CHIP | 29 August 2009

UPS COmparison

I Have The Power

These UPSes can power four to five average desktops for around half an hour. Let's see which one outperforms the others.

 By CHIP Test Center

Power shortages are all too common, and stable electricity is a major necessity. Power conditioning is essential for electronic equipment like TVs and refrigerators and more importantly computers as they are most affected by low voltages, high voltages, surges, spikes and black-outs.

Metros like Mumbai experience minimal power failures, due to which an uninterrupted power supply unit (UPS) is not really required. A voltage stabilizer can take care of small instabilities and surges but is of no use when there is a power failure that can ruin a day’s work on the computer, cause system crashes and hardware failures resulting in permanent damage and corruption to data. Deploying a UPS will give the user the five minutes of emergency power he or she needs to save data and shut down the system.

A UPS functions like an inverter—converting DC voltage (stored in rechargeable batteries) to AC voltage. These batteries are charged when input power is available and are kept ready in case of a power failure. A basic inverter supplies unfiltered power, which can damage electronic equipment. A UPS can filter out spikes and surges and supply refined stable power during power failures, ensuring clean power reaches the equipment and there is enough time to shut down the system.

Online, Offline and Line-interactive UPSes are available in capacities from 500 VA to 10 KVA and beyond. Online UPSes are cost the most as they supply the purest form of power. An entry-level office PC uses around 150 Watts, while mid-range to high-end gaming machines can use 450–1,500 Watts. A 600 VA UPS can power an entry-level system for around 15–20 minutes.

If the connected load is similar to the power rating of the UPS, the maximum time available will be about five minutes. The power consumption should be calculated before the UPS is bought. Always opt for a UPS with at least 100–150 VA more than the power rating of the connected load. Extra batteries, if supported, can be added externally to the UPS to increase the backup time.

An average SOHO setup would have  three to four PCs, a printer and an Ethernet switch, making the power consumption not more than 900–1,000 Watts. We've chosen to test 2,000 VA (2 KVA) uninterrupted power supplies which are sufficient for these types of SOHO setups with additional room to add one or two more computers.

Maintainence Tips 

Keep your UPS clean at all times. Don't let dust settle on the external battery, terminals and the vents of the main unit.

Don’t install, place or stock a UPS under stairs, in AC ducts, lofts, meter rooms, sealed cabinets, etc. Allow air to circulate around it to keep its internal temperature lower.

Don't expose the UPS or the batteries to direct sunlight or subject them to excessive heat, water, flammable or corrosive agents.

The life of the batteries will be extended if they and the UPS/inverter unit are kept below 25 degrees.

Draining the batteries completely once every 15 days will also extend their life. This can be done by running the UPS on battery by switching off the main supply, creating a fake power failure.

Ensure that no are items kept on the UPS or the batteries to avoid any fire hazards.

Inspect the external batteries for any leakage/ damage at least every 15 days.

Charge a new UPS for 12–14 hours before its first use.

Don't connect equipment to the UPS in excess of its rated load capacity.

When power fails, disconnect unwanted or unused equipment like printers, modems, chargers, scanners, etc. The less there is connected to the UPS the more battery backup time.

LCD monitors and energy efficient components and peripherals can increase battery backup time.

Don't use equipment like fans, refrigerators, air conditioners, etc on a UPS designed for computers.

Use proper earthing and check for any loose contacts before using a UPS. If you find anything abnormal in the UPS in terms of excessive sound, heat or vibrations, switch it off and contact the UPS service technician immediately.

Learn the beep codes as per the user manual. This will help you detect faults in the UPS.

Do not try to connect/disconnect any battery terminals yourself. Contact a service engineer only.

Have a maintenance engineer inspect and service the UPS once every six months or as per the UPS manufacturer’s advice.

Powercom KAL2000AP

The Powercom KAL2000AP is a straightforward line interactive UPS, which does not need any type of user intervention. The front panel has one power switch and five LED indicators that show at a glance the present condition of the UPS . These LEDs reveal the status of the UPS (AC mode or battery mode), Buck and Boost or the power condition (over/under voltage), battery mode and battery fault. The buck and boost feature automatically activates the built-in automatic voltage regulator (AVR) to correct input voltage (from the AC or battery) ensuring that the load receives a constant voltage supply. The batteries are not in-built, and have to be connected externally. The battery unit comprises of four 12 V, 7 AH maintenance-free dry batteries. Additional batteries can be connected if the required battery operation time for the load needs to be higher in case of a power failure.

This UPS features an RS323 interface and is bundled with a program called ‘UPSMON’ which allows the user to monitor and control the UPS from the computer itself. The features of the software include maintenance of the batteries which can be automated once a week for longer life. The UPS also features an Ethernet line filter to prevent surges. This simple UPS can be deployed for small servers and home computers. With higher capacity batteries, one can get greater battery backup time.

Powersafe UPS 2000L

A long lasting UPS in a small package, this line-interactive model from Powersafe is as small as a net-top PC and runs off two external batteries. This small unit along with two 40 AH batteries hooked up to two entry-level computers with LCD monitors gave us a good 130 minutes of runtime in our tests. The unit is comparatively small and light and can be placed on a desktop along with the computer, but that would completely depend upon the size of the batteries installed as the batteries would take up a lot of space with their cluttered wires coming in the way.

The UPS 2000L does not have any control panel on the front bezel, nor can it be controlled or monitored via any software as it lacks an RS232 interface. The front panel of the Powersafe UPS 2000L features just one single power switch and three LED indicators for online, battery and fault/overload modes. The UPS 2000L is used with two 40 AH batteries and can effortlessly power up to 12 machines for as long as 5–7 minutes, which is sufficient enough for saving and shutting down the machines in the event of a power failure. The compact UPS 2000L from Powersafe is great as an emergency power unit and can be considered for small environments such as shops, offices and cybercafés as it can easily sustain up to an hour of power for around two to three machines to finish work and shut down.

Powercom VGD-2000L

An online UPS from Powercom, the VGD-2000L is rugged and is a single unit with built-in batteries. It can be monitored and controlled via the bundled software and the front digital control panel which features an LCD display indicating input/output voltage, frequency levels, etc. The control panel also has the usual LED indicators for the overload, power and battery status. Six 12 V, 7 AH maintenance-free dry batteries make up the battery pack inside the unit, but if you need additional power, you would need to connect higher rated batteries to the unit externally. In this case, the internal batteries should be replaced by a high capacity battery charging unit, which would be needed to charge the external batteries. The UPS also features an Ethernet line filter to safeguard your internal LAN from possible surges from an external WAN. The back panel has eight 5 A power outputs to connect computers or peripherals and one 15 A connection to route the power to external power strips in case the computers are not close to the UPS unit. Other features are an emergency power off and a circuit breaker to prevent damage from extreme over-voltages. A slot on the rear can accommodate an optional SNMP interface circuit to control and monitor the UPS via the local network. This UPS is great for servers and small offices as it can be automatically controlled via the software control panel.

Eaton Powerware 9130

The heaviest UPS of the lot, the Eaton Powerware 9130 is an online UPS and is quite similar to the Powercom VGD-2000L. It is almost the same size as a regular ATX computer cabinet. It has built-in batteries for backup which can be extended (externally) by adding an internal charger unit for larger capacity batteries. The control panel here features complete control and monitoring of the UPS, which eliminates the need for the software, (which is not bundled anyway). If you do get the software, you would get more stringent security features to help turn off the connected computer when the power in the batteries is almost drained.

The VGD-2000L can be monitored and controlled using an RS232 or a USB interface. The control panel features a dot matrix LCD display which indicates battery charging time, power level, amount of load connected, input power condition, automatic battery maintenance, approximate battery backup time on connected load, and a lot more. The UPS employs a couple of intake and exhaust fans to keep the internal components cool, but these fans are quite noisy and can be disturbing. The rear panel also features a slot for an optional SNMP interface to control the UPS from a remote location using Ethernet. This UPS could be deployed for unattended servers if the control software and interface cable are installed, and is good for small offices.

Powersafe PS-2000 ONL

Providing great value for money, we would suggest investing in the Powersafe PS 2000 ONL UPS. Cost effectiveness and maximum battery run time are what a UPS should offer, and this one left all the competition way behind in the tests with almost five hours of power. This Powersafe UPS unit is an online device with four 40 AH external batteries connected to it. The batteries are fairly large and heavy, but when maximum power time is of a higher priority, the space occupied by the UPS unit can be justified.

This model is a simple straightforward unit with just a single power switch present on the front panel. Six LEDs additionally make up the front panel which inform the user about the status of the UPS—online, battery and fault modes. The other three LED indicators inform users about the battery power level when in battery mode. The UPS does not feature a computer interface (RS232/USB), and so it cannot be controlled via software. The Powersafe PS 2000 ONL can be best deployed for computers being used in shops and small office environments in areas more prone to power cuts. It would  have been great had the company added an RS232 interface. It would only bring additional value to their UPS. The Powersafe PS-2000 ONL is meant for small environments and for unattended servers. The superb battery power time is sure to impress.