In today’s world of high-speed technology and usage of sophisticated equipments, uninterruptible power supply is most essential one. The increased usage of electronic and other sophisticated equipments such as Computers, Audio System, Video Systems, Medical and Air Conditioners have brought necessity of using UPS, Inverters and Stabilizers.

What is UPS?

An Uninterruptible Power Supply or UPS, is a device or system that maintains a continuous supply of electric power to certain essential equipment that must not be shut down unexpectedly. The equipment is inserted between a primary power source, such as a commercial utility, and the primary power input of equipment to be protected, for the purpose of eliminating the effects of a temporary power outage and transient anomalies. They are generally associated with telecommunications equipment, computer systems, and other facilities such as airport landing systems and air traffic control systems where even brief commercial power interruptions could cause injuries or fatalities, serious business disruption or data loss.

Generally, nine kind of power problems that a UPS may encounter. They are as follows:

• Power failure.

• Power sag (under voltage for up to a few seconds).

• Power surge (over voltage for up to a few seconds).

• Brownout (long term under voltage for minutes or days).

• Long term over voltage for minutes or days.

• Line noise superimposed on the power waveform.

• Frequency variation of the power waveform.

• Switching transient (under voltage or over voltage for up to a few nanoseconds).

• Harmonic multiples of power frequency superimposed on the power waveform.

Line-interactive

In the Line Interactive UPS design, the battery-to-AC power converter (inverter) is always connected to the output of the UPS. Operating the inverter in reverse during times when the input AC power is normal provides battery charging.

When the input power fails, the transfer switch opens and the power flows from the battery to the UPS output. With the inverter always on and connected to the output, this design provides additional filtering and yields reduced switching transients when compared with the Standby UPS topology.

In addition, the Line Interactive design usually incorporates a tap-changing transformer. This adds voltage regulation by adjusting transformer taps as the input voltage varies. Voltage regulation is an important feature when low voltage conditions exist, otherwise the UPS would detect a power failure and switch to battery powered mode. Eventually the battery might become discharged and fail to power the load. Additionally, more frequent usage of the battery could reduce battery life or cause premature battery failure.

The ability to correct low or high line voltage conditions make this the dominant type of UPS in the 0.5-5kVA power range.

Off-line UPS

Meaning that the battery is not engaged until a power outage occurs, offering level 1 protection against power failures only. These are the cheapest variety of uninterruptible power supplies and are intended only for the home user.

On-line UPS

Online UPS converts AC power to DC and then converts the DC back to AC to power the connected equipment. The batteries are directly connected to the DC level. This effectively filters out line noise and all other anomalies from the AC power for level 9 protection. An additional benefit of this technology is in the continuity: in all 9 problem conditions, the system remains in the same operating mode. Relative to other UPS topologies there are efficiency losses due to the double conversion of all of the power the load requires. Technological improvements have resulted in efficiencies of 94%, which gives this technology some advantages over other types that offer fewer modes of protection for the sake of 1 or 2% more in efficiency in some modes.

Main areas where UPS must be used

Computers, Electronic Typewriters, Life Saving Emergency Equipments in ICUs, X-Ray Machines, Medical Monitors, Field & Lab Instruments, Communication Equipments, Electronic Cash Registers, Telephone Exchanges, Fax, Photo Typesetters, Tele-Printers, Security Systems, etc.

With hands on experience over a decade, KUMARAN ELECTRONICS producing UPS systems both On-line and Off-line (Line-Interactive) ranges from 0.5 KVA to 30 KVA capacities with the brand name KELTECH® (To download the brochure click here).

Special features

• Automatically switches to backup mode without power break in zero time, ON-LINE.

• Built-in Voltage & Frequency Stabilizer to supply regulated 230V, 50 Hz. +/- 2%.

• Very high isolation between Input & Output to filter EMI /RFI.

• Computer - grade Clean, Regulated & Filtered continuous non - beak Power supply.

• Automatically charges batteries, protected against under / over charge.

• Silent, sleek, compact, light weight, aesthetic design for desk top use.

• Ample overload capacity to handle start - up surges.

• Maintenance free batteries.

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