How does a UPS work

With such erratic weather patterns of late - immense heat, to thunderous storms - the only thing predictable is the protection a good UPS can provide you and your equipment.  A UPS or uninterruptable power supply provides emergency power to a load when the input power source or mains power stops or fails. It is basically a battery backup for your systems. This will allow for the safe, orderly shutdown of a computer and connected equipment will and provide immediate protection from input power interruptions by providing energy stored in either the battery, flywheel, or supercapacitors. The size and design of a UPS will determine how long it will supply power for.

UPS’s are manufactured to protect single PCs to large scale operations, and everything in between. The protection of computers, data centre equipment, telecommunications equipment, and electrical equipment where a power interruption could cause potential injury, business interruption or data loss is the main focus of a UPS.

UPS Functions:

The UPS is utilised for when one or more of the following incidents occur:

• A sustained overvoltage

• Voltage spikes

• Voltage sags

• High-frequency noise injected into the network by nearby equipment

• Mains frequency instability

• Harmonic distortion

Typical UPS types: 

There are 3 main categories of UPS’s in today’s market. These are described below:

ON-LINE UPS – also known as double-conversion is where the batteries are always connected to the inverter. This eliminates the need for power transfer switches. In the case of a power loss, the rectifier drops out of the circuit whilst the batteries keep the power at a steady position. Once the power is restored the rectifier kicks back in carrying the majority of the load and will begin to the charge the batteries.

The advantage of this type of UPS is that it provides an electrical firewall between the incoming power and sensitive electronic equipment.

This type of UPS is designed for an environment where electrical isolation is required or for equipment that is oversensitive to power fluctuation. In addition, this type of UPS is very effective in a noisy power environment, when power outages, fluctuations, sags are frequent, and for the protection of sensitive equipment.

OFFLINE UPS – also known as standby, this UPS offers basic surge suppression and battery backup. In a situation where protected equipment is connected directly to the incoming utility power and a situation occurs where incoming voltage falls or rises above a predetermined level, the UPS will intervene by turning on its internal DC-AC inverter circuitry and mechanically switches the connected equipment to its DC-AC inverter output.

This type of UPS is designed for a personal computer environment.

LINE-INTERACTIVE – This type of UPS operates similar to the offline UPS however has the added feature of a multi-tap variable-voltage autotransformer. This style of the transformer can add or subtract powered coils of wire. This will increase or decrease the magnetic field and the output voltage of the transformer. A line-interactive UPS sustains continuous overvoltage and under voltage surges without consuming battery power.

There are numerous additional models of UPS’s in the market that are more costly and complex in operation than described above.

Determining which type of UPS required depends on a full understanding of what equipment you are intending to protect in the event of overvoltage, under-voltage, power loss, power inconsistency, sags, spikes, and noise occurrences.

The basic role of the UPS is to provide a short -term power when the input power source fails.

In environments where operations are critical, the correct UPS for the application is a must to ensure the people and equipment protection is provided.