Frequently Asked Questions

UPS stands for Uninterruptible Power Supply. It immediately provides power to connected equipment during a mains failure or power disturbance, ensuring continuous and stable operation.

Unstable power quality affects the reliability of computers and critical equipment. A UPS not only provides immediate backup power during outages, but also protects against wide voltage variations, delivers clean and stable power, and helps safeguard important data whether personnel are on-site or not.

There are three primary UPS topologies: Off-Line, On-Line, and Line Interactive. Each provides a different level of power conditioning and protection suited to different application requirements.

An off-line (or standby) UPS supplies power from its battery only when a mains power failure is detected. Under normal conditions, the connected equipment runs directly from the mains supply.

An on-line UPS continuously supplies power through its rectifier and inverter, providing a fully conditioned, pure sinewave output at all times. It transfers to bypass only in the event of internal failure, overload, or overheating, ensuring zero transfer time for connected loads.

A line interactive UPS supplies power through bypass via an internal transformer during normal operation. The transformer acts as a charger simultaneously. Upon mains failure, it converts battery DC power to AC output. It offers improved voltage regulation over off-line topology without the full cost of an on-line system.

Consider the following when selecting a UPS:

1. Understand the full specifications of each UPS topology.
2. Assess the power quality requirements of your environment.
3. Evaluate current load capacity and anticipated future growth.
4. Select reputable brands with established manufacturing credentials.
5. Match the UPS to your specific operational requirements.

Key evaluation criteria include:

1. UPS reliability and operational stability.
2. Technical expertise and product development capability of the supplier.
3. High efficiency and low acoustic noise levels.
4. Supplier reputation and financial standing.
5. International safety certifications such as TUV, UL, and CSA.
6. Manufacturing facility certifications such as ISO 9001.

Yes. Outages are only one form of power disturbance. High voltage, low voltage, and voltage spikes are more common and can cause significant equipment damage. A UPS provides comprehensive protection including voltage regulation, surge suppression, and sag protection—regardless of how frequently full blackouts occur.

The RJ11 connector is used to protect telephone lines. It allows connection of phone handsets, fax machines, modems, and ADSL equipment to provide surge and transient protection on the line side.

Common power quality issues include sags, spikes, surges, electrical noise, and transients. These can cause data corruption, equipment damage, or significantly shorten the operational lifespan of sensitive electronics.

Typical power supply disturbances include: blackouts, voltage sags, voltage surges, sustained undervoltage, sustained overvoltage, frequency fluctuations, conducted interference, switching transients, and harmonic distortion. Each can affect equipment performance and reliability in different ways.

A UPS can perform the following functions:

• Power failure protection
• Under-voltage and over-voltage protection
• Waveform distortion correction
• Frequency stabilisation
• Voltage regulation
• Normal-mode and common-mode noise rejection
• Surge and transient response protection
• Power supply monitoring

A UPS uses internal batteries to guarantee continuous power to connected equipment even when the mains supply fails. Key benefits include:

• Business operations continue uninterrupted during power failures.
• Users are not disadvantaged by sudden equipment shutdowns.
• Equipment is protected from the stress of uncontrolled power cycles.
• Data is preserved, preventing loss from ungraceful shutdowns.

Runtime depends on the UPS capacity, battery condition, and the power draw of connected equipment. A typical workstation setup may be sized for 10–15 minutes of runtime. Applications requiring extended autonomy—such as data centres or critical infrastructure—require a detailed load analysis and a purpose-built backup solution.

UPS capacity is expressed as a VA (volt-ampere) rating. This represents the maximum VA output the unit can deliver. Because computers and other non-resistive loads have a power factor below 1.0—commonly around 0.6 to 0.7—the actual watt draw must be divided by the power factor to determine the required VA rating. For example, a 100 W load at PF 0.6 requires a UPS rated at approximately 167 VA.

Key hardware specifications to review include:

• Operating topology (offline / line interactive / online)
• Input voltage range
• Input frequency range
• Input power factor
• Load power factor
• Overload capacity
• Transfer time
• Output voltage stability
• Output voltage distortion (THD)
• Crest ratio
• Unbalanced load capability
• Cold-start function
• Bypass function
• Generator compatibility
• Battery management level
• UPS efficiency (%)