What is an online UPS?

What is an online UPS?

Offline UPS

The Offline UPS functions by directly providing the AC power to the device connected to the load. During normal operation, the AC power is supplied directly to the load, while the battery is charged with the help of the rectifier circuit.

However, in the event of a power outage, the Offline UPS switches the position of the transfer switch to connect the load to the battery backup path. The charged battery then supplies DC power to the inverter, which converts it into AC and supplies it to the load terminal.

Benefits of Offline UPS

• One significant advantage of the Offline UPS is its low design cost in comparison to the Online UPS.
• The internal control of the Offline UPS is simple, as there are only two paths, which work at different times according to the position of the transfer switch.
• The efficiency of the Offline UPS is high because the battery backup and inverter are not always ON, as they are in the case of the Online UPS.

Drawbacks of Offline UPS

• The electric signal obtained from the Offline UPS has poor quality because the inverter is not always ON.
• In case of power outage, the transfer time is approximately 5ms, during which there will be no output power. There will be a slight disruption in the output power due to transfer time.
• Since the Offline UPS directly supplies AC power when it is available, any spikes or surges present in the input voltage will also be transmitted to the output circuit.

Comparison of On-Line and Off-Line UPS

1. Performance Comparison

• Efficiency: On-Line UPS is generally more efficient than Off-Line UPS due to the continuous regulation of the power supply.

• Power protection: On-Line UPS provides a higher level of power protection than Off-Line UPS, making it suitable for critical equipment.

• Voltage regulation: On-Line UPS can regulate the output voltage, ensuring that the connected equipment receives stable power, while Off-Line UPS cannot regulate voltage.

• Switching time: On-Line UPS has a seamless transition between power sources, while Off-Line UPS has a delay in switching to battery power.

2. Cost Comparison

• Initial cost: On-Line UPS is generally more expensive than Off-Line UPS due to the higher level of power protection provided.

• Operating cost: On-Line UPS consumes more energy than Off-Line UPS, resulting in higher operating costs.

3. Application Comparison

• Suitable applications for On-Line UPS: On-Line UPS is suitable for critical equipment such as servers, medical equipment, and industrial machinery.

• Suitable applications for Off-Line UPS: Off-Line UPS is suitable for basic power backup needs such as desktop computers and small appliances.

Key Difference Between Online UPS and Offline UPS
 

The main differences between Online UPS and Offline UPS are in their operation. Online UPS supplies AC power through a rectifier and inverter circuit even when AC mains power is available, whereas Offline UPS directly supplies AC mains power to the load circuit when the power supply is available. Transfer time is a crucial factor that distinguishes the two types of UPS. Online UPS has zero transfer time as there is no switching between the inverter and mains supply path, while Offline UPS has a transfer time of approximately 5ms.

Another significant difference is that the inverter in Online UPS is always ON, while the inverter in Offline UPS is only active during power outages. Online UPS is generally more expensive than Offline UPS. However, the efficiency of Offline UPS is generally higher compared to Online UPS because the inverter and rectifier circuit are not constantly active in Offline UPS.

Conclusion

In conclusion, both Online UPS and Offline UPS are important for providing uninterrupted power supply. The choice between them depends on the specific application requirements. Offline UPS may be suitable for applications where a slight transfer time delay and cost-effectiveness are acceptable. On the other hand, Online UPS may be necessary for critical applications such as medical equipment, industries, and telecommunication, where even a slight transfer time delay is not desirable, despite the higher cost.

FAQ- about - online UPS

How UPS online works?

The online UPS takes the incoming AC power supply and converts it to DC using a a rectifier to feed the battery and the connected load via the inverter so that no power transfer switches are necessary.

Where online UPS is used?

Online UPS systems are typically more expensive than offline UPS systems, but they offer the highest level of protection and are often used in mission-critical applications such as data centers and hospitals.

What is a true online UPS?

True Online UPS (Uninterruptible Power Supply)

A True Online UPS provides the ultimate power protection with clean and stable electrical power for critical target loads. Using the Double Conversion topology the Online UPS isolates equipment from the commercial input power source.

Why online UPS is expensive?

Online UPS continuously converts power, while Offline UPS switches to battery mode during a power interruption. Why is Online UPS more expensive? Due to its continuous conversion mechanism and better protection features, Online UPS systems tend to be more costly.

Why online UPS is required?

An uninterruptible power supply's primary role is to provide short-term emergency power when there's a complete mains failure or blackout. In addition, most modern online UPS can correct a wide range of common power problems, including: Sags: short periods when the voltage is below the usual mains supply level.

Can online UPS work without a battery?

No, an online UPS (Uninterruptible Power Supply) cannot work without a battery.

How long do online UPS last?

eight to ten years

The general lifespan of a UPS electronics is eight to ten years, Batteries last for three to five years depending upon site condition. A UPS is rated by its VA or watt rating. The higher the watt rating, the longer the lifespan of your backup power supply will be.

What is the principle of UPS online?

An online UPS uses a "double conversion" method of accepting AC input, rectifying to DC for passing through the rechargeable battery then inverting back to 120 V/230 V AC for powering the protected equipment.

What is the difference between online inverter and UPS?

A UPS supplies consistent power and quality that is backed up by a battery, whereas an inverter changes DC power from a battery into AC power—it can provide short-term power while the main source of electricity is unavailable.

Is UPS 3 day expensive?

3 Day Select: $42.02 (1 to 3 business days for delivery) Next Day Air Early AM: $142.23 (1 business day for delivery) Ground: $18.59 (1 to 5 business days for delivery) Next Day Air Saver: $99.29 (1 business day for delivery)

Why do we use online UPS?

By using online UPS, you will get the highest level of power protection, conditioning, and backup. It ensures zero switchover time during mains outages. It provides completely regenerated output power.

Which battery is used in online UPS?

There are three main types of batteries used in uninterruptible power supplies: Nickel-Cadmium, Lead-Acid, and Lithium-Ion. There isn't a single “best” UPS battery technology – the choice should be made on a case-by-case basis.

Which type of UPS is better?

Offline UPS, also called standby UPS or battery backup, is a cost-effective choice. Better offline UPS systems switch to battery fast enough to prevent power anomalies and ride out short outages. An offline UPS protects against most spikes, but doesn't maintain perfect power during minor sags and surges.