What is the Difference Between Online and Offline UPS?

The main difference between online and offline UPS systems lies in their working principles, which affect their features, functionalities, benefits, and limitations. Here are the key differences between the two types of UPS systems:

1. Input: Online UPS systems receive a direct AC power supply and use an AC-DC inverter to power the electronic device. Offline UPS systems receive AC power and get charged, but the charged AC-DC inverter power is utilized only when there is a power failure.
2. Operating Temperature: Online UPS systems are connected to the main load at all times or until the battery gets charged. In this case, electronic devices receive power from the online UPS, not directly from the AC main supply. Offline UPS systems work better if they can switch in less time.
3. Cost: Online UPS systems generally cost more due to their more complex setup, while offline UPS systems are less expensive and require fewer parts.
4. Battery Usage: Online UPS systems use their batteries throughout the time they are connected to the main load, while offline UPS systems only use their batteries when there is a power failure.
5. Transfer Time: Offline UPS systems have a break in power to the load of typically 2 to 10 milliseconds when transferring between the inverter and the bypass. Online UPS systems, on the other hand, are silent and the load is unaware of the transfer between the mains and the inverter.

In summary, online UPS systems provide better protection and a more continuous power supply, while offline UPS systems are more affordable and suitable for applications with lower power requirements. Offline UPS systems are commonly used for households, small offices, and fields with relatively low requirements for power supply quality.

Comparative Table: Online vs Offline UPS

The main difference between online and offline UPS systems lies in the way they provide power. Here is a table comparing the two types of UPS systems:

Online UPS systems provide constant power to your equipment, even during a power outage, while offline UPS systems are less expensive but have a transfer time of approximately 5ms.