Difference between Online UPS and Offline UPS
Online UPS and offline UPS are two important types of UPS. Both provide power to the device in the event of a power failure. But the similarities end there. The main difference between both UPS is that an online UPS uses a combination of a rectifier and inverter to provide power. It powers both the load and the battery at the same time so that the battery can be recharged to provide power in the event of a power outage.
In contrast, an offline UPS delivers AC power directly to the load by turning on the transfer switch. Also, in the event of a power outage, offline UPS provides power from battery backup. Another important difference between both UPS is the requirement for large heat sinks.
An online UPS consists of a rectifier that directly powers both the inverter and the battery. Therefore, heat dissipation is greater. Therefore, an online UPS requires a larger heatsink than an offline UPS.
There are some other huge differences between the two UPS. Kondaas Team has explained this using the comparison table below.
Comparison between Online / Offline UPS
|ONLINE UPS||OFFLINE UPS|
|An online UPS is one that supplies the AC power through a rectifier and inverter combination circuit in case of power availability as well as in power outage.||An offline UPS is one that supplies the AC mains power directly to the load in case of power availability and whenever there is power outage it supplies power to load through the backup battery.|
|Heat dissipation and Operating temperature|
|Heat dissipation is more in comparison to offline ups because online ups is ON continuously.||Heat dissipation is low because offline ups are switched ON only in case of a power outage.|
|Time required to switch the path during a power outage is termed transfer time. As the transfer switch in case of online ups is always ON thus, transfer time is zero.||Transfer time is about 5 milliseconds|
|Online UPS is immune to external distortions such as surges, spikes and power failure.||Offline UPS is not immune to external distortion.|
|It requires more components and thus it is complex to design.||It requires fewer components and is thus simpler in design.|
|Large heat sink is required in case of online ups.||A small heat sink is required in case of offline ups.|
|Expensive in comparison to offline ups.||Less expensive than online ups.|
|On-time of Inverter|
|The inverter is ON during power outages as well as during power availability.||The inverter is ON only when the power failure occurs.|
|In medical equipment, telecommunication equipment, etc.||In computers, PCs, etc.|
Key Differences Between Online UPS and Offline UPS
The main difference between the two UPS is how they work. An online UPS supplies AC power through a rectifier and inverter circuit, even if AC power is available from the mains. In contrast, an offline UPS supplies AC utility voltage directly to the load circuit when utility power is available.
Transfer time is the key term that distinguishes online UPS from offline UPS. Online UPS switchover time is zero because there is no switchover between the inverter rectifier path and the utility path. On the other hand, the offline UPS transmission time is about 5ms.
Another important difference between both UPS is that in an online UPS the inverter is always on, whereas in an offline UPS the inverter is only on when utility power is unavailable.
Online UPS costs more than offline UPS.
The efficiency of an offline UPS is higher than that of an online UPS because the inverter and rectifier circuits of an offline UPS are not always on.
A UPS is a device that provides uninterrupted power to load circuits, even in the event of a power failure. An online UPS is a UPS that supplies AC power to the load circuit through a rectifier and inverter circuit while simultaneously supplying power to the backup battery.
An offline UPS supplies AC power directly to the load circuit and is connected to the inverter, rectifier, and battery backup only in case of power failure.
Both are important devices for obtaining an uninterruptible power supply. Which UPS to use depends on your application.
An offline upgrade is your best bet if you can tolerate a few milliseconds of transmission time and are looking for a cheaper upgrade.
However, suppose you are dealing with applications where transmission times of a few milliseconds are not desirable, such as medical equipment, industry, or telecommunications. In that case, you should consider using an online UPS, but at a higher cost.
Online UPS or Offline UPS, Kondaas has a solution and a product for all! You may visit the UPS Product section for more details.