The Offline UPS directly supply the AC power to the device connected to the load. In case of power failure, the offline UPS changes the position of the transfer switch. And it connects the load to the battery backup path.
The battery of the offline Ups gets charged during the availability of AC power. In that condition, the AC power is directly supplied to the load circuit, and at the same time the battery of the offline ups gets charged with the help of rectifier circuit
Advantages of Offline UPS
- The cost of designing of Offline UPS is very low in comparison to the online UPS.
- The internal control of offline ups is simple as two paths are there and both works at the different time according to the position of the transfer switch.
- The efficiency of the offline UPS is high because of the battery backup and inverter in not ON all the time as in case of Online UPS.
Disadvantages of Offline UPS
- The quality of the electric signal obtained from Offline UPS is very poor because the inverter is not always ON.
- The transfer time in case of the power outage is about 5ms, during this time there will be no output power. There will be a slight disruption in the output power due to transfer time.
- The offline Ups directly supply the AC power when it is available, then the spikes and surges if present in the input voltage will also be passed to the output circuit.