What is the difference between online ups and offline ups?

Answer Posted / shiva shankar

The offline UPS is in standby mode. The charger is maintaining the battery, but the inverter stage is not running. Power goes from input to output, bypassing the inverter.
In this configuration, the charger and inverter design is less, as the charger is usually in trickle mode and the inverter does not need to run continuously. On power fail, the inverter starts up and takes the load. There is a glitch in output, a few line cycles, but most loads can handle this.
The online UPS runs all the time. The charger now runs the inverter, as well as maintaining charge on the battery. The inverter supplies the load. Power goes from input to charger to inverter to output.
In this configuration, the charger and inverter design is more, as they need to run continuously. On power fail, there is no glitch, because the inverter is already running and supplying the load. Usually, there is synchronization between the inverter and the line, so that failure of the inverter can initiate fall-back to the line without glitch.


Read more: http://wiki.answers.com/Q/What_is_the_Difference_between_off-line_and_online_UPS#ixzz1MJtsQvtb

Is This Answer Correct ?    2 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

DESCRIBE THE CONSTRUCTION ANDOPERATION OF BELT CONVEYORS AND SCR CONVEYORS , DRAW NEAT SKETCHES

1707


what is meant by tranformer impedance?

2253


what will happen if frequency is below 50 hz?

1674


Draw torque - speed curve and load curve of induction motor? mark operating point ?

1668


What are the applications of the electric motors?

691






could you measure current in parallel?

771


What is the mechanism of WTI

1447


why steady state stability limit is greater than transient stability limit ? How it can be explained ?

2526


How to calculate the no of Ceiling fan (1200mm sweep) per unit area?

1505


what is class of SPD and dittels of all class ?

1668


Define ampere

840


Brief working principle of stabilizer,application & safety precautions

5260


Give some example of fault limiting devices?

906


any application of back emf

1751


how circuit breaker work.. what is the operations taking place inside a circuit breaker when an overcurrent occurs... is it similar to fuse?

1715