UPS Manual Bypass Switch

The load will continue to operate until the moment the power fails.

thats is ok but if we are changing the moment Bypass is a different and inv is also a different phase so while we change the switch is there any spark has come

Not if the equipment has been correctly designed, installed and commissioned.

What does it say in the UPS's manual?

What does it say in the UPS's commissioning records?

we have to change the control or static switch into bypass mode forst then we have to change the Manual Bypass switch normal into bypass position

this is the manual procedure

If all else fails, read the instructions. it works most times and if it doesn't then you can blame the manufacturer.
Why did you ask the question in the first place, when you have the answer?

Quite. If the OP's installation is correct then there will be no consequence in operating the bypass switch until the power fails.

no problem to change to manual bupass if u r on any mode as it is the function of the switch . even if u turned off the ups no problem as the load will be fed already from the main supply bypass. but if failure happen in the main supply your load will not be fed

During the change over, for maintaning the continuity of the service, the bypass switch is made as a 'make before break' switch (also called close transition switch). This switch is generally operated manually and it should be operated only when the UPS supply and the bypass supply are in sync, otherwise the system may damage with having short circuiting between the UPS and the bypass source. The UPS should have a signal light which shows both of the supplies are in sync or not. For the safety reason, generally there is a warning label installed near the bypass switch indicating not to operate this switch if the sources are out of sync.

Also see this thread:

http://cr4.globalspec.com/thread/58641/ATS-for-a-PDP-to-Power-Equipments

- MS