Disconnection times on a system if a stand by generator is used

On a fully designed power distribution system, clearly the fault levels, earth loop impedances and ultimately fuse disconnection times are determined by the system parameters Transformer %Z etc one or two in parallel for min and max fault levels levels. What needs to be considered when bringing on a stand-by generator, clearly all Fault levels, Earth loop impedances and consequently fuse disconnection times would change because of the Generator parameters. How would you design in these new parameters, bearing in mind that disconnection times on a large system may no longer be achievable 

Parents
  • It was mentioned earlier, but UPSs have a similar issue for me, re. Disconnection times and I feel from what I have seen in practice these issues are ignored, if a fault occurs when the UPS is being utilised, (I know the likelihood is extremely low) because the disconnection times are not met, the UPS can shut down totally. And the UPS reason fo existing I.e. maintaining essential supplies is thwarted 

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  • It was mentioned earlier, but UPSs have a similar issue for me, re. Disconnection times and I feel from what I have seen in practice these issues are ignored, if a fault occurs when the UPS is being utilised, (I know the likelihood is extremely low) because the disconnection times are not met, the UPS can shut down totally. And the UPS reason fo existing I.e. maintaining essential supplies is thwarted 

Children
  • And the UPS reason fo existing I.e. maintaining essential supplies is thwarted 

    Many UPS are provided for business continuity, rather than for reasons of safety.

    When we are talking about safety services, other things (like higher integrity wiring systems etc.) come into play, and a basic UPS may not cut the mustard (for example certain UPS could be used to provide a CPS but they have to meet all of the requirements of BS EN 50171 and not simply BS EN 62040 series.