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
  • Well that level sets the upper level fault handling of your design, and may need death or glory fuses near the origin, or surprisingly large front end MCCBS etc. But, you also have a second limit - with the rather uncertain and load dependent source impedance of genset it must also operate ADS properly,  Usually you cannot do both of these  on MCCB and MCB alone. Enter the earth fault trips, as above ;-)
    Mike.

Reply
  • Well that level sets the upper level fault handling of your design, and may need death or glory fuses near the origin, or surprisingly large front end MCCBS etc. But, you also have a second limit - with the rather uncertain and load dependent source impedance of genset it must also operate ADS properly,  Usually you cannot do both of these  on MCCB and MCB alone. Enter the earth fault trips, as above ;-)
    Mike.

Children
No Data