Sprinkler (Fire) Pumps - Generator Secondary Supply

Good afternoon.


I am currently working on the design of a 5 storey commercial building equipped with a sprinkler system.


The sprinkler pumps will naturally be provided with a secondary supply, which in our case will be via a diesel generator.


While sizing the generator, i was advised by the pump manufacturers that the generator needs to be sized based upon the Locked Rotor Current + Starting Current of the

sprinkler pump as per BS 12845 and LPC Rules for automatic sprinkler installations TB210.


I checked BS 12845 (2015+ A1:2019) and TB210 (2009 - don't have the 2015 edition), but couldn't find anything clearly confirming the above.


I have also seen references to NFPA 20 and specifically 695.3 which states that generators should be selected with sufficient capacity (kW) to permit the normal starting and running of the motors in the fire pump system -- plus all other connected loads.


Does anybody have any relevant experience on the matter? Do i really have to provide a generator for the LRC + SC? Any ways around it? 


I would appreciate your thoughts.


Thank you in advance for your help.


Ilias