Non specific to BK, but break in fires usually refer to temps more than a setting.  Each MFG and manual could have their own specifics, but in general a 3 fire break in does about anything you would need to do.  First fire - low temps (say 200-250F ish).  Let cool.  Second fire - mid temps (somewhere in the world of 400F).  Third and final - let it rock and roll while making sure to not overfire.
ETA - any specifics from the manual trump the above info.
	
		
			
		
		
	
				
			ETA - any specifics from the manual trump the above info.
	
	