InterlockingHEI-JPCL-1216_TS-0562_LV_SLDs_MOM 20/07/20Interlocking between the LV incomer and upstream MV feeder CB is not apparent and shall be included in consideration of the following:(i)Earth switch of up steam breaker should be interlocked with Test or Rack out position of LV breaker. (ii)Service Position of LV breaker not permitted to close HV upstream Earth switch. (iii)While closing HV feeder earth switch, It has to ensure LV breaker is not in service position.