electrialstandards

Synchronization of Machines using dark lamp method:- If phase sequence of running machine is RYB and incoming machine who is to be synchronized with the system is abc, than synchronization switch would be put across contacts a-R, b-Y, c-B respectively. Simultaneous closure of these switches causes synchronization of incoming machine with the running machine. In dark lamp method of synchronization , There identical lamp’s L1, L2, L3 are contacted across a-R, b-Y, c-B respectively.  Voltage rating of these lamps should be twice the rated line to neutral voltage of the machine. Correct phase sequence can be verified if all the three lamps become dark together and bright together with same intensity of brightness. If same doesn’t happens than by changing any 2 terminals of incoming machine correct  phase sequence can be achieved. Image below shows how to Synchronize machines using dark lamp method:- If lamps never attain a dark phase but intensity of brightness of lamps changes with time