This DIN96 unit is a three lamp synchroscope arranged to give lamp dim indication at the “in phase” condition. When the phase of busbar and incoming voltages are in coincidence, the lamp located at 12 o’clock position will be out, and the remaining two lamps will be lit.
Direction of lamp “rotation” pattern indicates if incoming generator is TOO SLOW (-) or TOO FAST (+) relative to busbar supply.
The unit is rated for continuous operation and may be left permanently connected to the two supplies after synchronisation.
It must be connected to the two supplies in strict accordance with the phase sequence (L1,L2,L3) shown.