| 摘要 |
Each contact of the auxiliary switchgear is in series with an electronic switch which closes the parallel path after closure of the auxiliary contacts. When the main contacts have closed the electronic switch and thereafter the auxiliary contacts are opened. The switching sequence is controlled in response to ON and OFF buttons 10 and 11 through memory 15 by selection circuits 16 for the auxiliary switchgear, 17 for the electronic switch, and 18 for the main switchgear. A test circuit 19 has inputs from sensors 20, 7, 21, 22, 23 monitoring respectively current flow in the main switchgear solenoid, position of the main contacts, state of the electronic switch, current flow in the auxiliary switchgear solenoid and position of the auxiliary contacts. Resettable tuners 25, 26, 27 delay operation of 16, 17 and 18 to allow time for tested conditions to settle down but if a fault is detected on test this is shown by warning circuit 24. <IMAGE> |
