Control apparatus for regulating an overspeed condition of an electric generator

Claim 1

CONTROL APPARATUS FOR REGULATING AN OVERSPEED CONDITION OF AN ELECTRIC GENERATOR DRIVEN BY A PRIME MOVER COMPRISING AN IMPEDANCE OF PREDETERMINED MAGNITUDE, MEANS FOR ELECTRICALLY CONNECTING SAID GENERATOR TO A LOAD, AN ELECTRIC CIRCUIT BREAKER INCLUDING AN ACTUATING COIL AND A PAIR OF CONTACTS, MEANS ELECTRICALLY CONNECTING THE CONTACTS OF SAID CIRCUIT BREAKER IN SERIES WITH SAID IMPEDANCE TO SAID GENERATOR, A FIRST SOURCE OF ELECTRIC CURRENT ELECTRICALLY CONNECTED IN SERIES WITH SAID COIL, A RELAY HAVING A PAIR OF CIRCUIT INTERRUPTING CONTACTS ELECTRICALLY CONNECTED IN SERIES WITH SAID COIL AND SAID FIRST SOURCE OF CURRENT, A TRANSFORMER HAVING ONE WINDING THEREOF DISPOSED IN INDUCTIVE RELATION WITH THE CURRENT SUPPLIED BY THE GENERATOR TO THE LOAD TO PROVIDE A SECOND SOURCE OF ELECTRIC CURRENT PROPORTIONAL TO GENERATOR OUTPUT, SAID TRANSFORMER BEING ELECTRICALLY CONNECTED TO ENERGIZE SAID RELAY THEREBY TO MAINTAIN THE RELAY CONTACTS OPEN WHEN THE LOAD EXCEEDS A PREDETERMINED VALUE AND TO EFFECT A CLOSING OF SAID CONTACTS WHEN THE LOAD CURRENT FALLS BELOW SAID PREDETERMINED VALUE, A TIME-LIMIT SWITCH HAVING A PAIR OF CIRCUIT-INTERRUPTING CONTACTS ELECTRICALLY CONNECTED IN SERIES WITH THE ACTUATING COIL OF SAID CIRCUIT BREAKER, SAID TIME-LIMIT SWITCH BEING EFFECTIVE TO OPEN ITS SERIES-CONNECTED CONTACTS AFTER A PREDETERMINED TIME INTERVAL, MEANS RESPONSIVE TO THE ENERGIZATION OF THE ACTUATING COIL OF SAID CIRCUIT BREAKER FOR INITIATING SAID TIME INTERVAL, A SECOND SWITCH ELECTRICALLY CONNECTED IN PARALLEL WITH THE CONTACTS OF SAID RELAY, SAID SECOND SWITCH BEING ADAPTED FOR OPERATION INDEPENDENT OF THE OPERATION OF SAID RELAY THEREBY TO AFFORD MEANS FOR TESTING THE OVER SPEED REGUALTING MEANS BY ENERGIZING THE ACTUATING COIL OF SAID CIRCUIT BREAKER TO CONNECT THE IMPEDANCE TO THE GENERATOR WITHOUT INTERRUPTING THE LOAD CURRENT OF SAID GENERATOR.