Safety circuit

Claim 1

SAFETY CIRCUIT FOR A SYSTEM THAT INCLUDES A PUMP AND A MOTOR TO DRIVE THE PUMP, COMPRISING A SEQUENCING SWITCH CONNECTED TO THE MOTOR FOR CONTROLLING THE FLOW OF POWER THERETO, A RELAY FOR ACTUATING THE SEQUENCING SWITCH, A MAINTAINING SWITCH CONNECTED IN SERIES WITH THE SEQUENCING SWITCH RELAY AND BEING ARRANGED TO OPEN AND CLOSE SIMULTANEOUSLY WITH THE SEQUENCING SWITCH IN RESPONSE TO SAID RELAY, A NORMALLY OPEN STARTING CIRCUIT CONNECTED IN PARALLEL WITH THE MAINTAINING SWITCH TO THE SEQUENCING SWITCH RELAY AND HAVING A MANUALLY OPERABLE SWITCH FOR CLOSING THE STARTING CIRCUIT TO ENERGIZED THE SEQUENCING SWITCH RELAY FOR STARTING THE MOTOR, A TEMPORARY RUNNING CIRCUIT CONNECTED TO AND CLOSED BY THE MAINTAINING SWITCH WHEN THE MOTOR IS STARTED AND HAVING A TIME DELAY RELAY SWITCH MEANS RESPONSIVE TO POWER FLOW TO THE MOTOR FOR OPENING SAID TEMPORARY RUNNING CIRCUIT AFTER A PREDETERMINED TIME INTERVAL AFTER THE MOTOR IS STARTED, AND AN OPERATING CIRCUIT CONNECTED IN PARALLEL WITH THE TEMPORARY RUNNING CIRCUIT TO THE MAINTAINING SWITCH AND HAVING A SENSING SWITCH ASSOCIATED WITH THE PUMP THAT OPENS AND CLOSES AT A FREQUENCY RELATIVE TO THE SPEED OF THE PUMP AND A TIME DELAY RELAY SWITCH MEANS RESPONSIVE TO THE SENSING SWITCH THAT OPENS WHEN THE PUMP FAILS TO RUN AT A REQUIRED SPEED TO DEENERGIZE THE SEQUENCING SWITCH RELAY TO STOP THE PUMP.