High energy spring drive

A method for operating a drive unit to electrically close or open a circuit breaker, wherein the drive unit comprises a closing assembly positioned at a first end of the drive unit, an opening assembly positioned at a second end of the drive unit substantially parallel to the closing assembly, a charging assembly positioned between the closing assembly and the opening assembly, and a transmission assembly coupled to the charging assembly, the method comprising:

• receiving a trigger from a limit switch to energize the closing assembly and in response to receiving the trigger:
• supplying input power to the closing assembly through a worm wheel arrangement coupled to a motor to transfer torque to a motor shaft to energize the closing assembly;
• decoupling the charging assembly through a decoupling mechanism from the closing assembly to prevent transfer of torque from the closing assembly to the worm wheel arrangement on de-energization of the closing assembly;
• and
• latching a closing latch lever to a closing latch unit of the charging assembly to lock the closing assembly in an energized state;
• receiving a closing signal to electrically close the circuit breaker and in response to receiving the closing signal:
• releasing the closing latch lever to rotate the motor shaft to de-energize the closing assembly;
• rotating a cam of a cam-follower mechanism mounted on the motor shaft to cause a follower of the cam-follower mechanism mounted on an output shaft to rotate in a first direction during de-energization of the closing assembly;
• transmitting energy from the closing assembly to the transmission assembly coupled to the follower when the follower rotates in the first direction to electrically close the circuit breaker;
• transmitting energy through the follower to the output shaft coupled to the opening assembly to energize the opening assembly;
• and
• latching an opening latch lever mounted on the output shaft to an opening latch unit of the charging assembly to lock the opening assembly in an energized state;
• receiving an opening signal to electrically open the circuit breaker and in response to receiving the opening signal:
• releasing the opening latch lever to cause the output shaft to cause the follower of the cam-follower mechanism to rotate in a second direction during de-energization of the opening assembly;
• and
• transmitting energy from the opening assembly to the transmission assembly coupled to the follower of the cam-follower mechanism when the follower rotates in the second direction to electrically open the circuit breaker.