Intelligent MV and HV circuit breaker testing and diagnosing unit

A smart circuit breaker tester for use with power station/plant feeders to evaluate vacuum circuit breaker/air circuit breaker (VCB/ACB) contacts, comprising:

• a programmable logic controller having at least one plug and play connector adapted for connection to a circuit breaker under test, the programmable logic controller having input circuits including a current transducer and a resistance measuring circuit disposed between the plug and play connector and the programmable logic controller for receiving response signals from the circuit breaker under test and output circuits including relay means for sending signals to the circuit breaker under test initiating circuit breaker testing including an opening time and testing an opening drain current, a closing time and testing a closing drain current, and measuring a contact resistance and a spring charging current;
• human-machine interface means operatively connected to the programmable logic controller, the human-machine interface means having a display and a data input adapted for receiving data and commands from a user for input to the programmable logic controller,
• wherein the opening time is defined as a time interval between when a smart circuit breaker open command is activated to when a circuit breaker status feedback input is deactivated,
• wherein in response to said open command being activated, a first relay function is energized, contacts of a positive terminal of a power supply and contacts of a negative terminal of said power supply are both closed which allows said opening drain current to pass through said circuit breaker opening coil via a secondary contact block and a current transducer, and a spring is released to return the contacts back to a desired position,
• wherein said current transducer measures the circuit breaker opening drain current required during an opening operation and provides a 4-20 mA output to the programmable logic controller,
• wherein the opening drain current is defined as a current drawn by a circuit breaker opening coil or drained through the second contact block from a circuit breaker tester power supply unit when an open command is activated,
• wherein the closing time is defined as a time interval between a smart circuit breaker close command is activated to when the circuit breaker status feedback input is activated,
• wherein the closing drain current is defined as a current drawn by a circuit breaker closing coil or drained through the secondary contact block from the circuit breaker tester power supply unit when a closing command is activated,
• wherein in response to said closing command being activated, a second relay function is energized, contacts of a positive terminal of a power supply and contacts of a negative terminal of said power supply are both closed which allows said closing drain current to pass through said circuit breaker closing coil via a secondary contact block and a current transducer, and a spring is released to close the circuit breaker,
• wherein said current transducer measures the circuit breaker closing current required during a closing operation and provides a 4-20 mA output to the programmable logic controller,
• wherein the contact resistance is defined as a resistance to a current flow when vacuum circuit breaker or air circuit breaker contacts touch one another in a closed condition of the smart circuit breaker tester,
• and wherein the spring charging current is defined as a current drawn by a spring motor in the circuit breaker to charge springs.