Mitsubishi Electric has been involved in SF6 circuit breaker developments from time of original discovery and US patents proving that SF6 gas possesses exceptional arc interrupting properties that would later lead to a world wide change to SF6 gas circuit breakers away from other types of circuit breaker medium. This pioneering involvement and SF6 experience comes by way of licensee and close partnership arrangements with Westinghouse Electric Corp. since the 1950’s. The partnership with Westinghouse extended to a 1985 US joint venture with Mitsubishi Electric forming WM POWER PRODUCTS INC. (WMPPI). In March of 1989, the WMPPI joint venture evolved into becoming a wholly owned subsidiary of Mitsubishi Electric Corp. and today is known as Mitsubishi Electric Power Products Inc. (MEPPI).

MEPPI essentially has a world wide scope with numerous operating divisions producing electrical products including Power Circuit Breakers. Our power circuit breakers cover a full range of voltages from 15 kV class to 550 kV and developments are underway at 800 kV. These breakers also have interrupting ratings from 25 kA to 63 kA

For the 15 kV class MEPPI provides modern day vacuum breakers and SF6 Gas breakers at 72.5 kV and above. The product offering is complemented with a line of special controlled phase closing and controlled phase opening breakers of various ratings. These are often referred to as synchronous close breakers.

All breakers offered by MEPPI are thoroughly tested in the state of the art facilities including High Voltage Lab., High Power Lab., Environmental Test Lab., Seismic Test Lab., etc that are located at the Mitsubishi Electric ITAMI works in Japan. Complete factory production tests are also performed on each breaker at the MEPPI production facility at Warrendale PA. A summation of all the testing that goes into the circuit breaker product provides both MEPPI and the customer assurance that the equipment will perform reliably in the field.

Specific breaker types and ratings are covered in the following segments.

Mitsubishi Electric, a pioneer of SF6 circuit breaker development, manufactures electrical products including power circuit breakers covering a range of voltages from 15kV to 550kV with developments underway at 800kV. Mitsubishi Electric’s breakers also have interrupting ratings from 25kA to 63kA,

For the 15kV class, we offer vacuum breakers and SF6Gas breakers at 72.5kV and above. Mitsubishi Electric’s electrical product offering is complemented with a line of special controlled phase closing and controlled phase opening breakers of various ratings (often referred to as synchronous close breakers).

Complete factory production tests are performed on each breaker Mitsubishi Electric’s production facility in Warrendale, Pa. A summation of the testing that goes into the circuit breaker product assures both MEPPI and the customer that the equipment will perform reliably in the field.