Title :
A new interruption method for low-voltage, high-capacity, air-break contactors suppressing the blowoff of a hot gas
Author :
Mori, T. ; Wada, Y. ; Hayashi, T. ; Kakizoe, M. ; Matsumoto, F. ; Masuda, S.
Author_Institution :
Mitsubishi Electric Corp., Hyogo, Japan
fDate :
Sept. 28 1991-Oct. 4 1991
Abstract :
A method was derived to suppress the blowoff of a hot gas from an arc chamber and to shorten arcing time in the interruption of overcurrents. The blowoff of the hot gas is suppressed by cooling with a porous metal plate attached in front of gas-exhausting holes of an arc chamber. From heat analysis, it is estimated that the temperature of the hot gas passing through the porous metal plate is lowered by about 95%. Arcing time is shortened by a unique commutation electrode and arc runner. In the interruption of a current of 6 kA at a 480 V circuit, the maximum arcing time is shortened by about 40%. From observation by a high-speed framing camera, it is concluded that the shortening of arcing time is due to an effective arc-drive by the commutation electrode and arc runner. This method has been applied to contactors of 600 A and 800 A frames having the maximum-rated operational voltage of 660 V.<>
Keywords :
circuit-breaking arcs; contactors; overcurrent protection; switchgear; switchgear testing; 480 V; 6 kA; 600 A; 660 V; 800 A; LV; air-break contactors; arc runner; arcing time; blowoff; commutation electrode; overcurrents; protection; switchgear; testing; Cameras; Circuit faults; Commutation; Contactors; Cooling; Electrodes; Laboratories; Magnetic materials; Temperature; Voltage;
Conference_Titel :
Industry Applications Society Annual Meeting, 1991., Conference Record of the 1991 IEEE
Conference_Location :
Dearborn, MI, USA
Print_ISBN :
0-7803-0453-5
DOI :
10.1109/IAS.1991.178089
