| 摘要 |
PURPOSE:To cut out a circuit during the short-circuit of an inverter by providing the first no-fuse breaker at the primary side of a transformer, providing a no-fuse breaker at the secondary side, and giving the trip characteristics to the no-fuse breaker at the secondary side, which are different from those at the primary side. CONSTITUTION:An ordinary no-fuse breaker has heat limit characteristics and the trip characteristics of about 0.5 to 1 seconds after a flow of 800% of a rated current. Because of this, a contactor 10 is cut out before the trip operation of a no-fuse breaker, and a large current is cut out by the contactor. For this purpose, the contactor must have a very large capacity; this is so expensive and thus not economical. Therefore, by using an instantaneous operating type at the secondary side having the trip characteristics different from those of the primary side of a transformer, NIB2 will trip instantly even if the short- circuit current is about 800% during the short-circuit of an inverter, so that cutout duty will not occur to the contactor. |
