Which is one and half circuit breaker scheme?

One and Half Bus System & One And Half Circuit Breaker Scheme. One and half Bus System: In Switchyard two most Bus bar schemes are very popular one is One and Half Breaker Bus System (3/2 bus) and Double Bus Bar arrangement.

How many breakers are needed in a one and half bus?

In this bus configuration, three breakers are required for every two circuits – hence the “one and half” name. Think of it as, to control one circuit requires one full and a half breaker. The middle breaker is shared by both circuits, similar to a ring bus scheme where each circuit is fed from both sides.

How is one and half bus scheme similar to ring bus scheme?

Hence it is called one and half scheme. It is something like, for controlling one circuit we require one full and a half breakers. The middle breaker is shared by both the circuits. Like the ring bus scheme here also each circuit is fed from both the buses.

How are one half breakers used in substations?

The one-half breaker configuration is a v ariation of the ring bus concept on a multiple substation basis. As with the ring bus, two breakers must be tripped to isolate a faulted line or transformer. In the case of the one-half breaker configuration, one of the breakers is usually at the other end of the transmission line.

What kind of Breaker is used in an outside switchyard?

The 1½-breaker configuration is used mainly in countries outside Europe. It is employed for all voltages above 110 kV, but predominantly in the very high voltage range. The double busbars of these stations are arranged above, both outside or inside, and can be of tube or wire.

What kind of switchyards are used in Germany?

Diagonal layout with bypass bus, single-row arrangement The 420 kV switchyards of the German transmission grid are of the diagonal type. To meet the stringent demands of station operation and reliability, double or triple busbars with sectionalizing and an additional bypass bus are customary. Tube-type busbars are preferred.