SZ11 first S representation is a three-phase, if D is a single-phase; Z represents OLTC; 11/10/9 is the design number. . . S behind the F indicates that it is air-cooled cooling mode; S behind that S represents a water-cooled cooling method. . .

For three-phase connection, usually with Y, D, Z three kinds of connection. Which is commonly used in three Yy12, Yd11, Dy11 so on. Transformer connected group clock notation

Various inter-connected group of the primary-side voltage and the secondary voltage, some phase angle difference is 0 °, the phase angle difference is some multiple of 30 °. On the clock face, each between two adjacent digital angular difference of 30 °, so all kinds of connected group label, using the most appropriate clock

Transformer primary side of the wire voltage vector AB as long needle of the clock, it fixed point digital clock on 12, the secondary wire voltage vector ab as short hand of the clock. If the short needle also points to 12, then the vector AB and ab phase with the reading by the watch at 12 o'clock, this connection will be recorded as 12.

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