Answer Posted / devidas
First symbol/symbols, capital letters: HV winding connection.
Second symbol/symbols, small letters: LV winding connection.
Third symbol, number: Phase displacement expressed as the
clock hour number.
Winding connection designations
High Voltage Always capital letters
Delta - D
Star - S
Interconnected star - Z
Neutral brought out - N
Low voltage Always small letters
Delta - d
Star - s
Interconnected star - z
Neutral brought out - n
Phase displacement
Phase rotation is always anti-clockwise. (international
adopted convention)
Use the hour indicator as the indicating phase displacement
angle. Because there are 12 hours on a clock, and a circle
consists out of 360°, each hour represents 30°.
Thus 1 = 30°, 2 = 60°, 3 = 90°, 6 = 180° and 12 = 0° or 360°.
The minute hand is set on 12 o'clock and replaces the line
to neutral voltage (sometimes imaginary) of the HV winding.
This position is always the reference point.
Because rotation is anti-clockwise, 1 = 30° lagging (LV lags
HV with 30°)and 11 = 330° lagging or 30° leading (LV leads
HV with 30°)
To summarise:
Dyn11
Delta connected HV winding, star connected LV winding with
neutral brought out, LV is leading HV with 30°
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