In this method of interconnection, the dissimilar ends of three phase windings are joined together i.e. finishing end of one phase is connected to the starting end of the other phase and so on to obtain a closed circuit.
The three line conductors are taken from the three junctions of mesh and are denoted by R, Y and B. This is called three phase three wire delta connection.
In the balanced delta connection the three phase voltages are equal in magnitude and displaced 120o from one another and their phasor sum is zero.
In the delta connection, no neutral exists and, therefore, only three phase, three wire systems can be formed. The delta connection is also known as mesh connection.
In a Balanced Delta Connection
VL = Vph (in magnitude and phase)
IL = √3 Iph (in magnitude)
In a balanced delta connection line current lags the phase current by 30o.
Power 3- φ = √3VLIL cos φ
Power 3- φ = 3VphIph cos φ
Applications of Delta Connections
- The delta connection is only connection suitable for rotary converters.
- Transformers work better with delta connection.
- Delta connection is mostly used for low voltage three phase motors.
Balanced Delta Connection
A balanced delta connection is one in which the three phase voltages are equal in magnitude but displaced 120o from one another. In a balanced delta connected system, three line voltages will also be equal in magnitude but displaced 120o from one another.