Transformer Open Delta Connection
Open Delta Connection Definition
An open delta connection transformer uses two single-phase transformers to create a three-phase supply, typically used in emergencies.
Efficiency
Open delta systems are less efficient than closed delta systems because they provide less power output while operating at full transformer capacity.
Calculation Formula
The capacity of an open delta system is found by multiplying the square root of three with the rating of one transformer, resulting in a lower total power output compared to a closed delta system.
Capacity of open delta system = 0.577 x rating of closed delta system=0.577 x 30 kVA= 17.32 kVA
Diagram
The connection diagram shows how two transformers supply a three-phase load with a unity power factor, illustrating the system’s operation.
Load Distribution
In an open delta system, each transformer supplies 10 kVA, totaling 17.32 kVA, demonstrating how power is distributed and why efficiency drops.
