Exam 29: Three-Phase Transformers

A wye-delta transformer has a secondary phase voltage of 480 V. A delta-connected resistive load has a resistance of 12 Ω in each leg. What is the current in each load leg?

In three-phase transformer connections, the primary leads are labeled with the letter and the secondary leads are labeled with the letter .

The main power distribution system of a large industrial plant is generally shown using a(n) diagram.

A wye-delta transformer has a turns ratio of 2:1. It has a secondary line voltage of 480 V. The secondary is connected to a wye-connected three-phase resistive load of 50 Ω in each phase. What is the primary phase current?

A delta-delta transformer has a primary voltage of 7200 V and a secondary voltage of 360 V. What is the turns ratio?

A wye-delta transformer has its connected as a wye and its connected as a delta.

In an open delta with a center-tapped transformer, label the two ends of the center-tapped transformer as L2 and L3 and label the high leg as L1. The current flow in the neutral (center tap) is equal to .

When using an open delta with a center tapped transformer, one wire is the high leg. The high leg is the one that _____.

An open delta transformer is assembled from two 150 kVA transformers. The output power of the open delta is _____.

When single-phase loads are tied to a three-phase transformer, the phase currents of the transformer will be automatically balanced.

A wye-delta transformer has a turns ratio of 2:1. It has a secondary line voltage of 480 V. The secondary is connected to a wye-connected three-phase resistive load of 50 Ω in each phase. What is the current flow is in each load resistor?

In an open delta with single-phase loads, the high leg must be identified by .

A wye-delta transformer has a turns ratio of 2:1. It has a secondary line voltage of 480 V. The secondary is connected to a wye-connected three-phase resistive load of 50 Ω in each phase. What is the secondary phase current?

A delta-wye transformer has its connected as a delta and its connected as a wye.

An open delta connection is made using single-phase transformers.

A wye-delta transformer has a primary voltage of 7200 V and a secondary voltage of 360 V. What is the turns ratio?

What function is performed by dielectric oil?

An open delta transformer is assembled from two 50 kVA transformers. The output power of the open delta is _____.

A wye-connected secondary has a phase voltage of 277.14 V. What is the line voltage?

A delta-wye transformer has a turns ratio of 9:1. The primary line voltage is 3600 V. What is the secondary line voltage?