Transformers.

DOE-STD-1170-2003

Describe the function and importance of the following control and protective

devices:

Circuit breakers

Protective relays

Fuses

Transient protection

Compare and contrast the characteristics of three-phase and single-phase

distribution systems.

Discuss the principles associated with ensuring continual power availability during

electrical outages.

Explain the following terms as they relate to power systems:

Fault current

Available fault current

Fault duty

Discuss the safety considerations associated with high voltage transmission

systems.

Explain the requirements for and uses of alternate power supplies.

Discuss the uses of different voltages in a facility.

Discuss the reasons for using single phase versus 3-phase power systems in a

facility.

10.

Electrical systems personnel shall demonstrate a working level knowledge of

transformers.

Supporting Knowledge and/or Skills

Define the following terms as they apply to transformers:

Turns ratio

Efficiency

Describe the differences between a wye-connected and delta-connected

transformer.

Using the type of connection and turns ratios for the primary and secondary of a

transformer, calculate voltage, current, and power for each of the following types:

Delta - Delta

Delta - Wye

Wye - Delta

Wye - Wye