WD Partners Electrical Design Engineer Interview Questions and Answers

Fault current for primary and secondary side of transformer can be calculated using Ohm's law and transformer impedance.

• Determine the transformer impedance

• Calculate the voltage drop across the impedance

• Use Ohm's law to calculate the fault current

• For primary side, use the voltage rating of the transformer

• For secondary side, use the voltage rating of the load

• Consider the type of fault (3-phase, single-phase, ground fault...read more

NEC codes dictate wire sizing, load calculation, breaker sizing, and disconnect sizing for electrical design.

• NEC 310-16 provides guidelines for wire sizing based on ampacity and temperature rating

• NEC 220 provides guidelines for load calculation based on the type of building and its intended use

• NEC 240 provides guidelines for breaker sizing based on the wire size and load calculation

• NEC 430 provides guidelines for disco...read more