Master preparation: integrated technical judgment and review

Bring together technical review and judgment for Master preparation.

What you’ll do

Your attempt
Try a changed case
Evidence to prepare

First step

Master exam preparation rewards candidates who separate what a question states from what a record supports. Method: for a motor model problem, list every voltage record, note its source, and resolve the scenario question and the evidence question separately. The scenario decides which voltage the problem intends; the evidence decides which record is trustworthy. Common misconception: when competing voltage records appear, average them or choose the larger one for safety. Correct practice: never merge records; resolve scenario and evidence in separate steps, record each outcome, and state the remaining assumption. Transfer: in a changed fictional paper case, the motor model names one supply while a nameplate sketch and a riser note show another; write both resolutions before computing.

Your attempt Members only
Try a changed case Members only
Evidence to prepare Members only

Members only

See membership

Practice for this step: 3 questions

Choose one answer per question. This practice runs in your browser.

A commercial building has both 208Y/120-volt and 480Y/277-volt feeders. How must the ungrounded feeder conductors be identified?

A feeder protected at 1,200 amperes runs as three parallel sets in three separate metal-free (PVC) raceways, each with its own wire-type copper equipment grounding conductor. The minimum phase conductors would be 600 kcmil per set, but 750 kcmil is installed to limit voltage drop. Copper EGC rows: not over 400 A, 3 AWG; not over 1,000 A, 2/0 AWG; not over 1,200 A, 3/0 AWG; not over 1,600 A, 4/0 AWG. Areas: 3 AWG 52.62 kcmil; 2 AWG 66.36 kcmil; 3/0 AWG 167.8 kcmil; 4/0 AWG 211.6 kcmil. What is the minimum EGC in each raceway?

A PV inverter is connected to a panelboard through a backfed circuit breaker. Which warning is typically required at that breaker?