PE Electrical Power case studies
PE Electrical Power · Put your knowledge to work in context.
The Principles and Practice of Engineering (PE) Electrical and Computer: Power exam is one of the discipline-specific PE examinations NCEES administers for engineers pursuing professional licensure. NCEES describes the PE exam as testing for a minimum level of competency in a particular engineering discipline, and it is designed for engineers who have gained a minimum of four years of post-college work experience in their chosen engineering discipline. The PE Electrical Power case studies are 5 cases and about 2,706 words.
1Two-Wattmeter Measurement and Capacitor Sizing
At a 480 V, three-phase, three-wire industrial service, a technician uses the two-wattmeter method to measure a balanced motor load. With current coils in lines A and C and voltage coils connected A-B and C-B, the meters read W1 = 12.5 kW and W2 = 4.0 kW.
540 words, about 3 min2Induction Motor Starting at Reduced Bus Voltage
A 500 hp, 4,160 V, 60 Hz, three-phase induction motor drives a conveyor that requires 60% of rated torque at standstill and during acceleration. The motor has a locked-rotor torque of 110% of rated torque and a locked-rotor current of 5.5 times full-load current.
511 words, about 3 min3Feeder Voltage Drop and Capacitor Bank Justification
A 12.47 kV, three-phase, four-wire overhead feeder supplies a 3.6 MW, 1.74 Mvar lagging load at a distance of 2.5 miles from the substation. The line impedance is 0.35 + j0.75 Ω per mile.
495 words, about 2 min4Fault Duty and Relay Setting with a New Generator
A 2.5 MVA, 13.8 kV/480 V, 5.5% impedance transformer is protected on the 13.8 kV side by a 51 relay with a 150:5 CT. The relay has a 5 A nominal current and available taps of 1, 2, 3, 4, 5, 6, 8, and 10 A.
611 words, about 3 min5Capacitor Resonance and VFD Overvoltage
A 480 V plant has a 1,000 kVA transformer with 5.75% impedance and a 600 kvar shunt capacitor bank at the main bus. A new 200 hp, 6-pulse PWM variable-frequency drive is installed on a 150 ft motor cable.
549 words, about 3 min