PEC EPE Electrical case studies

PEC EPE Electrical · Put your knowledge to work in context.

The Engineering Practice Examination (EPE) is administered by the Pakistan Engineering Council (PEC) and appears in PEC's navigation under the Continuing Professional Development (CPD) section, where PEC also publishes an EPE Guidebook and a policy for redressal of EPE grievances. The credential is aimed at engineers moving from registration toward recognised professional practice; PEC's site separately lists engineer registration and the IPEA/Int.PE(PAK) route, and the EPE sits alongside those professional-development offerings. The PEC EPE Electrical case studies are 5 cases and about 3,266 words.

Transformer Differential Tripping on Energization with a Parallel Unit in Service

A 132/11.5 kV, 20/26 MVA ONAN/ONAF transformer T1 at a grid station was returned to service after tap-changer maintenance. Its 87T relay uses 500/1 CTs on the 132 kV side and 2000/1 CTs on the 11.5 kV side, a 30% slope, and second-harmonic blocking set at 15%.

699 words, about 3 min 2

Capacitor Bank Resonance with 6-Pulse VFD Loads on an 11 kV Bus

An 11 kV industrial bus supplies two 800 kW 6-pulse VFDs and a 2 MVA capacitor bank connected in two 1 MVA steps. The 11 kV source fault level is 50 MVA.

610 words, about 3 min 3

Motor Starting Voltage Dip and Starter Selection for a Loaded Conveyor

A 2 MW, 6.6 kV, 4-pole induction motor is to be started direct-on-line from a 6.6 kV switchboard fed by a 5 MVA, 11/6.6 kV transformer with 6.5% impedance. The 11 kV source fault level is 250 MVA.

624 words, about 3 min 4

Substation Earthing Compliance with High GPR and Transferred Potential

A 132/11 kV substation has a 70 m × 50 m earth grid of 150 mm² copper conductor at 0.8 m depth, with 12 meshes in each direction and four 3 m rods at the corners. Soil resistivity is 120 Ω·m to a measured depth of 20 m; a 100 mm layer of 3000 Ω·m gravel covers the switchyard.

638 words, about 3 min 5

Voltage Rise and Protection Coordination for a 5 MW PV Plant on a Radial 11 kV Feeder

A 5 MWp solar PV plant connects to the end of an 8 km, 11 kV radial feeder. The feeder conductor is 185 mm² ACSR with r = 0.35 Ω/km and x = 0.40 Ω/km.

695 words, about 3 min