WBCHSE HS Vocational Power case studies
WBCHSE HS Vocational Power · Put your knowledge to work in context.
The WBCHSE Higher Secondary Vocational (Power) credential is a West Bengal state-level higher-secondary vocational qualification for students who want a practical, trade-oriented route into electrical power work rather than a purely academic science stream. It suits learners aiming at helper or technician-entry roles in wiring, installation, machine maintenance, substation and distribution work, or at further study in electrical and power engineering. The WBCHSE HS Vocational Power case studies are 5 cases and about 4,985 words.
1Choosing a workshop submain cable when the base table rating looks generous
A licensed contractor sends you, a final-year vocational trainee, to complete the submain for a small fabrication workshop. The single-phase lighting circuits are already in place; the new three-phase submain must feed a welding socket, a 5 HP (3.7 kW) air compressor and a bench grinder, giving a connected load of 9 kW at an assumed power factor of 0.85.
957 words, about 5 min2A domestic 30 mA RCCB that trips after rain, and a tempting shortcut
A two-storey house wired in 2011 has a 30 A, 63 A two-pole RCCB as the main incoming device, with six MCB final circuits downstream and no earth-leakage protection on individual circuits. The owner reports that the RCCB trips two or three times a week, mostly at night, and reliably after rain.
994 words, about 5 min3A VFD retrofit on a pump that trips in the morning and reads a noisy signal
A 7.5 kW, 415 V, four-pole, 1440 rpm three-phase centrifugal pump motor, previously direct-on-line started, has been retrofitted with a 7.5 kW variable frequency drive to save energy on a partial-load duty. Commissioning data: motor full-load current 14.5 A; the drive's motor overload parameter was set to 14.5 A; acceleration ramp 3 s; minimum frequency 25 Hz; maximum 50 Hz.
1,061 words, about 5 min4A CT-operated energy bill that a clerk has multiplied twice
A small flour mill is supplied at 415 V, three-phase, four-wire, through three 200/5 A ring-type current transformers of class 1, connected to a three-phase four-wire static energy meter. In June the meter's kWh register advanced by 1240 kWh.
976 words, about 5 min5Quoting a coaching-centre wiring job when the client wants to cut corners
You have registered a small proprietorship electrical contracting firm after completing your HS Vocational course and hold a Wireman's licence. A coaching centre asks for a quotation to wire a rented two-storey building: six classrooms, two toilets and one office.
997 words, about 5 min