Maharashtra HSC Electrical Technology (Vocational) case studies
Maharashtra HSC Electrical Technology (Vocational) · Put your knowledge to work in context.
The Maharashtra HSC Electrical Technology (Vocational) is a higher secondary vocational subject offered under the Maharashtra State Board of Secondary and Higher Secondary Education. It is designed for students who want a school-level qualification with a genuine trade skill attached: the syllabus blends basic electrical theory with wiring practice, machine work, measurement, installation and safety, so a candidate leaves able to read a circuit, select a cable, test an installation and work safely near live equipment. The Maharashtra HSC Electrical Technology (Vocational) case studies are 5 cases and about 4,170 words.
1Lathe Circuit: Voltage Drop and Derating in a Shared Conduit
A vocational institute's machine shop has just added a lathe driven by a 3 kW, 230 V, single-phase capacitor-start motor. At full load the motor draws 16.3 A at a power factor of 0.80.
782 words, about 4 min2Overloaded 500 kVA Transformer and Power-Factor Correction
A cooperative industrial estate is supplied by a 500 kVA, 11 kV/415 V, Dyn11 distribution transformer with an off-circuit tap changer on the nominal tap. Summer measurements taken at the transformer secondary during the peak shift show a line current of 740 A, a power factor of 0.75 lagging (active power about 400 kW), a top-oil temperature of 86 °C and an ambient of 43 °C.
785 words, about 4 min3Negative Wattmeter Reading on a Grinding-Machine Motor
During a load survey in a vocational workshop, a 7.5 kW, 415 V, 4-pole squirrel-cage motor driving a grinding machine is tested by the two-wattmeter method. The wattmeter in the R line reads 2.4 kW; the wattmeter in the B line reads −0.4 kW.
715 words, about 4 min4Recurring 30 mA RCCB Trips in a Wet Workshop
A polytechnic workshop is fed from an 8-way sub-distribution board whose incomer is a 4-pole, 63 A, 30 mA residual current circuit breaker. Downstream are eight 6 A switched socket outlets in the machine shop, a 1.5 kW wash-area pump, and an inverter welding set.
918 words, about 5 min5Estimating a 6 m × 9 m Machine Shop Installation
A 6 m × 9 m machine shop in a vocational institute is to be wired, and the institute wants an estimate before calling for quotations. The agreed requirements are: 10 LED fittings of 36 W each on two lighting circuits; six 16 A switched socket outlets on two circuits; one 3.7 kW, 415 V three-phase lathe; one 1.5 kW, 230 V compressor; and a 2 kW, 230 V water heater in the adjoining washroom.
970 words, about 5 min