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gh-ctvet-cert-ii-electrical study materials
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gh-ctvet-cert-ii-electrical: Electrical Drawing, Wiring Diagrams and Documentation

gh-ctvet-cert-ii-electrical · Work through your exam, one topic at a time.

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Electrical Drawing, Wiring Diagrams and Documentation

Electrical Drawing, Wiring Diagrams and Documentation tests your ability to read, interpret and produce installation information. Questions cover drawing types, standard symbols, title blocks and revisions, single-line diagrams, cable schedules, test certificates and handover documents.

Core rules

  • Drawing types: block diagram (function only), schematic or circuit diagram (electrical logic), wiring diagram (physical connections and terminal numbers), layout or installation drawing (positions in the building), single-line diagram (three-phase systems condensed to one line), cable schedule and as-built drawing.
  • Symbols follow IEC 60617. Learn the common set: lamp, switch, two-way switch, socket outlet, distribution board, MCB, RCD, contactor, motor, transformer, earth.
  • The title block carries the drawing number, revision, scale, date, project, and who drew and checked it. Always work to the latest revision.
  • Documentation pack: installation certificate, minor works certificate, schedules of test results, permits, operation and maintenance manuals, warranties and as-built markups.
  • Read systematically: title block, then legend, then main circuit, then control circuit, then terminal and cross-references.

Worked example: two-way switching

A schematic shows two changeover switches controlling one lamp. In the wiring diagram, the permanent live goes to the common terminal of switch 1. Strappers run from L1 and L2 of switch 1 to L1 and L2 of switch 2. The common of switch 2 feeds the lamp, and the neutral runs directly to the lamp. With both switches on L1 the circuit is made; toggling either switch moves the path to the other strapper, breaking and remaking the circuit. Keep strapper core colours identical at both ends and label them as a pair.

Traps

  • Treating a schematic as a wiring diagram; one shows function, the other shows physical terminals.
  • Working from a superseded revision because the title block was not checked.
  • Mixing terminal numbers on multi-gang or intermediate switches.
  • Handing over without as-built drawings and test schedules.
  • Skipping the legend and misreading an unfamiliar symbol.

Professional Practice, Entrepreneurship and Employability

Professional Practice, Entrepreneurship and Employability tests whether you can operate as a competent, lawful and commercially viable electrical worker in Ghana. Questions cover regulatory bodies, contracts and quotations, costing, record keeping, customer care, workplace conduct and continuing development.

Core rules

  • Regulatory context: CTVET certifies competency-based TVET programmes; the Energy Commission regulates electrical wiring and electrician licensing; Electricity Company of Ghana and NEDCo set connection requirements; the EPA governs waste disposal.
  • A quotation is an offer. It should state scope, materials, price, payment terms, programme, validity period, exclusions and warranty. Work starts after written acceptance, not a verbal promise.
  • Estimating: material take-off, labour hours times rate, transport, plant, overhead, contingency, profit, then VAT and levies at the prevailing rate.
  • Business basics: register with the Registrar General's Department, obtain a TIN from the Ghana Revenue Authority, keep a cash book and receipts, insure against public liability, and keep client records confidential.
  • Employability: punctuality, safe work, clear communication, teamwork, honesty, respect for client property, and willingness to update skills.
  • Ethics: only undertake work you are competent and licensed for; refuse bribes; do not cut corners to win a job.

Worked example: quotation

Materials GH¢1,200; labour 3 days at GH¢150 = GH¢450; transport GH¢80. Direct cost = GH¢1,730. Overhead at 10 percent = GH¢173; profit at 15 percent of direct cost = GH¢259.50. Subtotal = GH¢2,162.50. VAT at 15 percent = GH¢324.38. Total = GH¢2,486.88, valid for 30 days, with payment terms and exclusions stated in writing.

Traps

  • Quoting from memory without a material take-off, then losing money on the job.
  • Omitting transport, overhead, warranty or tax from the price.
  • Starting work without signed acceptance and agreed payment stages.
  • Taking on work outside your licence class or competence.
  • Failing to keep receipts, which destroys your ability to prove costs and pay tax correctly.