How to Choose an Electrical Contractor in Nigeria: 8 Questions to Ask

Choosing an electrical contractor is one of the most important decisions a building owner or facility manager makes. The cheapest quote often becomes the most expensive job once faults, rework and downtime are counted. These eight questions help you tell a qualified contractor from one who will cut corners.

1. Are your engineers registered and qualified?

Ask who will design and sign off the work, and what their qualifications are. Engineering work in Nigeria should be led by engineers registered with the Council for the Regulation of Engineering in Nigeria (COREN). Ask to see evidence, and ask who will actually be on site.

2. What experience do you have with this kind of job?

Wiring a house, servicing an 11 kV ring main unit and assembling a 2,000 A distribution panel are very different jobs. Ask for examples of similar work, and for references you can call.

3. Will you assess the load and design the system first?

A good contractor surveys the site and assesses the load before quoting. A contractor who quotes without looking is guessing cable sizes, breaker ratings and generator capacity. Read why load assessment matters.

4. Which standards and regulations will you work to?

The contractor should be able to name the wiring regulations and standards they follow, and explain how the work will be inspected. Vague answers are a warning sign.

5. How will you test the installation before handover?

Every new or modified installation should be tested before it is energised: insulation resistance, continuity, earth resistance and protection checks as a minimum. Ask whether you will receive the test results in writing.

6. What materials and equipment will you use?

Ask for the make and rating of cables, breakers and panels in the quote. Undersized or counterfeit materials are one of the most common causes of failures and fires.

7. How do you manage safety on site?

A professional contractor works under permit-to-work and lock-out procedures, uses proper PPE and isolates supplies before work starts. This protects your staff as well as theirs. See our guide to safety rules in high-voltage areas.

8. What support do you give after the job?

Ask what happens if something fails after handover, whether the contractor offers planned maintenance, and whether there is an emergency number for out-of-hours faults.

Red flags to watch for

• A quote with no site visit
• No written scope, materials list or test results
• Pressure to pay everything up front
• Replacing tripping breakers with bigger ones instead of finding the cause
• No earth connection on equipment, or no plan for earthing

See a real example of what these shortcuts cost in our post on hiring the wrong electrician.

How Corustar answers these questions

Corustar Technological Services is an electrical engineering contractor working from the 33 kV intake to the final circuit. Our work is led by registered engineers, every job ends with recorded test results and a written report, and our test instruments are calibrated to BS EN ISO 10012. We cover HV/LV switchgear, transformers, cable jointing, LV panels, safety audits, earthing and 24/7 repairs.

Talk to Corustar

Corustar Technological Services is an electrical engineering contractor based in Ikeja, Lagos, working across Nigeria. See our About Corustar service, request a quote, or call +234 816 976 9672. For outages and faults, call our 24/7 emergency line on 0705 739 9297.