In brief
- A low circuit protection bid usually means items were left out of the tender, not that the contractor works cheaply.
- The device schedule, breaker ratings and earthing must match the distribution design before you compare prices.
- Ask for the bill of quantities, the distribution board schedule and test records on a recent job before you sign.
Contents
A low circuit protection bid in Berbera often hides missing items rather than low prices. Circuit protection underbidding risks start when an estimator prices only the visible parts, such as the panel board, and leaves out breakers, enclosure boxes, earthing, cable glands, labels and testing. The submitted total then looks cheaper than a complete bid, and the difference only appears once the work starts.
What gets left out of a circuit protection price?
A complete circuit protection package covers more than the board itself. The bill of quantities should list each distribution board, the main incoming device, every outgoing breaker with its rating and type, busbars, neutral and earth links, enclosure and gland plates, cable terminations and labels. It should also carry the separate lines that estimators drop under pressure: earthing conductor, earth electrodes or mats, bonding of metallic services, surge protection where the specification asks for it, and the testing and commissioning time at the end. Ask the person pricing the job to walk you through the bill line by line and name the device for each circuit. If a line says "electrical works" or "protection, allowance", treat it as undefined. Ask the local authority what documentation a completed electrical installation must carry, and ask for a sample of that documentation from a recent job.
How do mismatched protective devices show up?
A breaker that trips at the wrong current, or a device type that does not match the cable and the load, is a design failure even when the parts are new. Common causes are breakers bought to a lower rating than the schedule, one type of device used across circuits with different loads, and no coordination between the main incoming device and the outgoing breakers. When ratings do not match the cable, the cable can carry more current than the breaker will allow, or the breaker can trip on normal load and be bypassed on site. In hot, dusty coastal conditions, enclosures need the correct IP rating and glands need to suit the cable, which is a general practice point to confirm against the project's specification. Where two protective devices sit in series, a fault should trip the device nearest the fault first, and a coordination check is the way to confirm that. Ask for the distribution board schedule, the cable sizes and the device settings, then compare them against each other.
What should a client ask for before comparing prices?
Compare bids on the same scope, not on the same total. Send every bidder the same distribution board schedule and the same bill of quantities, and require a priced line for each item, including testing and labelling. Ask each bidder to state in writing what the price excludes, such as trenching, conduit, cable supply or the earthing materials. Request test records from a recent completed job: insulation resistance, earth continuity and, where the supply permits, a trip test of each device. Walk a site the bidder has finished and look at whether the enclosure labels match the schedule and whether the earth bar has more than one connection. Check what the contract allows if the scope turns out to be incomplete, and take advice before you sign anything you cannot vary later.
What to do next
Send the same distribution board schedule and bill of quantities to two or three bidders and ask each one to price every line, state exclusions in writing and provide test records from a recent job. Then compare the priced lines, not the totals, and take advice on what your contract allows if the scope is incomplete.
Frequently asked questions
Is a low circuit protection bid always a problem?
No. A bid can be low because the contractor is efficient or already has the materials. The risk appears when the low total comes from missing lines, so compare item by item against the schedule before you judge it.
What is the quickest way to check a breaker matches the design?
Put the distribution board schedule beside the installed breakers and check the rating, type and circuit number against the cable size and the load for that circuit. Ask for the test records that confirm the device trips as designed.
Who should check the earthing and bonding in Berbera?
Confirm the local authority's record requirements for a completed installation, and require the contractor to show earth continuity test results before handover.
Local reporting: this article is written for building work in Berbera and Somaliland. Ground conditions, prices and rules differ between places; confirm the details for your own site.