Why do generator changeover bids come in low in Qardho?

Generator changeover underbidding risks in Qardho start with scope, not price. A bid can look cheap because it covers only the switch and a short cable run, while the cable to the generator, earthing, enclosure, fuel bunding and fire separation sit outside it. Two bids for a set can differ by the equipment they assume, so compare priced scope before you compare totals.

Which items get left out of a low changeover bid?

A changeover bid often gets trimmed to the switch and the wall it mounts on. The generator sits outdoors for exhaust and cooling, so the cable run to the building, its route, trench or tray, and the cable size needed for voltage drop can all be missing. Earthing is another common omission: an earth electrode, conductor and test record cost money and labour, and a bid that assumes the building's existing earth may not match what the installation needs. Mounting, an enclosure against rain and sun, fuel bunding, fire separation, exhaust routing and signage can also fall outside the quoted line.

Ask each bidder for a priced schedule that lists the changeover switch, all cable by size and length, the earth electrode and conductor, the enclosure, supports, terminations, testing and commissioning as separate lines. Compare the schedules before the totals. Confirm cable sizes and earthing arrangements against the project's electrical drawings and specification, and ask the project engineer where the drawings are silent.

How does underbidding in Qardho change the installed work?

When the budget cannot carry the omitted items, someone substitutes. A smaller cable may be pulled to save copper, which raises voltage drop and heat at full load. The earth electrode may be dropped, or a rod driven without a test. The enclosure may be skipped so the switch sits exposed. Fuel pipes or drums may sit close to the exhaust because no one priced fire separation. On the changeover itself, a manual switch may replace an interlocked one, or the installer may rely on a warning sign. Any arrangement that allows the generator and the utility supply to connect at the same time can back-feed the line and put anyone working on it at risk.

Check what was actually installed against the schedule. Look for the cable size printed on the sheath, the earth conductor and its connection, the electrode and its test record, and the enclosure. Ask for the commissioning record showing the changeover operates and cannot connect both sources at once.

How do you test the changeover before final payment?

Start with the paperwork: the priced switch schedule, the cable route drawing, the earth electrode test record and the commissioning sheet. Then watch the changeover run. With the load connected, switch from the utility supply to the generator and back, and watch whether the changeover prevents both sources from feeding at once. Check that the earthing conductor is continuous from the switch to the electrode, and that the enclosure keeps rain and dust off live parts.

Where the specification does not state a cable size, earth resistance or switching arrangement, ask the project engineer to confirm the general practice figure for the installation and put it in writing before the work is accepted. Interlocking to prevent back-feed is general good practice, not a Qardho rule, so confirm what the project requires with the engineer. Ask the Qardho municipal engineer's office whether it holds records or requirements for generator installations in the town.

What to do next

Before you accept a generator changeover bid in Qardho, send every bidder the same written scope and ask for a priced schedule covering the switch, cable by size and length, earthing with test, enclosure, fuel containment, fire separation and commissioning. Compare the schedules, then walk a recent installation and ask to see its earth test record before you sign.