Lessons Learned: Documentation As-Built Miss-Alignment (Wind Farm Electrical)

The dispute involved a large-scale wind farm where turbines had been updated and delivered with pre-wired masts suitable for the previous model. Substantial re-wiring occurred onsite. We were engaged independently to opine on entitlement and quantum under an electrical installation subcontract.

Field conditions repeatedly conflicted with the manual: hoist access constraints; LV earth bar located under floor plates (confined-space terminations); UPS installed one level higher and factory pre-wiring incorrect; transformer–converter cables supplied at mismatched lengths; cable-tray path had to be re-worked by rope access inside the mast; cable bundles increased (6→7) and diameters up-sized; armour-casting sheathing missing from the kit; site allowance impacts followed.

We mapped manual vs as-installed conditions and valued discrete tasks under Schedule E—testing claimed hours against trade-level effort and access constraints—then rolled up allowances. Examples: hoist access hours; UPS rewiring 4 h/WTG; transformer–converter cable corrections; site allowance in man-days. We explained why these were scope changes (not mere productivity).

• Treat OEM deviations as variations early, not as “efficiency” issues.

• Lock a simple, hour-based pathway (rate + allowance) for document-driven changes and keep signed field directions.

• De-risk access: plan for hoist/rope-access when cabinet locations/levels differ from drawings.

• Where factory pre-wiring/cable sets vary, pre-agree a rectification matrix (hours per WTG) to avoid serial disputes.

Note: In the material reviewed, our report reframed the dispute around documentation–as-built divergence, enabling clean, rate-based resolution rather than a productivity argument.