ETAP ↔ AutoCAD data bridge

Context

Power-system studies in ETAP and single-line geometry in AutoCAD describe the same low-voltage plant on paper and routinely drift in practice. The studio built a data bridge as a tool, listed under Work, adjacent to engineering automation. It is not a claim that every ETAP licence on earth should be wired this way; it is a record of one integration approach.

Limits of this note

The bridge was a mapping with a conflict list, not a hidden plugin that overwrote drawings on every click. ETAP kept electrical parameters used in the study. AutoCAD kept geometry and annotation the study does not compute. Units were explicit. Ratings the source did not supply were not invented. Prototype width was a feeder, then more of the plant, never a campus on day one.

Where the tool was used, drift became a review item: in the model not on the sheet, on the sheet not in the model, same key different rating. Where it was not used, the weekly spreadsheet remained. No percentage of time is offered. No vendor endorsement is implied beyond the fact that both applications already existed in the studio workflow.

A document-centric platform is a different build. This case is only the identity problem between a power-system model and a single-line. Keeping that boundary honest is the outcome that matters for anyone considering a similar bridge.

Problem

Equipment names, ratings and topology were typed twice. A study revision did not automatically visit the drawing. A drafting cleanup did not visit the model. The weekly spreadsheet in the middle was itself a third schema. Silent drift is the failure mode: a coordination study that no longer matches the sheet issued to site.

Approach

Name a shared identity for each studied object. Decide which fields ETAP owns (electrical parameters used in the study) and which AutoCAD owns (geometry, layers, annotation that the study does not compute). Map units explicitly. Refuse to invent a rating the source did not supply. Prototype on a feeder, then widen. General pattern: connecting engineering applications. Scoping test: when it is worth building.

Architecture

An extract/transform/load path with a versioned mapping, not an opaque plugin that overwrites the drawing on every click. Conflicts surface as a list: in ETAP not in CAD, in CAD not in ETAP, same key different rating. The bridge does not replace either vendor application. A broader document store is a different build: EE-Platform.

Outcome

On the jobs that used the bridge, the single-line and the analysis model stopped being unrelated documents. Remaining differences were visible and assignable. No revenue figure, no percentage of time, no client name. The qualitative result is the one that matters for this class of tool: drift became a review item instead of a surprise.