BAS-208 Visual Aid Library
Figure-use rule
Each figure is an orientation and reasoning aid, not a project drawing. Learners must pair it with the current sequence, point list, wiring/piping documents, manufacturer instructions, and as-found evidence.
Normal-rule anchor
Fabricators implement controlled design; they do not silently redesign protection, spacing, ratings, or interfaces.
Case overlay
The BOM and schematic disagree on transformer and relay models, and a shop substitute has no approval.
Calculation/evidence callout: Reconcile component/requirement counts, revisions, substitutions, and unresolved authority.
Normal-rule anchor
Layout follows function and service, not just geometric fit; every wire and device needs an identified role.
Case overlay
A relay contact is on the schematic but absent from the BOM and terminal schedule.
Calculation/evidence callout: Reconcile schematic devices/contacts/terminals/wires to BOM and layout with zero unexplained items.
Normal-rule anchor
A layout that fits with covers removed may fail when wireway covers, terminal access, heat, labels, and replacement are considered.
Case overlay
The controller fits but its removable connector cannot be accessed and a power supply heats the network switch.
Calculation/evidence callout: Calculate used/available area, wireway occupancy from supplied criteria, clearances, spare, and supplied heat budget.
Normal-rule anchor
Part-number similarity and physical fit are not compatibility or listing evidence.
Case overlay
A replacement relay has the wrong coil voltage and a terminal block excludes the specified conductor type.
Calculation/evidence callout: Compare all supplied rating/interface fields and calculate component/terminal quantities and fabrication checks.
Normal-rule anchor
Calculations support verification; they do not authorize learners to design upstream protection or parallel transformers.
Case overlay
Normal load is within VA but actuator startup and added accessories eliminate required spare margin.
Calculation/evidence callout: Compute VA/current by load and total, supplied demand/inrush cases, spare percentage, and delivered-voltage interface.
Normal-rule anchor
Ground, bond, common, reference, neutral, and shield are not interchangeable words or conductors.
Case overlay
The enclosure door lacks a bond while an MS/TP shield is used as a power common.
Calculation/evidence callout: Use supplied design to reconcile every intended connection and interpret continuity/resistance evidence within de-energized qualified procedures.
Normal-rule anchor
An SPD is not magic; location, rating, lead routing, grounding/bonding, coordination, maintenance, and exposure determine performance.
Case overlay
An exterior sensor and interbuilding trunk enter the panel with SPDs mounted far from the entrance and long ground leads.
Calculation/evidence callout: Compare supplied SPD ratings/exposure and calculate lead/path lengths, protected/unprotected interfaces, and replacement coverage.
Normal-rule anchor
Neatness and continuity are limited evidence; rating, terminals, torque, separation, controlled identity, first power, and field function remain distinct.
Case overlay
The panel looks orderly and wires beep, but chips, cut strands, duplicate numbers, a cross-connection, and wrong relay contact remain.
Calculation/evidence callout: Reconcile parts/wires/terminals/labels/tests, compare expected states/readings, and calculate defect, process, and reinspection coverage.
Normal-rule anchor
Shop completion does not authorize energization; critical missing source, protection, bond, short, setting, or record is a hold.
Case overlay
Delivery is due, but source voltage, one bond, protection setting, and debris inspection are unresolved.
Calculation/evidence callout: Calculate checklist and critical-item completion; no average overrides a hold condition.
Normal-rule anchor
A tested shop panel can still fail from transport, field power, grounding, entries, devices, network, configuration, or process; handoff states boundaries honestly.
Case overlay
The panel ships with a passed shop record but field source, network, device loads, and controller database are pending.
Calculation/evidence callout: Reconcile artifacts/tests/components/issues and calculate handoff completeness and OJL observation requirements.