BAS-201 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
Cable is part of a complete physical/digital control path; current approved documents and exact equipment information precede material choice.
Case overlay
The point list calls for a duct sensor, the drawing and cable schedule disagree on controller input and cable tag, and a field note is unsigned.
Calculation/evidence callout: Reconcile requirement coverage, document revisions, endpoints, interfaces, and unresolved items; no silent assumption closes the map.
Normal-rule anchor
Twenty-four volts does not by itself establish circuit classification or wiring method, and familiar cable appearance is not product proof.
Case overlay
The nearest reel is 18/2 shielded and the jacket color looks right, but the specified circuit needs three conductors and wet-location suitability.
Calculation/evidence callout: Calculate conductor/load needs and compare every required rating and construction field to supplied product data.
Normal-rule anchor
Color improves recognition but never proves cable suitability, circuit class, polarity, terminal function, or approval; independent text/source evidence controls.
Case overlay
A yellow cable matches the analog-input legend but its printed construction is wrong; a blue cable is technically correct and has a documented substitution.
Calculation/evidence callout: Score the identity stack for agreement/conflict and account for every cable by tag, part, endpoints, route, and approval.
Normal-rule anchor
Replace slogans with the actual approved wiring method; cable listing, space, support, separation, damage exposure, specification, and AHJ determine the route.
Case overlay
The shortest path lies on ceiling grid wire, parallels VFD output leads, crosses a rated wall, and enters a wet mechanical space.
Calculation/evidence callout: Calculate route length and service allowance, compare support/pathway capacity, and identify every boundary requiring coordination or BAS-202 transfer.
Normal-rule anchor
Common, earth, equipment grounding, signal reference, and shield are different unless the approved design connects them.
Case overlay
Several sensors drift when a VFD runs, and a shield drain was used as a spare common at one device.
Calculation/evidence callout: Apply Ohm/power relationships and supplied signal ranges; compare expected source, loop, reference, and controller readings with units.
Normal-rule anchor
Mechanical damage can degrade a cable without obvious failure; exact product handling limits and approved pathway readiness govern.
Case overlay
A pathway contains a sharp edge and standing water, while the pull crew has no communication or stop signal.
Calculation/evidence callout: Calculate pull length and slack from supplied dimensions, compare bend/tension limits, and inventory pre/post-pull defects.
Normal-rule anchor
Accessories and torque are terminal/product/process specific; universal ferrule, tinning, or torque rules are unsafe shortcuts.
Case overlay
A stranded conductor has cut strands, excess bare copper, an unapproved ferrule, and no torque/process record.
Calculation/evidence callout: Compare strip/exposure and conductor counts to supplied limits; calculate defect/rework rates and verify every terminal identity.
Normal-rule anchor
Every calculation states source, units, assumptions, complete current path, minimum criterion, margin, inrush/temperature limitations, and reasonableness.
Case overlay
A 24 Vac transformer serves three actuators at a long run, and the farthest device resets during simultaneous startup.
Calculation/evidence callout: Compute I=VA/V, total load, loop resistance, Vdrop=IR, delivered voltage, percent drop, and remaining source capacity.
Normal-rule anchor
A continuity beep, BAS value, or visual landing is one evidence layer; no single test proves complete identity and function.
Case overlay
Continuity passes end-to-end, but the point is on the wrong terminal and fails only when the cable is moved.
Calculation/evidence callout: Compare measured resistance/voltage to predicted ranges and calculate discrimination value, uncertainty, and retest coverage.
Normal-rule anchor
Documentation is part of the installed control path; a neat cable without controlled identity and evidence is unfinished work.
Case overlay
Ceilings will close tomorrow, but three labels, a route change, and one failed conductor test are not reconciled.
Calculation/evidence callout: Reconcile planned/installed/tested/passed/failed/reworked/as-built counts and calculate record completeness before release.