Technical Trade SchoolBAS-300 service-series
BAS-306
Ten concept and evidence figures

BAS-306 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.

Figure 1 — Secure remote session and workspace critical

Normal-rule anchor

Remote convenience never removes authorization, target control, audit, or restoration requirements.

Case overlay

A learner sees two similarly named JACEs and is unsure which one is the assigned training target.

Calculation/evidence callout: Reconcile reservation time, login/logout, target count, actions, and access-closure log.

Figure 2 — Hierarchy, equipment, and point identity

Normal-rule anchor

A familiar point name is not sufficient identity; equipment, source controller, object/instance, units, and location must agree.

Case overlay

Two AHUs both contain a point named SAT and one graphic is bound to the wrong object.

Calculation/evidence callout: Reconcile point-list, controller-object, database, graphic, and equipment identities with zero unresolved duplicates.

Figure 3 — Command, output, action, proof, and process critical

Normal-rule anchor

A front-end command or animated graphic does not prove physical action or process result.

Case overlay

The fan command is on and the graphic fan icon is green, but duct static remains zero.

Calculation/evidence callout: Compare expected versus actual response at each chain link and record the last proven link.

Figure 4 — Reliability, freshness, timestamps, and quality critical

Normal-rule anchor

A plausible value without current timestamp, quality, and source evidence may be more dangerous than an obvious fault.

Case overlay

An outdoor-air temperature remains 55°F through a large weather change and shows no visible alarm.

Calculation/evidence callout: Calculate data age, clock offset, sampling interval, and event alignment before comparing points.

Figure 5 — Schedules, calendars, modes, and exceptions

Normal-rule anchor

The displayed weekly schedule may not be the effective command when calendars, exceptions, optimum logic, or local overrides apply.

Case overlay

The building is unoccupied on a Tuesday despite a normal occupied weekly schedule.

Calculation/evidence callout: Calculate effective start/stop and exception duration using supplied timezone, calendar, and precedence data.

Figure 6 — Trend design and interpretation

Normal-rule anchor

Trend more intentionally, not merely more: each point and interval must support a hypothesis or required context.

Case overlay

A VAV complaint lasts three minutes, but the trend interval is fifteen minutes and mixed time bases are used.

Calculation/evidence callout: Select sample interval from event duration and calculate rate, lag, duty cycle, and simultaneous-state windows.

Figure 7 — Alarm lifecycle, routing, and triage critical

Normal-rule anchor

Acknowledging an alarm changes workflow state; it does not remove the underlying condition.

Case overlay

A low-temperature alarm repeatedly returns after acknowledgment and is routed to the wrong team.

Calculation/evidence callout: Calculate alarm persistence, chatter frequency, deadband crossing, delay, and response time from event records.

Figure 8 — Overrides, priorities, and relinquish behavior critical

Normal-rule anchor

Clearing an override without knowing the next effective priority and physical impact can create a new fault.

Case overlay

A damper remains at 100% after the visible operator override is released.

Calculation/evidence callout: Reconcile every active priority, source, timestamp, expiration, and effective result before and after release.

Figure 9 — Offline cascades and stale graphics

Normal-rule anchor

Alarm count is not fault count; one upstream loss can create many derived or stale point symptoms.

Case overlay

Fifty point alarms appear at the same second after one field controller loses communication.

Calculation/evidence callout: Group events by timestamp and dependency; compare unique root events to downstream alarm count.

Figure 10 — Remote diagnosis, restoration, and handoff critical

Normal-rule anchor

A remote diagnosis is complete only when technical states and cyber access are both restored or explicitly transferred.

Case overlay

The training fault is corrected, but a forced point and active remote account remain after logout.

Calculation/evidence callout: Reconcile session actions, captures, changes, overrides, alarms, restored baseline, and access closure; all critical states must close.