Technical Trade SchoolBAS-300 service-series
BAS-303
Concept reading and source route

BAS-303 Reading Guide

How to use this reading guide

This is the concept-review layer for a 100% online course. Read each module before its lesson, complete the retrieval prompts without looking, then use the linked authoritative sources to verify project-specific editions, requirements, and manufacturer procedures.

Online evidence is not OJL: browser simulations, document cases, and isolated remote equipment build reasoning and documentation skill; supervised field performance is recorded separately.

Module 1

Sequence sources, revision, and grammar

Why it matters: The newest guideline or program is not automatically the project sequence; applicability and revision must be proven.

Vocabulary and working scope

OPR/BOD awareness; contract sequence; addenda/RFI; submittal; controller program; operator narrative; shall/should; condition; action; limit; exception; authority.

Source-to-result trace

  1. Locate the controlling requirement and establish authority.
  2. Identify the physical and digital boundaries.
  3. Preserve as-found state and timestamps.
  4. Trace the initiating condition through logic, interfaces, equipment, and process response.
  5. Compare expected and actual evidence.
  6. Calculate with units and stated tolerance.
  7. Record action, result, restoration, uncertainty, and owner.

Worked thinking prompt

The approved sequence and current program disagree after an undocumented change.

Calculation: Reconcile clause, revision, program version, point list, and test record before deciding which difference is a fault.

Retrieval prompts

Module 2

Modes, states, and transitions

Why it matters: A sequence is more than output values; entry, steady behavior, exit, and transition priority must be explicit.

Vocabulary and working scope

Occupied; unoccupied; warm-up; cooldown; standby; enable; disabled; alarm; transition condition; entry action; steady action; exit; forbidden transition.

Source-to-result trace

  1. Locate the controlling requirement and establish authority.
  2. Identify the physical and digital boundaries.
  3. Preserve as-found state and timestamps.
  4. Trace the initiating condition through logic, interfaces, equipment, and process response.
  5. Compare expected and actual evidence.
  6. Calculate with units and stated tolerance.
  7. Record action, result, restoration, uncertainty, and owner.

Worked thinking prompt

An AHU remains in warm-up after zone temperatures satisfy the exit condition.

Calculation: Evaluate Boolean transition conditions and elapsed time in the stated order and priority.

Retrieval prompts

Module 3

Permissives, interlocks, safeties, fallback, and restart

Why it matters: Optimization never outranks life safety, equipment protection, or defined fallback behavior.

Vocabulary and working scope

Enable chain; proof; lockout; freeze; smoke interface; minimum flow; communication loss; sensor failure; fallback value; restart delay; manual reset.

Source-to-result trace

  1. Locate the controlling requirement and establish authority.
  2. Identify the physical and digital boundaries.
  3. Preserve as-found state and timestamps.
  4. Trace the initiating condition through logic, interfaces, equipment, and process response.
  5. Compare expected and actual evidence.
  6. Calculate with units and stated tolerance.
  7. Record action, result, restoration, uncertainty, and owner.

Worked thinking prompt

A fan restart is requested immediately after power recovery while dampers have not proven position.

Calculation: Calculate delay and proof windows and build a truth table for permissives, trips, fallback, and restart.

Retrieval prompts

Module 4

Setpoints, deadbands, hysteresis, and timers

Why it matters: Deadband separates actions around a target; hysteresis and timers prevent unstable repeated switching.

Vocabulary and working scope

Effective setpoint; source; limits; offset; deadband; differential; hysteresis; on/off delay; minimum on/off; debounce; persistence; anti-short-cycle.

Source-to-result trace

  1. Locate the controlling requirement and establish authority.
  2. Identify the physical and digital boundaries.
  3. Preserve as-found state and timestamps.
  4. Trace the initiating condition through logic, interfaces, equipment, and process response.
  5. Compare expected and actual evidence.
  6. Calculate with units and stated tolerance.
  7. Record action, result, restoration, uncertainty, and owner.

Worked thinking prompt

Heating and cooling commands alternate every minute near the zone setpoint.

Calculation: Calculate upper/lower thresholds, elapsed persistence, minimum run/off time, and expected next transition.

Retrieval prompts

Module 5

PID action and tuning evidence

Why it matters: Correct direct/reverse action and trustworthy sensors/actuators/process are verified before gain changes.

Vocabulary and working scope

Process variable; setpoint; error; output; direct/reverse action; proportional gain/band; integral; derivative awareness; saturation; windup; sample time; disturbance.

Source-to-result trace

  1. Locate the controlling requirement and establish authority.
  2. Identify the physical and digital boundaries.
  3. Preserve as-found state and timestamps.
  4. Trace the initiating condition through logic, interfaces, equipment, and process response.
  5. Compare expected and actual evidence.
  6. Calculate with units and stated tolerance.
  7. Record action, result, restoration, uncertainty, and owner.

Worked thinking prompt

A cooling-valve loop drives closed when discharge temperature rises above setpoint.

Calculation: Calculate signed error and proportional response using the supplied controller convention; conventions must be stated.

Retrieval prompts

Module 6

Reset equations, limits, and interpolation

Why it matters: A reset schedule is an equation with limits and applicability, not a line copied from another project.

Vocabulary and working scope

Outdoor-air reset; load reset; linear interpolation; high/low endpoints; clamps; enable range; sensor failure; schedule interaction.

Source-to-result trace

  1. Locate the controlling requirement and establish authority.
  2. Identify the physical and digital boundaries.
  3. Preserve as-found state and timestamps.
  4. Trace the initiating condition through logic, interfaces, equipment, and process response.
  5. Compare expected and actual evidence.
  6. Calculate with units and stated tolerance.
  7. Record action, result, restoration, uncertainty, and owner.

Worked thinking prompt

The SAT reset calculates below the approved low limit during mild weather.

Calculation: Use y=y1+(x−x1)(y2−y1)/(x2−x1), then apply enable conditions and high/low clamps.

Retrieval prompts

Module 7

Requests and trim-and-respond

Why it matters: A high request count may represent one upstream fault or bad data; validate request identity and quality before responding.

Vocabulary and working scope

Zone request; severity; persistence; aggregation; ignored zones; trim; respond; interval; limits; hold; startup; sensor/data quality; reset target.

Source-to-result trace

  1. Locate the controlling requirement and establish authority.
  2. Identify the physical and digital boundaries.
  3. Preserve as-found state and timestamps.
  4. Trace the initiating condition through logic, interfaces, equipment, and process response.
  5. Compare expected and actual evidence.
  6. Calculate with units and stated tolerance.
  7. Record action, result, restoration, uncertainty, and owner.

Worked thinking prompt

Static pressure rises to maximum because several boxes generate persistent requests from failed airflow sensors.

Calculation: Calculate request count/severity, interval-based trim/respond steps, clamps, and time to target from supplied rules.

Retrieval prompts

Module 8

Point implications, state tables, and evidence maps

Why it matters: A testable sequence connects narrative requirements to specific point identities, physical observations, time, and expected results.

Vocabulary and working scope

Required inputs; outputs; calculated points; commands; proofs; alarms; trends; quality; units; sampling; physical result; missing point.

Source-to-result trace

  1. Locate the controlling requirement and establish authority.
  2. Identify the physical and digital boundaries.
  3. Preserve as-found state and timestamps.
  4. Trace the initiating condition through logic, interfaces, equipment, and process response.
  5. Compare expected and actual evidence.
  6. Calculate with units and stated tolerance.
  7. Record action, result, restoration, uncertainty, and owner.

Worked thinking prompt

The sequence requires fan proof and airflow response, but the database contains only a fan command.

Calculation: Build a state/point matrix and reconcile required, available, trustworthy, and missing evidence counts.

Retrieval prompts

Module 9

Deviation diagnosis and change authority

Why it matters: A technician may diagnose a design/program deviation without gaining authority to rewrite the design.

Vocabulary and working scope

Sequence ambiguity; program defect; configuration; bad sensor; actuator/mechanical; timing; priority; document conflict; design/application question; owner decision.

Source-to-result trace

  1. Locate the controlling requirement and establish authority.
  2. Identify the physical and digital boundaries.
  3. Preserve as-found state and timestamps.
  4. Trace the initiating condition through logic, interfaces, equipment, and process response.
  5. Compare expected and actual evidence.
  6. Calculate with units and stated tolerance.
  7. Record action, result, restoration, uncertainty, and owner.

Worked thinking prompt

A reset loop follows the current program exactly but conflicts with the approved sequence.

Calculation: Compare expected and actual states across identical conditions and quantify the deviation, timing, and affected modes.

Retrieval prompts

Module 10

Test vectors, functional evidence, and restoration

Why it matters: A valid test defines initial state, manipulation, expected response, tolerance/time, evidence, result, and restoration.

Vocabulary and working scope

Initial conditions; input vector; manipulation; expected state/output/time/tolerance; evidence; pass/fail/blocked; issue; retest; restore; changed-case test.

Source-to-result trace

  1. Locate the controlling requirement and establish authority.
  2. Identify the physical and digital boundaries.
  3. Preserve as-found state and timestamps.
  4. Trace the initiating condition through logic, interfaces, equipment, and process response.
  5. Compare expected and actual evidence.
  6. Calculate with units and stated tolerance.
  7. Record action, result, restoration, uncertainty, and owner.

Worked thinking prompt

A sequence test passes one steady state but never tests transition, failure, or restart behavior.

Calculation: Reconcile required vectors, executed vectors, pass/fail/blocked, retested, and restored states; critical vectors cannot be averaged away.

Retrieval prompts

Required and deeper reading

Adoption note: Standards, codes, project requirements, owner criteria, manufacturer instructions, and employer safety programs control. Confirm the adopted edition and authority before applying a numeric requirement.