Start with the airflow problem
Airflow problems can imitate refrigeration faults. Select the symptom and the installed airflow configuration before checking the refrigeration circuit.
PROBLEM TO DIAGNOSE
Choose the closest symptom. Exact alarm wording can be entered on the next screen.
UNIT AND AIRFLOW CONFIGURATION
Safety: Fans may start automatically and EC/VFD assemblies contain hazardous voltage. Use lockout/tagout and required electrical PPE before reaching into a fan, opening an electrical enclosure, or inspecting a wheel or motor.
Fast path: Confirm the installed and running fan counts, then answer only the checks you know. Relevant optional sections open automatically.
DISPLAYED INFORMATION
Optional. Type the alarm exactly as displayed.
AIR PATH CHECKS
STATIC PRESSURE AND TEMPERATURE
Use the same pressure units for setpoint, actual and deadband. Airflow Buddy calculates temperature difference as return minus supply.
Primary finding
Complete the conditions first
Fan Command / Actual—
Static Pressure—
Return − Supply—
WHAT SHOULD BE HAPPENING
MOST LIKELY CAUSES
DIAGNOSTIC ORDER
Field reminder: Do not diagnose refrigeration performance until fan operation, filter/coil condition, supply and return paths, control sensor selection and actual airflow have been verified.