Return air temperature sensor may be faulty

Objective/Method/Outcome

Objective: Determines if the return air temperature is faulty.

Method: Checks if the sensor is faulty by monitoring the changes in the value of the sensor or if the temperature is out of range for more than the acceptable amount of time

Outcome: Triggers an insight when it determines the sensor is faulty.

Applicable System

RAF

Description

Sensor validation rule: Check for unreliable readings in range and quality. This rule is part of the CopperTree Standard rule-set.

Diagnosis

  1. Verify sensor exists.
  2. Verify sensor has power.
  3. Verify reading in BMS.
  4. Replace if the sensor is broken.

Message

The return temperature sensor is reading outside reasonable range or is stuck on one value. This may negatively impact comfort or energy efficiency.

Rule Template

Insight Type: Fault Detection

Trigger Type: Active High

Defualt Priority

Low

Logic

Logic used to determine if return air temperature is faulty

Inputs

Input Unit Tags Description
Return Air Temperature °C/ °F Return Air Temperature The recorded Return Air temperature
Temperature Low Limit °C/ °F The predetermined low limit for temperature
Temperature High Limit °C/ °F The predetermined high limit of temperature
Weekly Insight Threshold hours This is the minimum number of hours the system should be at fault to trigger insight

Notes

Default Thresholds:

  • Temperature Low Limit [°C]: 0°C or 32°F
  • Temperature High Limit [°C]: 40°C or 100°F
  • Weekly Insight Threshold [hours]: 120 hours