Zone air carbon dioxide (CO2) sensor may be faulty

Objective/Method/Outcome

Objective: Checks for unreliable readings of Zone air CO2 sensor

Method: Checks the zone carbon dioxide reading to determine if it is out of range. The 24-hour maximum and minimum are also determined. If the maximum and minimum reading was constant or the zone carbon dioxide was constantly out of acceptable range, for more than the acceptable amount of time, an insight is triggered.

Outcome: Triggers an insight if zone air carbon dioxide sensor is determined to be faulty.

Description

Sensor validation rule: Check for unreliable readings in range and quality.

This rule is part of the CopperTree Standard ruleset.

Default Priority

Low

Diagnosis

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

Message

Zone carbon dioxide 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

Logic

Logic used to determine if zone carbon dioxide sensor is faulty

Inputs

Input Unit Tags Description
Zone Carbon Dioxide ppm Room CO2 The recorded zone carbon dioxide
Zone Carbon Dioxide Low Limit ppm   The lower limit of acceptable zone carbon dioxide range
Zone Carbon Dioxide High Limit ppm   The upper limit of acceptable zone carbon dioxide range
Weekly Insight Threshold Hr   The minimum acceptable hours of fault that can trigger an insight

Notes

Default Thresholds:

  • Zone Carbon Dioxide Low Limit [ppm]: 200 ppm
  • Zone Carbon Dioxide High Limit [ppm]: 2000 ppm
  • Weekly Insight Threshold [hours]: 120 hours