Determine if temperature sensor is faulty
Applicable Systems
- Primary: AHU, RTU, MUA, ERV, BLR, CHLR
- Secondary: HP, FCU, UV, UH
Description / Method
Monitors temperature sensor readings and triggers an insight if the reading is outside of an acceptable range (0 to 45 deg C) for more than 2 hours a week (user adjustable). This temperature sensor readings are analyzed only when the equipment is on (example: Supply Air Temperature, Mixed Air Temperature), or when the space is occupied (Room Temperature).
Logic
Normalize inputs to 15 min intervals. Check the temperature is out of range. Filter results where equipment is not on or the building is not occupied. Sum these hours over the week. Store the weekly hours in a CTL.
CTL = sum hours over the week {
when occupired {
temp Out of range = if(Temp> high limit or temp < low limit)
}
}
if(Sum > threshold, Insight)
Diagnosis / Recommended Action
- Input sensor(s) faulty or miscalibrated. Verify input sensor(s) operation.
Message
The Temperature sensor is faulty (outside of acceptable range). Verify input sensor operation.
Rule Template Type
- Insight Type: Fault Detection
- Trigger Type: Active High
Default Priority
Low
Inputs
| Inputs | Units | Tags | Description |
|---|---|---|---|
| Temperature | °C/°F | mixed|discharge|return|fresh|room|zone,air,temp,sensor | Equipment On/Off Indicator |
| Equip ON | 0/1 | cmd|status|occupied | Desired temperature of water leaving the chiller |
Constants
| Inputs | Units | Default Value | Description |
|---|---|---|---|
| High Threshold | °C/°F | 45 | Upper limit on allowed reported temperature |
| Low Threshold | °C/°F | 0 | Lower limit on allowed reported temperature |
| Acceptable Hours per Week | hours | 2 | Allowed hours with sensor deviation |
Output Calculated Trend Logs
| Output CTL | Units | Frequency | Description |
|---|---|---|---|
| SlowStartupDailyCount | daily | Number of times the slow start condition occurs in a day |