Applicable Systems
- Primary: AHU, RTU, MUA, ERV, BLR, CHLR
- Secondary: HP, FCU, UV, UH
Description / Method
Analyzes equipment state changes using Analog or Binary trend log. Insight is triggered when Property Impact exceeds the weekly threshold (defined by user). This can be changed to trigger on Urgency Score.{BLR,CHLR,AHU,RTU,UV} Generates Daily_Status_Changes as CTL.
- Property Impact is calculated as the number of days during the week where the cycle count was higher than the threshold (expresses in percent of total days being monitored in the week)
- Also calculates Urgency Score 0 to 100 based on the cycle count.
Logic
Diagnosis / Recommended Action
Check and revise programming and sequence of operation to prevent unnecessary equipment cycling.
Message
Equipment state changes are higher than expected. Check and revise programming and sequence of operation to prevent unnecessary equipment cycling.
Notes
Could be applied to Boiler, Chiller, Compressor, Pump, AHU, FC, AC, Cooling/Heating stage.
Urgency Score is a measure of how urgent the fault is and a high score denotes critical adverse impact on the equipment. Urgency Score is scaled so that if the number of cycles is equal to or less than the Daily Cycles Threshold, the score is 0. If the number of cycles per day is twice that of the Daily Cycles Threshold, the score is 100. The maximum score of the week is used to trigger the Insight.
Default values for constants:
- Threshold – Amperage Status [A]: 1
- Number Of Days Monitored Per Week: 7
- Threshold – PropertyImpact Weekly: 14
- Threshold – UrgencyScore WeeklyMax: 50
- Threshold – Daily Cycles: 20
Rule Template Type
- Insight Type: Fault Detection
- Trigger Type: Active High
Inputs
| Inputs | Units | Default Value | Tags | Description |
|---|---|---|---|---|
| Equip Command Or Amperage {sensor,status} | Amps | sensor,status | Amperage or command status of equipment you would like to monitor. | |
| Threshold – Amperage Status [A] | Amps | 1 | Minimum current before equipment is considered to be on | |
| Threshold – PropertyImpact Weekly | Days | 14 | Weekly threshold to trigger a Property Impact Insight | |
| Threshold – UrgencyScore WeeklyMax | 50 | Weekly threshold of Urgency Score to trigger an Insight | ||
| Threshold – Daily Cycles | 20 | Number of equipment cycles per day before it is considered to be cycling too frequently |
Output Calculated Trend Logs
| Output CTL | Units | Description |
|---|---|---|
| Daily_Status_Changes | Cycles/Day | Status Changes per day |
| PropertyImpact_Weekly | % | Weekly Property Impact |
| UrgencyScore_WeeklyMax | Weekly Urgency Score |
