Applicable Systems
- Primary: AHU, RTU, MUA, ERV, BLR, CHLR
- Secondary: VAV, HP, FCU, UV, UH
Objective/Method/Outcome
- Objective: Determine if the Final Control Element (SF, RF, EF, HCP, CCP, DX) controlled by an on/off signal is changing status at a very high rate.
- Method: Check the number of times the Final Control Element has cycled on/off over the course of a day.
- Outcome: An insight is generated if the number of status changes is more than 12 cycles per day.
Logic
Sum daily(numberOfStatusChanges)
Inputs
- Occ ( Binary Trend Log)
- The occupancy trendlog should be COV, to get the greatest value for this rule.
- FCE {cmd, valve|damper|vfd}
Notes
Input should be binary, preferably with a COV trend log. The secondary equipment short cycling rule allows for more status changes per day than the primary equipment short cycling rule.
Parameters
| Parameter | Expression Block Series Number | Description | Default Value (Units) |
|---|---|---|---|
| Max Cycles per Day | 7 | The acceptable number of unit status changes. Anything more than that time is considered a fault. | 18 (Cycles per day) |
