Determine if chiller is operating when OAT is below chiller enable set point
Applicable Systems
- Primary: CHLR
Objective/Method/Outcome
- Objective: Determine if the chiller is operating when cooling may not be required.
- Method: Check if chiller is running when outdoor air temperature (OAT) is greater than user defined threshold.
- Outcome: An insight is generated when the chiller is ON for more hours per week than the allowed threshold
Logic
The logic flow starts by normalizing all the inputs to 5 min intervals. Block(26) determines if the chiller is on. Block(7) determines if the outdoor temp is below threshold If both (26) and (7) are true then sum the time per day and record this in CTL. Sum the times both (26) and (7) are on per week and compare this to the threshold
while(chiller = On and OAT < threshold) {
CTL = agg (daily) with # of hours
if agg (weekly) > threshold then generate insight
}
Determine if chiller is operating when OAT is below chiller enable set point
Description / Method
Determine if the chiller is operating when a heating plant may not be required. {BLR} Check if the chiller is enabled below the desired OAT threshold.
Diagnosis / Recommended Action
- Verify heating plant sequence of operation.
- Enable Automatic control.
Message
The chiller has been operating for more than 4 hours a week while the OAT is below its enable set point of 30 degrees. Verify heating plant sequence of operation.
Notes
Rule Template Type
- Insight Type: Fault Detection
- Trigger Type: Low
Default Priority
Medium
Inputs
| Inputs | Units | Tags | Description |
|---|---|---|---|
| Chiller Status | 0/1 or Amps | blr, status | Chiller status |
| Chiller ON Threshold | 0/1 or Amps | Threshold that indicates chiller is on | |
| OAT | °C/°F | sensor, outside, air, temp | Outdoor air temperature |
Constants
| Constant | Units | Default Value | Description |
|---|---|---|---|
| Minimum OAT Threshold [deg] | °C/°F | 14 | Outdoor temperature threshold for chiller operation |
| Weekly Acceptable Hours | hours | 4 | Number of hours chiller is allowed to run when temp is below OAT |
Output Calculated Trend Logs
| Output CTL | Units | Frequency | Description |
|---|---|---|---|
| Daily hours chiller operating below OAT threshold | hours | daily | Hours per day that chiller is operating below temp threshold |