Applicable Systems
- Primary: CHLR
Description / Method
Calculates the number of hours in a day when the cooling tower fan is ON while the bypass valve is open. Generates an insight if the number of hours exceeds 1 hour/day. {CHLR|chiller}.
Logic
Normalize all inputs to 5-minute intervals. When the cooling fan is on and the bypass valve is open, calculate time. Sum this over the day. Store in CTL. Trigger insight if the sum is over the threshold.
sum over the day{
if (cooling fan is on and bypass valve is on, time, 0)
}
if(sum> threshold , Insight, no_insight)
Diagnosis / Recommended Action
- Cooling tower fan might be in hand (no longer controlled by the program).
- Review cooling tower fan control and sequence.
Message
Cooling tower fan has been ON for more than 1 hour for the day while the bypass valve is open
Notes
All timespans and thresholds are adjustable. Generates CTL named “Daily Hours Cooling Tower ON Bypass Valve Open “Default Inputs:
- Daily Threshold [Hours] = 1
Rule Template Type
- Insight Type: Fault Detection
- Trigger Type: Active High
Default Priority
Medium
Inputs
| Inputs | Units | Tags | Description |
|---|---|---|---|
| Cooling Tower Fan Status | 0/1 | status,tower,fan,chiller | Equipment On/Off Indicator |
| Bypass Valve (OFF/ON) | 0/1 | valve,bypass,ctrl|status,chiller | Bypass valve status |
Constants
| Inputs | Units | Default Value | Description |
|---|---|---|---|
| Daily Threshold | hours | 1 | Allowable time for bypass valve to be open and cooling tower fan to be running |
Output Calculated Trend Logs
| Output CTL | Units | Frequency | Description |
|---|---|---|---|
| Daily Hours Cooling Tower ON with Bypass Valve Open | hours | daily | Total hours that fan runs with valve open |
