Determine if cooling tower bypass valve operation is faulty
Applicable Systems
Primary: CHLR
Objective/Method/Outcome
Objective: Determine whether the cooling tower bypass valve is operating properly.
Method: Bypass valve is considered faulty when it is fully open (100%) and the Cooling Tower Flow is above the minimum (100GPM).
Outcome: An insight is generated if this condition has occurred for more than 4 hours this week.
Logic
Normalize all inputs to 15-minute intervals. When the bypass valve is fully open (100%) and the flow is greater than the minimum, calculate “fault” time. Sum this over the week. Store in CTL. Trigger insight if the sum is over the threshold. Also, store Bypass Valve Position Hourly Average and Cooling Tower Flow Hourly Average.
sum hours over the week{
if (flow greater than minimum and bypass valve is on, time, 0)
}
if(sum> threshold , Insight, no_insight)
Determine if cooling tower bypass valve operation is faulty
Notes
The rule generates two Calculated Trend Logs (Bypass Valve Position Hourly Average, and Cooling Tower Flow Hourly Average).
Inputs
Inputs
Units
Tags
Description
CHWS Enable
0/1
enable
cmd,cool,water,system
Equipment On/Off Indicator
Flow
GPM
tower,flow,sensor
Cooling Tower Flow
Bypass valve Position
%
bypass,valve,cmd
feedback
Bypass Valve
Parameters
Inputs
Units
Default Value
Description
Weekly Threshold
hours
4
Allowable time for bypass valve to be open and cooling tower flow greater than minimum
