Chilled Water System – Chiller status and isolation valve position are mismatched

Objective/ Method/Outcome

Objective: Determines if the chiller status and isolation valve status signals are matching.

Method: Compares the chiller status and isolation valve status signals to check if their activity matches and generates an insight when a mismatch occurs for greater than the defined daily threshold. Avoidable Cost and Potential savings are determined based on an hourly cost of faulty operation.

Outcome: This rule generates an insight.

Description

This rule determines if isolation valve operation is synchronized with chiller status. This rule is part of the CopperTree Standard rule-set.

Default Priority

High

Diagnosis

1. Check if the equipment is manually overridden.

2. Check interfacing relays.

3. Check status sensors.

Message

Chiller status and isolation valve position are mismatched. Please investigate chilled water system.

Rule Template

Insight Type: Fault Detection

Trigger Type: Active High

Inputs

Input	Unit	Tags	Description
Chiller Status		Chiller Status, Chiller Command
Isolation Valve Status		Valve Command, Valve Status
Threshold – Daily Hours of Faulty Operation	Hours		The minimum hours of fault that can trigger an insight
Weeks of Operation			The annual weeks of operation
Cost per Hour	$		The defined hourly cost of faulty operation

Notes

1. Expected values for “Chiller Status” inputs are “0” or “1”.

2. Expected values for “Isolation Valve Status” inputs are “0” or “1”.

Default Values:

Const. – Threshold – Daily Hours of Faulty Operation [Hours]: 2

Const. – Cost per Hour [$]: 0 Const. – Weeks of Operation: 26