Hot/Chilled Water System – Water flow is too high with the associated pumps off

Objective/ Method/Outcome

Objective: Determines if the hydronic loop flow is too high when all associated pumps are inactive.

Method: Compares the hydronic flow to the defined flow threshold and determines a fault when the threshold is exceeded while the associated pump status signals are inactive. An insight is generated when this occurs for greater than the defined daily threshold.

Outcome: This rule generates an insight.

Description

Reference: ASHRAE Guideline 36-5.21.11.6/ASHRAE Guideline 36-5.20.18.6 This rule determines if loop flow is a reasonable value when associated pumps are off. This rule is part of the CopperTree Standard rule-set.

Default Priority

Low

Diagnosis

Verify flow meter operation.

Message

Water flow is too high with the associated pumps off.

Rule Template

Insight Type: Fault Detection

Trigger Type: Active High

Inputs

Input	Unit	Tags	Description
Associated Pump 1-4 Status		Chilled Water Pump Status, Hot Water Pump Status
Flow	LPS, GPM	Chilled Water Supply LPS, Hot Water Supply LPS, Chilled Water Supply GPM, Hot Water Supply GPM
Acceptable Time Outside Range per Day	Hours		The minimum hours of fault that can trigger an insight
Minimum Flow Threshold	GPM		The defined threshold to determine faulty operation

Notes

1. Only one “Flowrate”, [LPS] or [GPM] is needed.

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

3. The input(s) that is(are) not used should be set to “0”.

Default Values:

Const. – Acceptable Time Outside Range per Day [hours]: 2

Const. – Minimum Flow Threshold [GPM]: 20