Chilled Water System – Deviation between the active chiller CHWRT and the common CHWRT is too high

Objective/ Method/Outcome

Objective: Determines if the chilled water return temperature (CHWRT) has deviated too far from the common CHWRT.

Method: Compares the CHWRT and common CHWRT to the defined error threshold and generates an insight when this fault occurs for greater than the defined daily threshold.

Outcome: This rule generates an insight.

Description

Reference: ASHRAE Guideline 36-5.20.18.6 This rule determines if the deviation between the active chiller chilled water return temperature and the common chilled water return temperature is too high. This rule is part of the CopperTree Standard rule-set.

Default Priority

Low

Diagnosis

A chilled water return temperature sensor is out of calibration

Message

Deviation between the active chiller CHWRT and the common CHWRT is too high.

Rule Template

Insight Type: Fault Detection

Trigger Type: Active High

Notes

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

Default Values:

Const. – Temperature error threshold for chilled water temperature sensors [°C]: 1°C

Const. – Daily Faulty Hours Threshold [hours]: 2 hours