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

Objective/ Method/Outcome

Objective: Determines if the chiller condenser water supply temperature (CWST) has deviated too far from the common CWST.

Method: Compares the CWST and common CWST 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 deviation between the active chiller condenser water supply temperature and the common condenser water supply temperature is too high. This rule is part of the CopperTree Standard rule-set.

Default Priority

Low

Diagnosis

A condenser water supply temperature sensor is out of calibration

Message

Deviation between the active chiller CWST and the common CWST 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