EAD is open when AHU is disabled

Objective/ Method/Outcome

Objective: Determines if the Exhaust Air Damper is open while the AHU Exhaust Fan is inactive.

Method: Compares the Exhaust Air Damper to the Exhaust Fan Status. If the Exhaust Air Damper is open while the Exhaust Fan Status signal is inactive, the hours of faulty operation are calculated.

Outcome: This rule generates an insight if the Weekly Hours of Faulty Operation exceeds the acceptable weekly threshold.

Description

Reference: ASHRAE36-5.16.4/5/6

This rule determines if exhaust air damper is closed when AHU is not operating. The consequence would be humidity building up in the duct work.

This rule is part of the CopperTree Standard rule-set. (Aliased Celsius / Aliased Fahrenheit)

Default Priority

Medium

Diagnosis

1. Inspect the equipment to see if it has been overridden manually.

2. Review control sequence.

Message

EAD is open when AHU is disabled

Rule Template

Insight Type: Fault Detection

Trigger Type: Active High

Notes

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

Default Values:

Const. – Threshold – Weekly Hours of Faulty Operation [Hrs]: 4

CTLs:

EAD Open, Fan Inactive – Weekly Hours of Faulty Operation (KPI)

EAD Open, Fan Inactive – Hours of Faulty Operation (CUSUM)