Hot Water System – Staging Sequence Between Boilers and Primary Pumps is incorrect

Objective/ Method/Outcome

Objective: Determines if a sequencing error exists between boilers and primary pumps.

Method: Compares the total number of primary pumps operating to the total number of boilers operating for up to 3 primary pumps and 3 boilers. An insight is generated when a mismatch occurs for greater than the defined daily threshold. Avoidable Cost and Potential Savings are determined by calculating unnecessary pump energy consumption.

Outcome: This rule generates an insight.

Description

Reference: ASHRAE Guideline 36-5.21.6.10 This rule determines if the number of operating pumps matches the number of running boilers. This rule is applicable for a group of boilers and associated pumps. This rule is part of the CopperTree Standard rule-set.

Default Priority

High

Diagnosis

1. Check whether the pumps and boilers are running in auto or manual mode.

2. Inspect the MCC panel of the concerned pumps and the starter panel of the boilers.

3. Ensure the relay panels within the concerned DDC are functioning properly.

Message

Incorrect staging sequence between boilers and primary pumps. Review and modify the sequence of operations.

Rule Template

Insight Type: Fault Detection

Trigger Type: Active High

Inputs

Input	Unit	Tags	Description
Primary Hot Water Pump 1-3 Status		Hot Water Pump Status, Hot Water Pump Command
Boiler 1-3 Status		Boiler Status, Boiler Command
Threshold – Daily Hours of Faulty Operation	Hours		The minimum hours of fault that can trigger an insight
Pump Power Rating	HP		The manufacturer defined rating
Pump Energy Rate	$/kWh		The cost of pump operation per kWh
Weeks of Operation			The annual weeks of operation

Notes

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

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

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

Default Values:

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

Const. – Pump Rating [HP]: 10

Const. – Electricity Rate [$/kWh]: 0.1 Const. – Weeks of Operation: 26