Room Automation Station Fault Detection and Diagnostics Configuration for DXR A6V12035398 2020-06-04 Smart Infrastructure
Table of Contents Before You Begin ............................................................................................................. 5 Fault Detection and Diagnostics Configuration for DXR .............................................. 6 Scope and Purpose............................................................................................................ 6 DXR Template Feature Selections .....................................................................................
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Before You Begin Before You Begin Knowledge and Training Prerequisites The reader / user of this document must be trained, knowledgeable, and familiar with using ABT Site to configure DXR automation stations. See appendix for California Title 24 detailed information.
Scope and Purpose Fault Detection and Diagnostics Configuration for DXR Scope and Purpose This document provides the automation engineer and specialist/technician instructions for the following: How to configure a DXR automation station variable air volume or fan-powered box template to meet fault detection & diagnostic requirements for the energy standards specified in California Title 24 – Part 6 (CA T24-2019).
DXR Template Feature Selections DXR Template Feature Selections The following feature selections will enable fault detection and diagnostics (FDD) capability in HvacLgtShd12 (VAV) and HvacLgtShd13 (FPB) application templates. When enabled, FDD functions run continuously in the DXR. Prerequisite • The VAV or FPB template to be customized is loaded and accessible in ABT Site. (See screen captures below.) FDD Template Selections Only FDD-required feature selections are provided in this document.
DXR Template Feature Selections Step 4 – HVAC Configuration Confirm / Set HVAC to Active. For HVAC configuration, select functions for Supply air VAV, Extract air VAV, and Heating coil (see figure). Step 5 – Room Segment (Auxiliary functions) Hvac FDD can now be set to Active. Up to four fault types can be selected. Select Active to enable each that is required to meet your job specifications.
DXR Template Feature Selections Note, only those faults that are supported by the DXR configuration can be activated. For example, the figure below shows that the Dual duct flow fault is not available (“Active” is greyed out). Monitor fault options, if supported by the DXR configuration, can be activated.
DXR Template Feature Selections If the fault needs to be monitored using an Event Enrollment Object (monitored as an alarm), select Activate for each corresponding “Monitor” fault. Step 6 – Room (HVAC coordination) To support Dual Max Heat, the following selections are critical: • VAV terminal units with reheat: you must select VAV temp.cascade heating 11 • FPB terminal units with reheat: you must select FPB temp.
Step 7 – Default values Step 7 – Default values To configure a DXR to meet Title 24 requirements, the following features must be configured as necessary: • Heating coil • Ventilation control • Supply air VAV • Extract air VAV Heating coil To support dual maximum VAV control (“Dual Max”), the following changes must be made to the heating coil default values. 1) Set the Max.supply air temp.setpoint for heating to be 95°F or lower. 2) Ensure that the Min.supply air temp.
Step 7 – Default values (Note that there may be other acceptable configurations that may use proportional and integral control.) Step 4: Determine the control range for CO2 ppm. (In an ideal DCV implementation the control range will be an impulse. In this example, control range = 100 ppm.) Step 5: Calculate the Gain on the ventilation PID controller object. Formula: Gain = 100% / control range Step 6: Calculate the “Setpoint room air quality for comfort” and the “Setp.room.air quality for pre-comfort”.
Step 7 – Default values Supply air VAV If the area being served by the DXR is required to provide Demand Control Ventilation (DCV), then the following Supply Air VAV default values MUST be modified. Step 1: Check the Supply air VAV max.air vol.flow f.vent for “Avail. on AS”. The value for DCV should be based on the maximum ventilation airflow rate of 15 CFM/person x number of people in room (e.g., 12 people x 15 CFM/person =180 CFM). Step 2: Make sure Supply air VAV min. air vol.flow f.
Step 8 – Fault detection and diagnostics parameters Step 8 – Fault detection and diagnostics parameters This step covers the addition and configuration of paramaters for: • Supply flow fault and diagnostics • Supply heat temp fault and diagnostics • Extract flow fault and diagnostics • Dual Duct flow fault and diagnostics To add additional parameters to the Default values, left click on the upper right of the Configuration Tab screen.
Step 8 – Fault detection and diagnostics parameters Supply VAV air flow fault diagnostics Configuration: Descriptor Object Type Default Value Supply VAV air flow fault MCalcVal Normal Supply VAV unstable control fault BCalcVal Supply VAV unstable control reset MTrgVal Ready Supply VAV airflow fault tolerance ACnfVal 100 (170) (47) Ft3/min (m3/hr) (lps) (SuAflFltTol) ACnfVal 600 s (SuAflFltDly) ACnfVal 2 % (SuPosTol) ACnfVal 5 ACnfVal 600 Difference between measured airflow and
Step 8 – Fault detection and diagnostics parameters Click on Reset to reset VAV unstable control fault. Can also be reset from Insight, reset object will automatically return to ready when done from Insight.
Step 8 – Fault detection and diagnostics parameters Supply VAV air flow fault determination AND IF AHU MODE = ON AHU MODE = OFF 1) 2) THEN Supply air flow < Supply air flow Setpoint minus flow tolerance Supply air flow > Supply air flow Setpoint plus flow tolerance conditions exists for greater than flow fault delay Number of unstable positions exceed change limit within the change time (2) Supply air flow FAULT Supply air flow unstable FAULT (1) NO - - - Normal Normal YES - YES - Lo F
Step 8 – Fault detection and diagnostics parameters Supply heat temp fault and diagnostics Configuration: Descriptor Object Type Default Value Units Enumeration Abbreviated Name Supply air heating temperature fault MCalcVal Normal Primary air temperature ACalcVal 32 °F PRI AIR TMP (TPa) Supply temp heating controller for heating coil. ACalcVal 0 % HclTSuCtrH Supply air heating temperature tolerance ACnfVal 9 (5. K) °F HtSuFltTol ACnfVal 600 s HTSuFltDly ACnfVal 100 (4.
Step 8 – Fault detection and diagnostics parameters On-line 19 Unrestricted A6V12035398
Step 8 – Fault detection and diagnostics parameters Aux Function for Supply temperature fault (with Dual Duct supply air configured) o Note: Supply air temperature setpoint (HTSuSp) not displayed in this view A6V12035398 Unrestricted 20
Step 8 – Fault detection and diagnostics parameters Supply heat temp fault determination AND THEN Supply air Temperature < Supply air Setpoint minus temp threshold Supply air temperature > Max (Supply air Setpoint, Primary air Temp) plus temp threshold conditions exists for greater than fault delay AHU MODE = ON and Supply Air flow setpoint > flow threshold NO - - Normal YES - YES Lo Temp - NO - Normal - YES YES Hi Temp AHU MODE = OFF or Supply Air flow setpoint < flow threshold - -
Step 8 – Fault detection and diagnostics parameters Extract flow fault and diagnostics Configuration: Descriptor Object Type Default Value Extract VAV air flow fault MCalcVal Normal Extract VAV unstable control fault BCalcVal Extract VAV unstable control reset MTrgVal Ready Extract VAV airflow fault tolerance ACnfVal 100 (170) (47) Ft3/min (m3/hr) (lps) (ExAflFltTol) ACnfVal 600 s (ExAflFltDly) ACnfVal 2 % (ExPosTol) ACnfVal 5 ACnfVal 600 Difference between measured airflow and
Step 8 – Fault detection and diagnostics parameters 23 Unrestricted A6V12035398
Step 8 – Fault detection and diagnostics parameters Extract VAV fault determination AND IF AHU MODE = ON AHU MODE = OFF 1) 2) THEN Extract air flow < Extract air flow Setpoint minus flow tolerance Extract air flow > Extract air flow Setpoint plus flow tolerance conditions exists for greater than flow fault delay Number of unstable positions exceed change limit within the change time (2) Extract air flow FAULT Extract air flow unstable FAULT (1) NO - - - Normal Normal YES - YES - Lo Flo
Step 8 – Fault detection and diagnostics parameters Dual Duct flow fault and diagnostics Configuration Duct 1 and Duct 2: Descriptor Object Type Default Value Supply air flow fault 1 MCalcVal Normal 1: Normal 2: Hi Flow 3: Low Flow SU1FLOW FLT (Su1AirFlFlt) Supply air flow fault 2 MCalcVal Normal 1: Normal 2: Hi Flow 3: Low Flow SU2FLOW FLT (Su2AirFlFlt) Supply unstable control fault 1t BCalcVal Normal, Fault SU1UNSTB FLT (ExUnstblCtlFlt) Supply unstable control fault 2t BCalcVal Normal,
Step 8 – Fault detection and diagnostics parameters Supply position change time limit 1 ACnfVal 600 s (SuPosChgTiLim1) ACnfVal 600 s (SuPosChgTiLim2) The oscillation counter will be reset, if the position tolerance has not been exceeded for this length of time. Supply position change time limit 2 The oscillation counter will be reset, if the position tolerance has not been exceeded for this length of time.
Step 8 – Fault detection and diagnostics parameters Dual Duct VAV fault determination Duct 1 and Duct 2 have separate faults and configurations. Dual duct configurations can be set to specify which duct is for cooling or heating temperature control.
Step 8 – Fault detection and diagnostics parameters o A6V12035398 Each unstable fault point will remain at Fault until the user/operator commands the Supply unstable control reset 1 (2) from ‘Ready’ to ‘Reset’. This will clear the unstable fault and return the Unstable control reset back to ‘Ready’.
Step 9 – Fault suppression Step 9 – Fault suppression Condition of AHU Mode SplyAir11 – Central application function Fault Detection and Diagnostics for DXR is designed to work with SplyAir11 Central application function (“Supply chain air 11, for central air handling unit (AHU)”).
Step 9 – Fault suppression Primary air temperature For the Supply heating temp FDD to work properly, a SplyAir Central function must be configured and present. Otherwise, the primary air temperature will always be 32°F (0°C) in the Supply heating temp FDD. When a SplyAir Central function is defined, the Primary air temperature will be set equal to AHU Supply air temperature. NOTE: Optional DXR input “Primary air temp for after air treatment” is not used for this FDD point.
For the Tester For the Tester NRCA-MCH13A (Revised 6/17) section C (Functional Testing for Zone Terminal Units) contains 7 steps/tests which can result in 3 possible BACnet Point alarm/fault. Please note that steps 1-6 result in a fault being reported via one of the 3 possible BACnet Point faults. Step 7 tests functionality and will not result in a fault alarm.
For the Tester needed. Low flow fault will be detected if the Supply air flow is less than the Supply air flow setpoint by the configured flow tolerance. SU FLOW FLT will be set to Low Flow. Test 4: Heating valve actuator To test the SU H TMP FLT, the terminal box should initially be in neutral zone. If necessary, command RM TEMP SHFT such that the terminal box is not in heating. Disconnect the heating output by removing power to the valve actuator.
Fault detection & diagnostic (FDD) alarms Appendix The appendix has detailed background information on Title 24 and additional information regarding Demand Control Ventilation. Fault detection & diagnostic (FDD) alarms See 2019 nonresidential Compliance Manual section 13.16 NA7.5.12 for acceptance criteria and NRCA-MCH13-A for acceptance test form.
California Title 24 zone level requirements California Title 24 zone level requirements 2019 CA Title 24 has four zone level requirements that are met by a DXR with proper configuration connected to Insight 3.14/3.15 or Desigo CC. These requirements include: • • • • Dual Maximum Heating (PRESCRIPTIVE) o §140.4(d) Automatic Demand Shed Control (MANDATORY) o §110.12(b) o §120.2(h) o §120.5(a)10 Demand Control Ventilation (MANDATORY) o §120.1(c)3 o §120.1(c)4 o §120.1(d) o §120.1(f) o §120.
California Title 24 zone level requirements To see which of the three remaining possible requirements are required for your project, you must look at the Title 24 requirements chart typically in the early sheets of the Mechanical set. The EOR (engineer of record) must include several Title 24 documents in the Mechanical sets, including NRCC-MCH-01E which contains the Mechanical HVAC Acceptance Tests & Forms table. A sample table is included below.
Dual Maximum VAV Control Dual Maximum VAV Control Title 24 requires the DDC application to support Dual Maximum VAV control for Vav/Fpb terminal units with reheat (modulating hot water or electric). See 2019 nonresidential Compliance Manual section 4.5.2.1 for more information. In summary, for systems with DDC at the zone level, the controls must be able to support two different CFM maximums, one each for heating and cooling. In cooling, this control scheme is like a traditional VAV reheat box control.
Automatic Demand Shed Automatic Demand Shed See 2019 nonresidential Compliance Manual section 4.5.1.6 for more information, section 13.14 NA7.5.10 for acceptance criteria and NRCA-MCH11-A for acceptance test form. In summary, if this acceptance form is required (box checked on the Title 24 sheet), all controls systems with DDC to the zone level are required to enable centralized demand shed at non-critical control zones from either a single software or hardware point in the system. §120.
Demand Control Ventilation Demand Control Ventilation See 2019 nonresidential Compliance Manual section 4.3.7 for more information, section 13.9 NA7.5.5 for acceptance criteria and NRCA-MCH-06-A for acceptance test form. Note: If this acceptance form is required (box checked on the Title 24 sheet), control systems with DDC to the zone level are required to enable centralized demand shed at non-critical control zones from either a single software or hardware point in the system.
Demand Control Ventilation Issued by Siemens Industry, Inc. Smart Infrastructure 1000 Deerfield Pkwy Buffalo Grove IL 60089 +1 847-215-1000 A6V12035398 (AA) © Siemens Industry, Inc., 2020 Technical specifications and availability subject to change without notice.
