Chiller System BMS

CBP @ Plot 61 Honeywell

Project: CBP @ Plot 61Document: Chiller FDSDate: 25-June-2012Rev: 3

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DESIGN DOCUMENTATIONFUNCTIONAL DESCRIPTION

FORChiller System

OFFICE

25th June 2012



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Revision History

Rev Date Description Prepared Checked Approved0 26th May 2012 Initial Release Andrew Turley S. Mahandra Lay Lwin1 6th June 2012 Revised as per comments Andrew Turley S. Mahandra Lay Lwin2 20th June 2012 Revised as per comments Loon YS S. Mahandra Lay Lwin3 25th June 2012 Revised as per comments Loon YS S. Mahandra Lay Lwin



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Table of Contents1.1 System Description .............................................................................41.2 Flow Chart...........................................................................................6

1.2.1 Chiller Set Enable....................................................................................... 61.2.2 Chiller Staging Control ..............................................................................7

1.3 Chiller Set Sequencing Control .........................................................81.2.3 CH-BP-1, CH-BP-2 & CH-BP-3 Sequencing Control............................... 81.2.4 CH-BP-4 & CH-BP-5 Sequencing Control................................................81.2.5 Chiller Set Fault Monitoring and Lockout ...............................................101.2.6 Chilled and Condenser Water Pumps Failure ..........................................11

1.4 Cooling Tower Sequence Control....................................................121.4.1 CT-BP-01, CT-BP-02 & CT-BP-03......................................................... 121.4.2 CT-BP-04 & CT-BP-05 ...........................................................................121.4.3 Cooling Tower Lock Out Mode ........................................................... 13

1.5 Monitoring of Auto / Manual Control Switches ............................151.6 System Maintenance Mode ..............................................................151.7 Chiller Set Staging Control ..............................................................16

1.7.1 General Overview ....................................................................................161.7.2 Chiller Start-Up and Shut-Down Sequence .............................................171.7.3 Staging On of Lag Chiller Sets ......................................................... 181.7.4 Staging Off of Lag Chiller Sets......................................................... 181.7.5 Staging Table............................................................................................ 191.7.6 Calculation of Building Load...................................................................20

1.8 Chilled Water Pump VSD control...................................................221.9 Chilled Water Bypass Valve Control ..............................................251.10 Condenser Water Pump VSD control.............................................261.11 Cooling Tower System Control .......................................................28

1.11.1 Cooling Tower Fan VSD Control ............................................................ 291.12 System Energy Monitoring ..............................................................311.13 Heat Balance Calculation and Monitoring .....................................321.14 Hardware Point Summary...............................................................361.15 High Level Point Summary..............................................................391.16 Chilled Water Schematic..................................................................42



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1.1 System Description

The chilled water system is located in the chiller plant room on level 9 of the buildingand consists of six chillers operating in a parallel arrangement on the supply side ofthe primary supply and return headers. The total duty load of all Duty and Lag chillersis set at 3440 Ton.

Three Trane chillers with a capacity of 1030 Ton (Duty/Lag/Lag) Two chillers with a capacity of 515 Ton (Duty/Standby) One chiller with a capacity of 350 Ton (Duty)

The chillers are staged in order to meet the system efficiency requirements based on apercentage of the total duty load of 3440 Ton (3 x 1030 Ton + 350 Ton):

8.33% to 20% = 0.65 kW/Ton 20% to 100% = 0.6 kW/Ton

The chillers are staged On and Off by means of the Honeywell Direct DigitalControl system by controlling the set refrigeration compressor Enable interlocksignal. The individual chiller sets load and unload as required under their own integralpackage control system.

Chiller Type Capacity(Ton)Capacity(KWR)

EvaporatorFlow Rate

(L/S)

CondenserFlow Rate

(L/S)CH-BP-01 Trane 1,030 3,514 123.28 204CH-BP-02 Trane 1,030 3,514 123.28 204CH-BP-03 Trane 1,030 3,514 123.28 204CH-BP-07 Trane 350 3,514 41.9 74.6CH-BP-04 Trane 515 3,514 61.64 102CH-BP-05 Trane 515 3,514 61.64 102

The Chillers are served by 6 variable speed chilled water pumps that operate in aparallel arrangement and are connected to the supply side of the primary supply andreturn headers. The chilled water pumps are dedicated to chillers as detailed in thebelow table under the associated chiller column.

Pump Associated Chiller Power (Kw) Flow (L/S)

CHWP-BP-01 CH-BP-01 37 123.28CHWP-BP-02 CH-BP-02 37 123.28CHWP-BP-03 CH-BP-03 37 123.28CHWP-BP-07 CH-BP-07 15 41.9CHWP-BP-04 CH-BP-04 18.5 61.64CHWP-BP-05 CH-BP-05 18.5 61.64



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The Chillers are served by 6 variable speed condenser water pumps that operate in aparallel arrangement and are connected to the supply side of the primary supply andreturn headers. The condenser water pumps are dedicated to chillers as detailed in thebelow table under the associated chiller column.

Pump Associated Chiller Power (Kw) Flow (L/S)

CNWP-BP-01 CH-BP-01 55 204CNWP-BP-02 CH-BP-02 55 204CNWP-BP-03 CH-BP-03 55 204CNWP-BP-07 CH-BP-07 22 74.6CNWP-BP-05 CH-BP-04 30 102CNWP-BP-06 CH-BP-05 30 102

The cooling tower system for the complex consists of five multi cell cooling towerswith each cell fitted with a variable speed fan. The cooling towers are located in theRoof level plant room area and are connected in a parallel arrangement. The coolingtowers are sized as detailed in the below table. Similar sized towers are not dedicatedto any particular chiller and are sequenced separately depending on the system loadand enabled chillers.

CT Comment Fan Power(Kw) Flow (L/S)

CT-BP-01 7 Fan Cells CT-1-1~7 (1030 RT) 5 kW X 7 204CT-BP-02 7 Fan Cells CT-2-1~7 (1030 RT) 5 kW X 7 204CT-BP-03 7 Fan Cells CT-3-1~7 (1030 RT) 5 kW X 7 204CT-BP-07 3 Fan Cells CT-7-1~3 (350 RT) 5 kW X 3 74.6CT-BP-04 4 Fan Cells CT-4-1~4 (515 RT) 5 kW X 4 102CT-BP-05 4 Fan Cells CT-5-1~4 (515 RT) 5 kW X 4 102

Sensors are installed in the primary chilled and condenser water flow and return linesin the following piping:

a) Common Chilled Water Supply and Return Temperatureb) Common Condenser Water Supply and Return Temperaturec) Individual Chiller Evaporator Inlet and Outlet Temperature (6)d) Individual Chiller Condenser Inlet and Outlet Temperature (6)e) Individual Chiller Chilled Water Flow Rate (6)f) Individual Chiller Condenser Water Flow Rate (6)g) Individual Chiller Evaporator Pressure (6)h) Individual Chiller Condenser side Pressure (6)

Refer to Hardware Point List section for full details of all input / output points.



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1.2 Flow Chart1.2.1 Chiller Set Enable



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1.2.2 Chiller Staging Control



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1.3 Chiller Set Sequencing Control

1.2.3 CH-BP-1, CH-BP-2 & CH-BP-3 Sequencing Control

The sequence of the three chiller sets CH-BP-1, CH-BP-2 and CH-BP-3 is initiallyrotated on a weekly basis at 4:30 am (user adjustable) every Sunday depending on theactual run hours of each set. The time, day and frequency of the sequence reset arefully adjustable. The frequency can be adjusted to a daily, weekly or monthly reset.

The operating status of each chiller set compressor motor is monitored by theHoneywell DDC control system and the actual run hours of each set is accumulatedwithin the controller software and is displayed on the chilled water system graphic.

The chiller set with the lowest accumulated number of run hours is positioned as theLead set in the control sequence for that week and the set with the next highestnumber of run hours is positioned as the 1st Lag.

The set with the greatest number of run hours is then positioned as 2nd Lag in thecontrol sequence.

The sequence of the chiller sets will be arranged as detailed in the following table.

Lead Unit 1St Lag Unit 2nd Lag UnitLowest Runtime 2nd Lowest Runtime Highest Runtime

1.2.4 CH-BP-4 & CH-BP-5 Sequencing Control

The sequence of the two chiller sets CH-BP-4 and CH-BP-5 is initially rotated on aweekly basis at 4:30 am (user adjustable) every Sunday depending on the actual runhours of each set. The time, day and frequency of the sequence reset are fullyadjustable. The frequency can be adjusted to a daily, weekly or monthly reset.

The operating status of each chiller set compressor motor is monitored by theHoneywell DDC control system and the actual run hours of each set is accumulatedwithin the controller software and is displayed on the chilled water system graphic.

The chiller set with the lowest accumulated number of run hours is positioned as theLead set in the control sequence for that week and the set with the highest numberof run hours is positioned as the Standby.



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The sequence of the chiller sets will be arranged as detailed in the following table.

Lead Unit Standby UnitLowest Runtime Highest Runtime

In addition, the two 515 RT chiller sets CH-BP-4 and CH-BP-5 also have thefollowing functions as described below.

Backup for chiller sets CH-BP-1, CH-BP-2 and CH-BP-3

The two 515 RT chiller sets CH-BP-4 and CH-BP-5 also acts as backup units for the1030 RT units of CH-BP-1 to 3. In the event of a failure or maintenance scenario ofany one of the 1030 RT chiller sets, CH-BP-4 and CH-BP-5 will be ready to backupany of the 3 1030 RT chiller sets.

Backup for chiller sets CH-BP-7 during Failure or Maintenance

The two 515 RT chiller sets CH-BP-4 and CH-BP-5 also acts as backup units for the350 RT unit CH-BP-7. I

In the event of a failure or maintenance scenario of the 350 RT CH-BP-7 chiller set,CH-BP-4 and CH-BP-5 will act as backup and the Lead set will take over to replaceCH-BP-7.

Backup for chiller sets CH-BP-7 during Normal Operation

Similarly, during normal operation of the 350 RT CH-BP-7 chiller set (without anyfailure or maintenance), when the calculated base load exceeds that of the 350 RTchiller set, the Lead set of CH-BP-4 and CH-BP-5 will also cut in to meet therequired cooling load.

If the load only requires a 515 RT set (Lead set of CH-BP-4 and CH-BP-5) toreplace CH-BP-7 during this load demand condition, CH-BP-7 will cut out once theLead set of CH-BP-4 and CH-BP-5 cuts in so that only one unit of 515 RT chillerset is operating.



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1.2.5 Chiller Set Fault Monitoring and Lockout

1.1.5.1 Chiller Common Fault

The common fault for all chiller sets is monitored by the chiller system DDCcontroller by means of hard wired connections from the chiller set electrical controlpanel. An alarm condition is generated whenever a chiller common fault is active.

1.1.5.2 Chiller Fail to Start

Should a chiller set be Enabled to operate by the Honeywell DDC controller and thecorrect status input signal is not received at the controller within a time delay period of2 minutes (Adjustable) then a fail to start alarm will be generated.1.1.5.3 Chiller Shut off Valve Fail To Open

Shut off valves are installed in the supply lines of both the chilled water and condenserwater serving each chiller. The valves are controlled by the DDC and driven to theopen position whenever a chiller is enabled. Valve position status inputs are also wiredto the DDC controller. If any valve is enabled to open and the status input signal isnot received at the controller within a time delay period of 2 minutes (Adjustable) thena fail to open alarm will be generated.

1.1.5.4 Chiller Manual Off Condition

Individual Auto / Off / Manual switches are installed within the mechanicalelectrical switch board for the chiller.

An auxiliary voltage free contact associated with the Auto position of each switch isconnected as a digital input signal into the Honeywell DDC system and the contactsclose whenever the switch is in the Auto position.

If the switch is not in the auto position and the associated chiller is in the Off statefor a continuous period of 2 minutes (adjustable) then an alarm condition will begenerated.

1.1.5.5 Chiller Lockout and Reset

When a chiller set is in any of the Fault conditions detailed above then that set,along with its associated chilled and condenser water pumps, will be Locked Out ofthe chiller sequence and an alarm condition enunciated on the operators terminal ofthe Building Management System.



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The next available chiller set and associated chilled and condenser water pumps in thecontrol sequence will then be commanded On. Generally a failed chiller will bereplaced by a similar sized chiller if available. If no similar sized chiller is availablethen available chillers will be started according to load requirements.

Upon reset of the Fault condition at the chiller control panel or in the field thechiller system will remain Locked Out of the sequence until the Fault conditionhas been manually acknowledged, and reset by the operator or building engineer bymeans of a command signal on the relevant graphic display on the operators terminalof the Building Management System.

Once the Fault condition has been reset the chiller set will be returned to its originalposition in the staging sequence for that day.

1.2.6 Chilled and Condenser Water Pumps Failure

Should a chiller set chilled or condenser water pump be in any of the followingconditions then the associated chiller set chilled and condenser water pumps will beLocked Out of the chiller sequence and an alarm condition enunciated at theoperators terminal of the Building Management System:

1. Fail To Start (Start/Stop is ON and Status is OFF after pre-set internal timetolerance; Default = 30 sec (adjustable), (Reset Required)

2. Active Trip Alarm (Reset Required)3. Pump manual OFF condition (Mode= Remote and Status= OFF After preset

Internal Time tolerance; Default = 120 Sec (Adjustable)

The associated chiller set will then be controlled in an identical manner to that detailedin the Chiller Lockout and Reset section above.



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1.4 Cooling Tower Sequence Control

1.4.1 CT-BP-01, CT-BP-02 & CT-BP-03

The sequence of the three cooling towers sets CT-BP-01, CT-BP-02 & CT-BP-03 areinitially rotated on a weekly basis at 4:30 am (user adjustable) every Sundaydepending on the actual run hours of each set. The time, day and frequency of thesequence reset are fully adjustable. The frequency can be adjusted to a daily, weekly ormonthly reset.

The operating status of each cooling tower is monitored by the Honeywell DDCcontrol system and the actual run hours of each set is accumulated within thecontroller software and is displayed on the chilled water system graphic.

The cooling tower with the lowest accumulated number of run hours is positioned asthe Lead set in the control sequence for that week and the cooling tower with thenext highest number of run hours is positioned as the 1st Lag.

The cooling tower with the greatest number of run hours is then positioned as 2ndLag in the control sequence.

The sequence of the cooling towers will be arranged as detailed in the following table.

Lead Unit 1St Lag Unit 2nd Lag UnitLowest Runtime 2nd Lowest Runtime Highest Runtime

1.4.2 CT-BP-04 & CT-BP-05

The sequence of the two cooling towers CT-BP-04 & CT-BP-05 are initially rotatedon a weekly basis at 4:30 am (user adjustable) every Sunday depending on the actualrun hours of each set. The time, day and frequency of the sequence reset are fullyadjustable. The frequency can be adjusted to a daily, weekly or monthly reset.

The operating status of each cooling tower fan motor is monitored by the HoneywellDDC control system and the actual run hours of each set is accumulated within thecontroller software and is displayed on the chilled water system graphic.

The cooling tower with the lowest accumulated number of run hours is positioned asthe Lead set in the control sequence for that week and the set with the highestnumber of run hours is positioned as the Standby.



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The sequence of the cooling tower will be arranged as detailed in the following table.

Lead Unit Standby UnitLowest Runtime Highest Runtime

1.4.3 Cooling Tower Lock Out Mode

Assuming there are available towers, when any cooling tower has an adjustablenumber of fans (see table below) that are not available to run then that tower will beLocked Out of the sequence and an alarm condition annunciate on the operatorsterminal of the Control System. The following conditions will result in a cooling towerbeing Locked Out:

1. Fan Fail To Start (Start/Stop is ON and Status is OFF after pre-set internal timetolerance; Default = 30 sec (adjustable), (Reset Required)

2. Fan Active Trip Alarm (Reset Required)3. Fan Manual OFF condition (Mode = Remote and Status = OFF After preset

Internal Time tolerance; Default = 120 Sec (Adjustable)4. Cooling Tower Maintenance Mode (Maintenance Mode S/W switch is

Enable).5. Cooling Tower Fan Cell has an active low or high level alarm.

Once a cooling tower has been locked out then the next cooling tower in the sequencewill be commanded to start. If no cooling tower is available however and there aresome fans still available then the tower will not be locked out but will continue to runwith the available fans.

Upon reset of the Fault condition at the control panel or in the field the coolingtower will remain Locked Out of the sequence until the Fault condition has beenmanually acknowledged and reset by the operator or building engineer by means of amanual command signal on the relevant graphic display on the operators terminal ofthe Building Management System.

Once the Fault condition has been acknowledged and reset by the operator thecooling tower will be returned to its original position in the staging sequence in anorderly manner.

As detailed earlier some cooling towers have differing numbers of cells. Coolingtower lockout will depend on the number of cells that are deemed to have failed.The number of failed cells that will determine a cooling tower lockout will be operatoradjustable and the default values will be initially set up as follows:-



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Fan Cells Cell Failure Setpoint7 Cell Tower 14 Cell Tower 13 Cell Tower 1

In the event that a cooling tower has fans that are unavailable and there are no othercooling towers available to operate then the tower will not be locked out but willcontinue to operate with the remaining fans until such a time as another similar sizecooling tower is available. When the fans are once again available they will be startedautomatically.



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1.5 Monitoring of Auto / Manual Control Switches

Individual Auto / Off / Manual switches are installed within the mechanicalelectrical switch board for the following:

Chillers Chilled Water Pumps Condenser Water Pumps Cooling Towers Fans

An auxiliary voltage free contact associated with the Auto position of each switch isconnected as a digital input signal into the Honeywell DDC system and the contactsclose whenever the switch is in the Auto position.

Should any switch not be in the Auto position then an alarm condition is enunciatedon the relevant chiller set system graphic display on the operator terminal of theBuilding Management System.

1.6 System Maintenance Mode

To enable the chiller sets and cooling towers to be taken Out Of Service for routinemaintenance an override facility is provided on the chiller set graphic display on theoperator terminal of the Building Management System.

The Out Of Service function will be entered by manual commands from the operatorterminal.

During the period that the chiller set Out Of Service command is active the affectedequipment will be treated as unavailable and will be Locked Out of the associatedsequence and all alarms will be inhibited.



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1.7 Chiller Set Staging Control1.7.1 General Overview

The Lead chiller set and cooling towers are started from a Cooling call signalfrom the DDC controllers serving the air handling and fan coil units for the building.

The signal is Globally transferred from the air handling and fan coil unit DDCcontrollers to the chiller system DDC controller.

The Cooling call signal will be transferred from the air handling unit controller(s) tothe chiller system controller whenever any field air handling or fan coil unit coolingcoil control valve actuator is 80% open (Adjustable) AND the unit status is in theactive state.

A time schedule is also included and whenever the time schedule is in the off statethen the cooling call is ignored and the system is disabled. The time schedule willinitially be set to 24/7 operation.

The time schedule will have the following states:

Off Day Mode Night Mode

Whenever the chiller time schedule is in the Off state then the system will beshutdown.

When the system is in day mode all chillers will be available to operate and theLead chiller will be set to the Lead of the three 1030 Ton capacity chillers.Irrespective of which chiller is set as the lead the system will always stage down to theleast capacity chiller whenever the system load allows.

Night mode is intended for low load times such as after normal hours, weekends andpublic holidays. In this mode all chillers will be available to operate according to thesystem load but the Lead chiller will be set to the 350 Ton capacity chiller. The duty515 ton chiller can be set as the lead with a simple operator change.

The time program schedule can be changed and customised to suit the particularapplication. The default schedule is as follows (24 Hour, 7 day operation):



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Day Off Mode Night Mode Day Mode

Monday - 00:00 - 08:0018:00 - 24:00 08:00 - 18:00

Tuesday - 00:00 - 08:0018:00 - 24:00 08:00 - 18:00

Wednesday - 00:00 - 08:0018:00 - 24:00 08:00 - 18:00

Thursday - 00:00 - 08:0018:00 - 24:00 08:00 - 18:00

Friday - 00:00 - 08:0018:00 - 24:00 08:00 - 18:00

Saturday - 00:00 - 08:0013:00 - 24:00 08:00 - 13:00

Sunday - 00:00 - 24:00 -Holiday - 00:00 - 24:00 -Note:Sunday/ Public Holiday : Upon request by tenantAfter Office Hours : Upon request by tenant

Cooling towers are sequenced separately so whenever a chiller is to be commanded tostart then the cooling towers are started in their sequence according to the coolingtower staging section of this document.

In general the number of chillers that can be in operation is always limited by theavailable capacity of cooling towers.

Refer to the staging table later in this section for details.

1.7.2 Chiller Start-Up and Shut-Down Sequence

Whenever a chiller set is commanded On the following control action will occur insequence.

a) The chiller condenser water shut off valve will be commanded to open.b) Upon receipt of an On status from the above valve the condenser water pump in

will be commanded to start.c) Upon receipt of an On status from the condenser water pump flow switch then

the next cooling tower in the sequence will be enabled.d) Upon receipt of an On status from the cooling tower then the chiller chilled

water shut off valve will be commanded to open.



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e) Upon receipt of an On status from the above valve the chilled water pump willbe commanded to start.

f) Upon receipt of an On status from the chilled water pump flow switch the chillerwill be Enabled.

Whenever the chiller set has been commanded Off the following control action willoccur in sequence.

a) The chiller Enable signal will be de-energised.b) When the chiller set status signal has returned to Off a time delay period of 10

seconds (Adjustable) will be invoked after which the chilled water pump will becommanded Off followed immediately by the chilled water shut off valve.

c) After a further time delay period of 180 seconds (Adjustable) the condenser waterpump will also be commanded Off followed immediately by the condenser watershut off valve and the cooling tower if required to stop.

1.7.3 Staging On of Lag Chiller Sets

After the Lead chiller set has started and a stabilising time delay period of 15minutes (Adjustable) has expired, the next available chiller set in the control sequencewill be commanded to start whenever either of the following condition arises for acontinuous period of 300 Seconds (Adjustable) :-

The System Load Tonnage remains above the Stage Up setpoint The common primary chilled water supply temperature is greater than 10 C

(Adjustable)After a Lag chiller set has been commanded On a stabilising delay period of 15minutes (Adjustable) will be invoked before the next available chiller can be started.

Depending on the system load subsequent chillers will be started in sequence until allavailable units are on line and operational. The Stage Up setpoints are detailed in thesection Staging Table.

1.7.4 Staging Off of Lag Chiller Sets

The trailing chiller set in the control sequence will be commanded to stop wheneverthe following condition arises:-

The System Load Tonnage remains below the Stage Down setpoint for acontinuous period of 300 seconds (Adjustable).



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After a Lag chiller set has been commanded Off a stabilising delay period of 5minutes (Adjustable) will be invoked before the next trailing chiller set can bestopped.

Depending on the system load subsequent chillers will be stopped in sequence untilonly a single chiller set is on line and operational. The Stage Down setpoints aredetailed in the section Staging Table.

1.7.5 Staging Table

The stage On setpoint is calculated as follows:-

Stage On Setpoint (Ton) = Adjustable Percentage (%) X Total RunCapacity (Ton)

The stage Off setpoint is calculated as follows:-

Stage Off Setpoint (Ton) = Adjustable Percentage (%) X (Total Run Capacity Capacity of Next Chiller Off)

Where:

Adjustable Percentage = adjustable percentage divided by 100, default values aregiven in the table under the columns Stage Up (%) and Stage Down (%)

Total Run Capacity = the total capacity in RT of all chillers that are currentlyoperating (indicated in the column Online Capacity)

Capacity of Next Chiller Off = the capacity in RT of the next chiller that issequenced to be commanded off. For example staging down from 2060 ton to 1380ton requires one 1030 ton chiller to be stopped and one 350 ton chiller to be started. Inthis case the next off capacity will be 1030 350.

The Staging set point values for the system are detailed in the table below. The tableshows both the stage up and stage down setpoints in RT and the percentage of thecurrent chiller online capacity. All values are fully adjustable.

The number shown after the OFF 1 in the table indicates the sequence in which chillerswill be started under failure scenarios. For example 1 indicates that this chiller willstart if any of the operating chillers fail, 2 indicates that this chiller will be started if



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the chiller with 1 is unavailable and so on. Where there are chillers with numbers ofthe same value then both chillers will be started.

OnlineCapacity

Stage UpRT / %

Stage DownRT / %

Lead(1030)

Lag1(1030)

Lag2(1030)

Duty(515)

Standby

(515)350

3440 N/A 2064(67%) ON ON ON OFF 1 OFF 2 ON

3090 2408(78%)1854

(90%) ON ON ON OFF 1 OFF 2 OFF 1

2060 2039(99%)1242

(90%) ON ON OFF 1 OFF 2 OFF 3 OFF 2

1380 1366(99%)927

(90%) ON OFF 1 OFF 2 OFF 3 OFF 4 ON

1030 1020(99%)463

(90%) ON OFF 1 OFF 2 OFF 3 OFF 4 OFF 3

515 510(99%)315

(90%) OFF 2 OFF 3 OFF 4 ON OFF 1 OFF 5

350 346(99%) N/A OFF 3 OFF 4 OFF 5 OFF 1 OFF 2 ON

1.7.6 Calculation of Building Load

The Building Load expressed as Ton is used to stage the chillers On and Offand is calculated as described:

The actual load in the field is calculated using the following formula.

kWr = Flow X TD X 4.187Where:-

Flow = Total Chilled water flow rate of operating chiller sets in litres /second.

TD = Common primary return temperature minus common supplytemperature.

4.187 = The constant for specific heat capacity of water.

The total chilled water flow rate is determined from the flow meters installed in thetwo common discharge piping from the chillers.

The refrigeration tonnage is also calculated within the software program of the DDCcontroller and is used in the sequencing control module.



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Tonnage = 0.2856 X kWR

The instantaneous thermal tonnage value is then used to stage the trailing chiller setsin the staging sequence as detailed in the previous section.

The chillers are staged in order to meet the system efficiency requirements (based on apercentage of the total duty load of 3440 Ton):

8.33% to 20% = 0.65 kW/Ton 20% to 100% = 0.6 kW/Ton



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1.8 Chilled Water Pump VSD control

Differential pressure sensors are installed across the main chilled water flow andreturn lines in each of the four risers adjacent to the Index air handling unit.

The sensors are connected as analog inputs into the Honeywell DDC controller and thedifferential pressures are monitored whenever a chiller set primary chilled water pumpis operating.

Each differential pressure sensor will have a separate setpoint assigned. Thedifferential pressure and the setpoint of each sensor are compared and the deviationfrom setpoint calculated. The deviation from setpoint is used to reset the chilled waterflow setpoint as detailed below. A software switch is included to allow the operator toselect between the following strategies:

Average deviation from setpoint of the four risers (default) Maximum deviation from setpoint of the four risers

Should any of the four differential pressure sensors be in a faulty condition then thatsensor will be automatically excluded from the calculation.

The speed of the operating chiller set primary chilled water pumps is reset frommaximum to minimum design flow rate values to maintain the required differentialpressure set point across the system flow and return lines under all load conditions.

As the selected differential pressure deviation in the field increases the flow ratethrough the operating chiller sets will be driven towards the minimum design flow ratevalue and as the selected differential pressure deviation decreases below zero the flowrate will be driven towards the maximum design flow rate value.

Should the selected differential pressure deviation in the field fall below minus 10 kPa(Adjustable) for a continuous period of 2 minutes (Adjustable) then the followingcontrol action will occur.



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a) The chilled water flow set point of the operating chiller sets will be raised inincrements of 2 litres / second for every 5 minute time interval until the requiredfield differential pressure set point value has been reached. At this time the controlaction will cease and the speed of the operating chiller set primary chilled waterpumps will be maintained at this value.

b) Should the chilled water flow set point of all operating chiller sets be raised to themaximum design flow rate value then the control action will be maintained at thatset point irrespective of the field differential pressure value.

Should the selected differential pressure in the field rise above plus 10 kPa(Adjustable) for a continuous time period of 2 minutes (Adjustable) then the followingcontrol action will occur.

a) The chilled water flow set point of all operating chiller sets will be decreased inincrements of 2 litres / second for every 5 minute time interval until the requiredfield differential pressure set point value has been achieved. At this time thecontrol action will cease and the speed of the operating chiller set primary chilledwater pumps will be maintained at this value.

b) Should the chilled water flow set point of all operating chiller sets be reduced tothe minimum design flow rate value then the control action will be maintained atthat set point irrespective of the field differential pressure value.

Whenever a Lag chiller set primary chilled water pump is commanded On theoutput signal from each control module is to be identical so that the speed of alloperating pumps is controlled at the same speed setting.

The default set points for all four chilled water system differential pressure sensorswill initially be set as detailed in the table:

DP sensor Location DP Setpoint(kPa)Riser 1 120Riser 2 120Riser 3 120Riser 4 120

The total chilled water flow rate is determined from the flow meters installed in thetwo common discharge piping from the chillers.

The chilled water flow setpoints are determined by the maximum and minimum flowrates of all chillers currently in operation. For example if CH-BP-01 and CH-BP-04only are operating then the maximum and minimum flow setpoints will be:



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Maximum Flow = 123.28 + 41.9 = 165.18 litres/s Minimum Flow = 43.61 + 21.48 = 65.09 litres/s

The maximum and minimum flow rates for each chiller are detailed in the table:

ChillerDesign

(Maximum) Flow(L/S)

Minimum Flow(L/S)

CH-BP-01 123.28 43.61CH-BP-02 123.28 43.61CH-BP-03 123.28 43.61CH-BP-07 41.9 13.67CH-BP-04 61.64 21.48CH-BP-05 61.64 21.48

An input signal of 2 - 10 Volts D.C. is provided to the pumps variable frequency driveunits from the DDC and the input signal will modulate the output of the drive unitfrom the minimum set speed to the maximum set speed. The minimum and maximumset speeds for the Chilled water pumps are set and adjusted within the variablefrequency drive unit by the mechanical contractor and mimicked in the DDC software.

The proportional plus integral control module within the controller will have thefollowing default values:.

a) Set Point (L/S) Calculatedb) Throttling Range 1000 L/S (initial value only)c) Integral Time 30 Seconds (initial value only)d) Minimum Speed Setting 35Hze) Maximum Speed Setting 50Hz

Note: Tuning of the PI parameters will be required during commissioning.



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1.9 Chilled Water Bypass Valve Control

A bypass valve is installed across the common flow and return lines of the chilledwater system. The valve is fitted with a Honeywell electric valve actuator whichaccepts a 2 - 10 volt D.C. signal from a hard wired analog output signal from the DDCcontroller.

Whenever all of the chiller sets are Off line the by-pass valve will be driven to thefully closed position with an input signal of 2 volts D.C.

Whenever a chiller set primary chilled water pump is commanded On the bypassvalve will be maintained in the closed position for a minimum time delay period of 2minutes (Adjustable) to enable the chiller set flow control system to stabilise.

Should the flow rate through an operating chiller set fall below the minimum designvalue then the chilled water system bypass valve will be driven towards the openposition to maintain the flow rate at or above the minimum design value.

In addition should the flow rate through any operating chiller set fall below theminimum design value then an Alarm condition will be enunciated on the relevantchiller set system graphic display on the operator terminal of the BuildingManagement System.



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1.10 Condenser Water Pump VSD control

All condenser water pumps are variable speed devices controlled from individualvariable frequency drive units.

Whenever a condenser water pump is commanded On the flow control system isEnabled to operate.

The condenser water flow rate is monitored by means of magnetic flow metersinstalled in the common condenser water return line from each of the chillers. Theoutput signal from the flow meter is connected as an analogue input into a proportionalplus integral control module within the Honeywell DDC controller. The output signalsfrom the control module are connected into the condenser water pump variable speeddrive units.

The summation of the flow rate from each of the operating chillers is calculated withinthe DDC controller and is used to control the VSD of all operating pumps.

Similarly the summation of all operating chiller design flow rates is calculated withinthe DDC controller and this value is then used as the flow setpoint.

The condenser water pump variable speed drives are modulated in unison in order tomaintain the condenser water flow rate at setpoint under all load conditions. Shouldthe flow rate fall below the setpoint then the VSD speed is modulated up towards themaximum speed. Should the flow rate rise above the setpoint then the VSD ismodulated down towards the minimum speed setting.

Should the flow rate fall below the setpoint by 50 L/S (adjustable) then an Alarmcondition is enunciated on the relevant chiller system graphic display on the operatorterminal of the Building Management System.

The condenser water design flow rates are detailed in the following table:-

Chiller Condenser WaterFlow DesignRange Of Flow

Meter1030 Ton 204 L/S

0 - 300 L/S515 Ton 102 L/S350 Ton 74.6 L/S

An input signal of 2 - 10 Volts D.C. is provided to the pumps variable frequency driveunits from the DDC and the input signal will modulate the output of the drive unitfrom the minimum set speed to the maximum set speed. The minimum and maximum



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set speeds for the condenser water pumps are set and adjusted within the variablefrequency drive unit by the mechanical contractor and mimicked in the DDC software.

The proportional plus integral control module within the controller will have thefollowing default values:.

f) Set Point Calculation based on running chillersg) Throttling Range 1000 L/S (initial value only)h) Integral Time 30 Seconds (initial value only)i) Minimum Speed Setting 35Hzj) Maximum Speed Setting 50Hz

Note: Tuning of the PI parameters will be required during commissioning.

.



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1.11 Cooling Tower System Control

The number of cooling towers in operation and the speed of the operating fans will bedetermined by the actual chiller online capacity.

The percentage load will be used to determine the number of cooling towers enabled atany one time.

In addition to using the percentage load, the following condition will also trigger thenext available cooling tower to operate:

The condenser water supply temperature is greater than 29.5 C (Adjustable)The total capacity of the system is 3,440 tons, so the system will be fully loaded(100%) when the system load is at this value. All subsequent load percentages will bebased on a percentage of this maximum system load of 3,440.

For example the system is considered at 50% loaded when the system load is at 50%of 3,440 tons or 1,720 tons.

The following table details the relationship between the number of towers enabled andthe system online capacity:

OnlineCapacity

(%)Online

Capacity(RT)

LeadCT1~3

Lag1CT1~3

Lag2CT1~3

Duty(515)

Duty(515)

100 3440 ON ON ON ON ON95 3268 ON ON ON ON ON90 3096 ON ON ON ON ON80 2752 ON ON ON ON ON75 2580 ON ON ON ON ON70 2408 ON ON ON ON ON60 2064 ON ON ON ON ON50 1720 ON ON ON ON ON40 1376 ON ON ON OFF OFF30 1032 ON ON OFF OFF OFF20 688 ON OFF OFF OFF OFF8 275 ON OFF OFF OFF OFF

Once cooling towers are enabled all associated fans will be commanded to start andthe VSD speed of all operating fans will be controlled in unison according to the nextsection.



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1.11.1Cooling Tower Fan VSD Control

A temperature sensor is installed in the common condenser water supply line from thecooling towers and is connected into a proportional + integral control module withinthe Honeywell DDC controller. The output signal from the control module isconnected to the associated cooling tower fan variable frequency drive units.

The temperature control system for each cooling tower is Enabled to operatewhenever a cooling tower fan is running.

As the common condenser water temperature rises above set point the speed of theoperating cooling tower fans will be increased to maintain the water temperature at therequired set point value.

Should the common condenser water temperature fall below the set point value thenthe output to the operating fan variable frequency drive units will be modulatedtowards the minimum speed.

Whenever more than one cooling tower system is required to operate the variablefrequency drive units of the operating cooling tower fans will be controlled from acommon output signal from the DDC controller so that each fan is controlled at thesame speed.

Whenever a lag cooling tower system is initially commanded On the speed of theoperating cooling tower fans is reduced to 50% (Adjustable) of the design speed andthe input signal into the lag cooling tower fan variable frequency drive unit is slowlyramped up to operate the fan at 50% of the design speed. The speed of the fans ismaintained at this value for a continuous time period of 2 minutes (Adjustable) toallow the temperature control system to stabilize. At the expiration of the time delayperiod the fans are controlled in a parallel arrangement to maintain the requireddischarge temperature set point value from the operating cooling towers.

The control of the operating cooling tower fans from the common condenser watersupply temperature sensor is depicted in the following diagram.



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The temperature control module for the cooling tower fans will be set up with thefollowing default parameters.

a) Set Point = 29.5 C (Adjustable)b) Throttling Range = 100 C.c) Integral Time = 20 seconds.

As detailed the number of cooling towers in operation will be determined by thesystem load. To prevent cycling of towers adjustable hysteresis is included as detailedin the diagram below. As well as hysteresis adjustable time delay is also includedbetween cooling tower steps.



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1.12 System Energy MonitoringElectrical Power Meters are installed and monitored by the BMS system to monitor theelectrical KW for the following equipment:-

Chiller Sets Chilled Water Pumps Condenser Water Pumps Cooling Towers

The total KW is summed for all operating equipment and displayed on a relevantcustom graphic.

As mentioned previously the system load is calculated in both Tonnage and KWRunits these values are also displayed on the custom graphics.

A calculation of plant efficiency is carried out as follows:-

Total Electrical KW divided by System Tonnage(System Efficiency = KW/Tonnage)

This value of system efficiency is displayed on the custom graphics and is alsoincluded in a system trend on a 24/7 basis. Custom reports can then be generated totrack the efficiency of the system over time.

The chillers are staged in order to meet the system efficiency requirements (based on apercentage of the total duty load of 3440 Ton):

8.33% to 20% = 0.65 kW/Ton 20% to 100% = 0.6 kW/Ton



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1.13 Heat Balance Calculation and Monitoring

The heat balance is calculated as detailed in this section.

The heat balance percentage is calculated within the DDC controller and is displayedon the operators terminal of the Building Management System. The values are alsotrended for graphical monitoring and archived for future retrieval if required.

If more than 20% of the computed heat balance percentage values are not within the5% range then an indication will be given on the relevant system graphic.

The heat balance percentage will be calculated within the DDC controller at oneminute intervals (stored for one year recording) and the percentage of the sampleswithin the 5% range will be calculated and displayed in the following formats.

Current - Current percentage taken in 10 minute windowsThis Hour - Percentage for the current hour (updated every minute)Last Hour - Percentage for the previous hourToday - Percentage today (updated every minute)Yesterday Percentage for the previous dayThis month - Percentage for current month (updated every minute)Last Month - Percentage for the previous month

The temperature readings and water flow rate are connected directly to the field BTUcalculator having a 16 bit A/D resolution to comply to Green Mark version 4.

The heat balance is represented by the following equation:

qcondenser = qevaporator + Winput

Where

qcondenser = Heat Rejectedqevaporator = Cooling LoadWinput = Measured electrical power input to compressors

The following pressure enthalpy diagram shows the concept of heat balance equationin a vapour compression cycle:



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The computation of the heat balance percentage (the total heat gain and total heatrejected) is calculated using the following equation:Percent Heat balance = [(qevaporator + Winput - qcondenser) / qcondenser] X 100%

The aim here is that the total heat gain and the total heat rejected must be within 5%for 80% of the sampled points.

NOTE: For open drive chillers the Winput shall take into account the motor efficiencyprovided by the manufacture. For example if the efficiency is 90% and the measuredinput power is 100Kw then the value used in the calculation will be 90% of 100Kw =90kW.

The individual values in the heat balance equation are derived as follows:

qevaporator = 4.19 X CHW Flow X (CHWRT CHWST)

qcondenser = 4.19 X CW Flow X (CWRT CWST)

Winput = Sum of chillers input electrical power kW (readings are taken from the powermeters installed within the chiller electrical switchboards and interfaced to the DDCcontroller via a Modbus RS485 connection)

The diagram below shows the actual BP Office chiller system and how the aboveequation is derived from actual installed devices.



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A: qevaporator= 4.19 X CHW FlowFM-1 X (CHWRT1 CHWST1) + 4.19 X CHW FlowFM-2 X (CHWRT2 CHWST2)

B: qcondenser= 4.19 X CW FlowFM-3 X (CWRT CWST)

C: Winput = Sum of chillers input electrical power kW

Percent Heat Balance = [(A + C) B] / B x 100%



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The diagram below shows an example of a successful heat balance calculation wheremore than 80% of the computed values fall within 5% range.



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1.14 Hardware Point Summary Chilled Water Headers, Bypass and DP sensors(For the two headers each tag name is preceded with Chw-Hdr-0X, where X= HeaderNumber. For the bypass system the tag name is preceded with CH-Bypass)

Tag Name Description PointTypeSignalType

SensorRange Eng Unit

_ChwST Header 1 CHW Supply Temp. AI PT1000 PT1000 C_ChwRT Header 1 CHW Return Temp. AI PT1000 PT1000 C_ChwFlw Header 1 CHW Supply Flow AI 2-10V TBA l/s_SPres Header 1 CHW Supply Pressure AI 2-10V TBA kPa_RPress Header 1 CHW Return Pressure AI 2-10V TBA kPa

_ChwST Header 2 CHW Supply Temp. AI PT1000 PT1000 C_ChwRT Header 2 CHW Return Temp. AI PT1000 PT1000 C_ChwFlw Header 2 CHW Supply Flow AI 2-10V TBA l/s_SPres Header 2 CHW Supply Pressure AI 2-10V TBA kPa_RPress Header 2 CHW Return Pressure AI 2-10V TBA kPa

_InPres Bypass Line Inlet Pressure AI 2-10V TBA kPa_OutPress Bypass Line Outlet Pressure AI 2-10V TBA kPa_VlvFdb Bypass Valve Feedback AI 2-10V 0-100% %_Vlv Bypass Valve Control AO 2-10V 0-100% %

_DiffPres1 Differential Pressure Sensor 1 AI 2-10V TBA kPa_DiffPres2 Differential Pressure Sensor 2 AI 2-10V TBA kPa_DiffPres3 Differential Pressure Sensor 3 AI 2-10V TBA kPa_DiffPres4 Differential Pressure Sensor 4 AI 2-10V TBA kPa

Condenser Water Header(Each tag name is preceded with Cnw-Hdr)



_CnwST Header 1 CHW Supply Temp. AI PT1000 PT1000 C_CnwRT Header 1 CHW Return Temp. AI PT1000 PT1000 C



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Chilled Water Pumps(Each tag name is preceded with CHWP-BP-0X, where X = Pump Number)



_SPres Pump Inlet Pressure AI 2-10V TBA kPa_RPress Pump Outlet Pressure AI 2-10V TBA kPa_VSDFdb Variable Speed Drive Feedback AI 0-10V 0-100% %_Sts Pump Run Status DI N/O Open=Off Off/On_Mode Pump Mode Switch Input DI N/O Open=TBA Local/Remote_Trip Pump Trip Input DI N/C Open=Trip Norm/Alarm_VSD Variable Speed Drive Control AO 2-10V 0-100% %_SS Pump Start / Stop Control DO N/O Open=Off Off/On

Condenser Water Pumps(Each tag name is preceded with CNWP-BP-0X, where X = Pump Number)



_SPres Pump Inlet Pressure AI 2-10V TBA kPa_RPress Pump Outlet Pressure AI 2-10V TBA kPa_VSDFdb Variable Speed Drive Feedback AI 0-10V 0-100% %_Sts Pump Run Status DI N/O Open=Off Off/On_Mode Pump Mode Switch Input DI N/O Open=TBA Local/Remote_Trip Pump Trip Input DI N/C Open=Trip Norm/Alarm_VSD Variable Speed Drive Control AO 2-10V 0-100% %_SS Pump Start / Stop Control DO N/O Open=Off Off/On

Chillers(Each tag name is preceded with CH-BP-0X, where X = Chiller Number)



_Sts Chiller Run Status DI N/O Open=Off Off/On_ChwFlowSts CHW Flow Switch Status DI N/O Open=Off Off/On_CnwFlowSts CDW Flow Switch Status DI N/O Open=Off Off/On_Mode Chiller Mode Switch Input DI N/O Open=TBA Local/Remote_Trip Chiller Fault Input DI N/O Open=Norm Norm/Alarm_ChwVlvSts CHW Shut Off Valve Status DI N/O Open=Close Close/Open



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_CnwVlvSts CDW Shut Off Valve Status DI N/O Open=Close Close/Open_Setpoint Chiller Remote Setpoint AO 2-10V TBA C_ChwVlvCtrl CHW Shut Off Valve Control DO N/O Open=Close Close/Open_CnwVlvCtrl CDW Shut Off Valve Control DO N/O Open=Close Close/Open_SS Chiller Start / Stop Control DO N/O Open=Off Off/On

Chillers (Sensors)(Each tag name is preceded with CH-BP-0X, where X = Chiller Number)



_ChwInPress Evaporator In Water Pressure AI 2-10 V TBA kPa_ChwOutPress Evaporator Out Water Pressure AI 2-10V TBA kPa_ChwFlw Evaporator Water Flow AI 2-10V TBA l/s_ChwInTemp Evaporator In Water Temp AI PT1000 PT1000 C_ChwOutTemp Evaporator Out Water Temp AI PT1000 PT1000 C_CnwInPress Condenser In Water Pressure AI 2-10 V TBA kPa_CnwOutPress Condenser Out Water Pressure AI 2-10V TBA kPa_CnwFlw Condenser Water Flow AI 2-10V TBA l/s_CnwInTemp Condenser In Water Temp AI PT1000 PT1000 C_CnwOutTemp Condenser Out Water Temp AI PT1000 PT1000 C

Cooling Towers Cells(Each tag name is preceded with CT-BP-X-Y, where X = CT Number and Y = CellNumber)



_InletTemp CT Cell Inlet Temperature AI PT1000 PT1000 C_OutletTemp CT Cell Outlet Temperature AI PT1000 PT1000 C_FanVSDFdb Fan Variable Speed Feedback AI 0-10V 0-100% %_FanSts Fan Run Status DI N/O Open=Off Off/On_FanMode Fan Mode Switch Input DI N/O Open=TBA Local/Remote_FanTrip Fan Trip Input DI N/O Open=Norm Norm/Alarm_LvlLo CT Cell Low Level Alarm DI N/O Open=Norm Norm/Alarm_LvlHi CT Cell High Level Alarm DI N/O Open=Norm Norm/Alarm_FanVSDFdb Fan Variable Speed Control AO 0-10V 0-100% %_FanSS Fan Start / Stop Control DO N/O Open=Off Off/On



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1.15 High Level Point Summary Chillers (From Power Meters)(Each tag name is preceded with CH-BP-0X, where X = Chiller Number)

Tag Name Description RegisterTypeRegisterAddress Eng Unit

_AmsA Chiller Phase A Amps Holding TBA Amps_AmpsB Chiller Phase B Amps Holding TBA Amps_AmpsC Chiller Phase C Amps Holding TBA Amps_VoltsA Chiller Phase A to Neutral Volts Holding TBA Volts_VoltsB Chiller Phase B to Neutral Volts Holding TBA Volts_VoltsC Chiller Phase C to Neutral Volts Holding TBA Volts_kWh Chiller Power Consumption Holding TBA kWh_kW Chiller Power Demand Holding TBA kW

Chilled Water Pumps (From Power Meters)(Each tag name is preceded with CHWP-BP-0X, where X = Pump Number)


_AmsA Pump Phase A Amps Holding TBA Amps_AmpsB Pump Phase B Amps Holding TBA Amps_AmpsC Pump Phase C Amps Holding TBA Amps_VoltsA Pump Phase A to Neutral Volts Holding TBA Volts_VoltsB Pump Phase B to Neutral Volts Holding TBA Volts_VoltsC Pump Phase C to Neutral Volts Holding TBA Volts_kWh Pump Power Consumption Holding TBA kWh_kW Pump Power Demand Holding TBA kW



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Condenser Water Pumps (From Power Meters)(Each tag name is preceded with CNWP-BP-0X, where X = Pump Number)


_AmsA Pump Phase A Amps Holding TBA Amps_AmpsB Pump Phase B Amps Holding TBA Amps_AmpsC Pump Phase C Amps Holding TBA Amps_VoltsA Pump Phase A to Neutral Volts Holding TBA Volts_VoltsB Pump Phase B to Neutral Volts Holding TBA Volts_VoltsC Pump Phase C to Neutral Volts Holding TBA Volts_kWh Pump Power Consumption Holding TBA kWh_kW Pump Power Demand Holding TBA kW

Cooling Tower Fans (From Power Meters)(Each tag name is preceded with CT-BP-X-Y, where X = CT Number and Y = CellNumber)


_AmsA Cooling Tower Fan Phase A Amps Holding TBA Amps_AmpsB Cooling Tower Fan Phase B Amps Holding TBA Amps_AmpsC Cooling Tower Fan Phase C Amps Holding TBA Amps_VoltsA Cooling Tower Fan Phase A to Neutral Volts Holding TBA Volts_VoltsB Cooling Tower Fan Phase B to Neutral Volts Holding TBA Volts_VoltsC Cooling Tower Fan Phase C to Neutral Volts Holding TBA Volts_kWh Cooling Tower Fan Power Consumption Holding TBA kWh_kW Cooling Tower Fan Power Demand Holding TBA kW



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Chiller High Level Interface (From Chiller Processor)(Each tag name is preceded with CH-BP-0X, where X = Chiller Number)


TBA BAS Base Loading Enable BV1 40007TBA BAS Base Loading Setpoint AV4 40006TBA BAS Chilled Water Setpoint AV1 40003TBA BAS Chiller Auto Stop Command MV1 40001TBA BAS Chiller Mode Command MV2 40002TBA BAS Current Limit Setpoint AV2 40004TBA BAS Diagnostic Reset BV2 40008TBA BAS Hot Water Setpoint AV3 40005TBA Base Loading B19 30046TBA Calculated Chiller Capacity AI5 30008TBA Carbon Tank Temp AI39 30071TBA Chiller Control Mode MI2 30027TBA Chiller Running BI1 30003TBA Chiller Running Status MI1 30026TBA Compressor Refrigerant Discharge

Temperature AI36 30065

TBA Compressor Running MI11 30055TBA Compressor Running Time AI49 30088TBA Compressor Starts AI48 30086TBA Cond Differential Wtr Press AI15 30022TBA Cond Entering Water Temp AI10 30013TBA Cond Leaving Water Temp AI11 30014



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1.16 Chilled Water Schematic

Chiller System BMS

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