Open Protocol Data Communications

MicroTech Series-100 Centrifugal Chiller Open Protocol Data Communications Information Packet Version 3.2 April, 1996

- C O N F I D E N T I A L - This Document may not be copied or reproduced in any way without the express written consent of McQuay International. NOTICE Copyright 1994, 1996 McQuay International, Minneapolis MN All rights reserved throughout the world. McQuay International reserves the right to change any information contained herein without prior notice. No guarantees are given as to the accuracy of information provided. ii

Contents Revision History 5 Version 3.2...5 Overview 7 Introduction to Series-100 Centrifugal Chillers...7 Centrifugal Products included in this Open Protocol Document...8 Series-100 Centrifugal Chiller Input/Output Configuration 9 Analog Inputs...9 Digital Inputs...10 Digital Outputs...10 Control Modes for the Series-100 Centrifugal Chiller 11 Sequence of Operation...11 Description of Modes...13 Start Requested...13 Waiting, Low Oil Sump Temperature...13 Evaporator Pump On...13 Waiting for Load...13 Oil Pump On...13 Condenser Pump On...13 Startup Unloading...14 Motor Control Relay Started...14 Running OK...14 Off: Load Recycle...14 Off: Time Clock...14 Off: Remote Signal...14 Off: Manual Switch...14 Off: Network Signal...14 Begin Routine Shutdown...15 Motor Control Relay Off, Post Lube...15 Begin Rapid Shutdown...15 Off: Fault...15 Hardware 17 MicroTech Controller Hardware Interfacing...17 Communications to a Single Chiller...17 Communications to two Chillers with a LLLB Panel...18 Communications to two or more Chillers...19 Correct Addresses for MicroTech Series-100 Centrifugal Chillers (Control Processor)...19 MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Contents 3 of 62

Variables 20 Read Only - Control Processor...20 Read and Write Memory Locations - Control Processor...33 Keypad/Display Controller Addresses...36 Read Only Memory Locations (Display processor)...37 LLLB (Lead Lag Load Balance) Controller 41 Description...41 Read Only Memory Locations for the LLLB Panel...41 Read and Write Memory Locations for the LLLB Panel...42 Series-100 Centrifugal Chiller Simulation Package 45 Required Development Testing Tools...45 Set-up of Hardware for Testing...45 Procedure for setting up the network arrangement...46 Open Protocol Monitor Program 48 Sample Screens...48 Glossary of Terms 59 Index 60 MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Contents 4 of 62

Revision History Version 3.2 Version 3.1 Version 3.0 This is a general upgrade and format change of the document. References to "SnyderGeneral Corporation" changed to "McQuay International." Corrections and amplifications (flagged with vertical revision marks; newly added text is underlined). Added Time, Year to the display processor. This was a missing location.. Added Motor Current, Amps to the control processor. This is a new memory location. Added the Watchdog Output to the control processor. This was mislabeled as another output. Added to the Current Fault memory location, fault codes 16 through 29 which were missing. Fault codes 16 to 29 are the codes used when one of the microprocessor sensors have failed. Corrected explanation of the Network Start/Stop memory location. Previous document indicated a value of 1 to 255 would stop the chiller, this has been corrected to read only the value of 255 will stop the chiller. This was a documentation error. Added Entering Evaporator Water Temp - Hi Resolution to the control processor. Added Leaving Evaporator Water Temp - Hi Resolution to the control processor. Added Evaporator Refrigerant Temp. - Hi Resolution to the control processor. Added Compressor Suction Temp - Hi Resolution to the control processor. Added Liquid Line Temp. - Hi Resolution to the control processor. Added Entering Condenser Water Temp. - Hi Resolution to the control processor. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Revision History 5 of 62

Added Leaving Condenser Water Temp. Hi Resolution to the control processor. Added Maximum Chilled Water Reset Setpoint to the control processor and added clarifying notes about how chilled water reset works. Added Reset Option memory location to the control processor. Added clarifying notes to the variables Manual Amp Limit and Maximum Amp Limit of the control processor. Added Manual Amp Limit Setpoint to the control processor. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Revision History 6 of 62

Overview Introduction to Series-100 Centrifugal Chillers Refrigerants Starting and Stopping the Chiller We manufacture two (2) types of centrifugal chillers - single compressor and dual compressor type units. The single compressor units have one MicroTech control panel. Dual compressor unit always have two MicroTech control panels (one for each compressor) and a factory mounted Lead Lag and Load Balancing Panel (LLLB) for sequencing control and load balancing logic between the two compressors. Both types of chillers can use either R12, R500 or R134a refrigerant. The control panel is factory programmed for the type of refrigerant used. In addition, we provide access to information contained in the MicroTech control panel via a unit mounted keypad/display. The keypad/display is factory programmed to display units in either English Units (i.e. F and Psi) or Metric (i.e. C and KPa). The purpose of the chiller is to produce chilled water. If there is chilled water flow, the controller will monitor the leaving chilled water temperature, compare it to the chilled water setpoint, and then start the compressor(s) and control the inlet vanes on the compressor to maintain setpoint. The chilled water setpoint can be reset from either the entering chilled water temperature, a remote 4-20 ma signal, or via Open Protocol communications. The front panel has a "Start/Stop" rocker switch. If the switch is in the "Stop" position, the chiller will not run. This switch must be in the "Auto" position in order for the chiller to start and run. If the chiller is running and the switch is changed to "Stop", the compressor motor will be turned off immediately. In the meantime, the micro-processor will perform an orderly shutdown by keeping the oil pump on and closing the vanes. The chiller can be turned on or enabled for operation several ways. First, the front panel rocker switch must be in "Auto". The "START MODE" setpoint ( 5th key press of Setup-Options Key) can be set to either "Local" or "Remote". If the keypad/display is in "Local", the chiller will be started and stopped via its internal programmed time schedule. If the keypad/display is in "Remote", the chiller will ignore its internal time schedule and will start and stop in response to the remote start/stop digital input (a contact closure to field terminals 9 & 64). MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Overview 7 of 62

Centrifugal Products included in this Open Protocol Document "*" designates a wild card, any character in this location is acceptable McQuay International manufactures MicroTech Series-100 centrifugal chillers for a wide variety of applications from ice chiller systems, to heat recovery, to templifiers (heat pumps), etc. This Open Protocol document specifically addresses standard Series-100 centrifugal chiller applications only. Before applying Open Protocol, confirm that the application has the following software identification (ID), otherwise incompatibilities may result. (Software ID's are imprinted on a label inside the control box or may be obtained by contacting the McQuay International representative). Controller Products Series Software ID Series-100 Centrifugal Chiller Control Processor 100 PC*08* Series-100 Centrifugal Chiller Display Processor 100 PDR08* Lead Lag Load Balance (LLLB) Panel 100 DUA09* In addition, software IDs are stored within the controllers. Software ID's Memory locations are as follows: Series 100 Series 200 $800A-F $0A08-F Note: Above ID's result when the resultant memory location is translated into ASCII, for example, Series-100 Centrifugal Chiller Control Processor code would have $50, $43, *, $30, $35, *. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Overview 8 of 62

Series-100 Centrifugal Chiller Input/Output Configuration Analog Inputs Reset Types Input Number Description 0 Leaving Evaporator Water Temperature 1 Entering Evaporator Water Temperature 2 Evaporator Refrigerant Temperature 3 Suction Line Temperature 4 Liquid Line Temperature 5 Entering Condenser Water Temp. 6 Leaving Condenser Water Temp. 7 Discharge Line Temperature 8 Condenser Refrigerant Temperature 9 Oil Feed Temperature 10 Oil Sump Temperature 11 Remote Reset Signal 12 Motor Current 13 Oil Pressure The remote reset signal (Analog #11) can be used to reset either of the following but not both: Chilled H2O Reset Amp Limiting MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2Series-100 Centrifugal Chiller Input/Output Configuration 9 of 62

Digital Inputs Digital Outputs Input Number Description 0 Surge Guard 1 Motor Temperature 2 Oil Differential 3 Discharge Pressure Switch 4 Low Refrigerant Pressure Switch 5 Stop/Auto Switch 6 Starter Fault 7 Condenser Water Flow Switch 8 Evaporator Water Flow Switch 9 Starter Transition 10 Remote Start/Stop 11 Vanes Closed Output Number Description 0 Unload Solenoid 1 Load Solenoid 2 Hot Gas Solenoid 3 Motor Control Latch Relay 4 Watchdog 5 Oil Heater 6 Liquid Injection Solenoid 7 Remote Alarm 8 Cooling Tower Stage 1 9 Cooling Tower Stage 2 10 not used 11 Evaporator Pump 12 Condenser Pump 13 Oil Pump 14 MCR Relay 15 LED Front Panel MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2Series-100 Centrifugal Chiller Input/Output Configuration 10 of 62

Control Modes for the Series-100 Centrifugal Chiller Sequence of Operation A typical sequence of operation is summarized in the following flow chart from System Startup to Shutdown. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Control Modes for the Series-100 Centrifugal Chiller 11 of 62

Off, Load Recycle Time Clock Remote Switch Manual Switch Network Signal Off, Ready to Start Start Requested Waiting, Low Oil Sump Temperature Evaporator Pump On Waiting for Load Oil Pump On Condenser Pump On Startup Unloading MCR On Running Ok Shutdown, Routine or Rapid Waiting, High Current Post Lubrication MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Control Modes for the Series-100 Centrifugal Chiller 12 of 62

Description of Modes Start Requested The unit must be in the Off:Ready mode to Start. If the unit is in local, the chiller can get a start request by 1.) Pressing the "Start" key on the keypad/display or 2.) Setting the internal time clock schedule to start the chiller. If the unit is in Remote, the chiller can get a start request from the remote start/stop digital input. In either of the above modes, the chiller can be commanded to stop via communications and the Network Start/Stop memory location. This memory location is the one to use to start and stop the machine via Open Protocol communications. We recommend putting the chiller in remote and installing a jumper across the Remote start/stop field terminals. The chiller will then start and run as long as the Network Start/Stop memory location does not command the chiller to stop. If the chiller has been running and the load is satisfied, the controller will turn off the compressor and go into Off: Load Recycle mode. When the anti-cycle timers are satisfied and the leaving water temp is above the setpoint plus the start-up delta temp, a start will be initiated. Waiting, Low Oil Sump Temperature If a start has been requested, the controller will check the anti-recycle timers to see if is OK to start. If the timers are satisfied, the controller will switch to Waiting, Low Oil Sump Temperature; otherwise, the mode remains at Start Requested until the anti-recycle timers are satisfied. Evaporator Pump On If the oil sump temperature is 50 F above the evaporator (adj.), the controller will turn on the evaporator pump. Flow is confirmed via the digital water flow switch. Waiting for Load If there is chilled water flow, the controller will switch to Waiting for Load. The chilled water leaving temperature has to be several degrees (adj.) over the setpoint in order to start. Oil Pump On If there is a load, the oil pump will be turned on and the vanes will be closed continuously. Condenser Pump On The condenser pump is energized. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Control Modes for the Series-100 Centrifugal Chiller 13 of 62

Startup Unloading The controller will check for condenser pump flow. Motor Control Relay Started The controller will check to see that the vanes are closed. If they are, the Motor Control Relay and Motor Control Latching Relay are turned on. Running OK If after 30 seconds there are no faults, the controller will switch to Running OK. There are two types of stop signals - Rapid Shutdown due to a fault and Routine Shutdown. Most of the time the chiller will stop because there is a Routine Shutdown. These are the Routine Shutdowns: Off: Load Recycle Off: Time Clock Off: Remote Signal Off: Manual Switch Off: Network Signal Off: Load Recycle If the leaving chilled water temperature decreases to below the setpoint minus the shut down Delta temp., the chiller will be turned off. In other words, the chiller satisfied the load. Off: Time Clock If the chiller is in Local and the internal time schedule is unoccupied, the chiller will be turned off. Off: Remote Signal If the chiller is in Remote and the Remote Start/Stop switch is opened, the chiller will be turned off. Off: Manual Switch If the rocker switch on the front panel is places in the Stop position, the chiller will be turned off. Off: Network Signal The chiller has been commanded off via network communications from another control panel or system. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Control Modes for the Series-100 Centrifugal Chiller 14 of 62

Begin Routine Shutdown If any of the above shutdowns occur, the controller will switch to Begin Routine Shutdown. During this mode, the vanes will be closed, and about one minute later, the Motor Current Relay and condenser pump will be turned off. Motor Control Relay Off, Post Lube At the beginning of this mode, the oil pump is on. 30 seconds later the oil pump is turned off. If the chiller is being shut off due to Load Recycle, the evaporator pump will stay on; otherwise, it will turned off. If the rocker switch is in the "Auto" position, the mode will switch to "Off: Ready to Start". If the rocker switch is in the "Manual" position, the mode will switch to "Off: Manual Switch". Note: A chiller that was shut down due to "Off: Load Recycle" will go through the start up phase until it gets to "Waiting for Load". Begin Rapid Shutdown At other times the chiller is shut down due to a fault. When this happens, a rapid shutdown occurs. If the oil pump wasn't turned on, the unload and post lube shutdown stages will be skipped. This means that the evaporator, condenser, and oil pumps are turned off. In addition, the Motor Control Relay is turned off and the vanes are closed. If the oil pump was on, a more normal shutdown occurs. The vanes will be continuously closed and the Motor Control Relay will already be off. The condenser and evaporator pumps will be turned off and a Post Lube sequence will occur. Off: Fault The chiller will not be allowed to run if there is a fault. The following is a listing of primary faults but does not include sensor failure faults. See Current Fault or Unit Status memory locations for a full listing. Failure of Starter Transition Switch Low Oil Sump Temperature High Oil Feed to Bearings Temperature Low Evaporator Pressure High Compressor Discharge Pressure Switch High Compressor Discharge Line Temperature SurgeGuard Protection Switch High Compressor Suction Temperature High Motor Winding Temperature Switch Starter Fault Switch Low Charge Switch Loss of Evaporator Proof of Flow Switch Loss of Condenser Proof of Flow Switch MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Control Modes for the Series-100 Centrifugal Chiller 15 of 62

Low Oil Differential Pressure Switch Low Motor Current Bad Evap Leaving Water Temperature Sensor Vanes Open During Startup MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Control Modes for the Series-100 Centrifugal Chiller 16 of 62

Hardware MicroTech Controller Hardware Interfacing The method of Open Protocol interfacing to MicroTech chillers primarily depends upon the number of chiller involved in the integration. Three scenario's are defined below and address the majority of installations. Communications to a Single Chiller One port is configured for RS- 232C, 1200 baud All McQuay MicroTech Series-100 Centrifugal Chillers are shipped from the factory with one communications port factory configured for RS-232C, 1200 baud. The port is located on the Control Processor (Cartridge Style) and is designated port A. This communication port is normally used in conjunction with a optional factory installed modem (See McQuay Installation and Maintenance Bulletin #403, pg. 42 for location of this communications Port A). Since high communication baud rates are usually desirable, it is possible to change the Port A baud rate in the field using a personal computer and the Open Protocol Monitor software program. Thus, the communications interfacing is as follows on the next page. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Hardware 17 of 62

ADDRESS 01.01 Communications to two Chillers with a LLLB Panel In this situation, two MicroTech chillers are connected to a Lead-Lag Load Balance (LLLB) panel. The LLLB panel is used in applications where there are two chillers which need to be Lead Lagged and Load Balanced. The connection point for this application is Port A on the LLLB Model 120 Controller and communications baud is factory configured to 9600 baud. Thus, the communications interfacing is as follows: MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Hardware 18 of 62

Communications to two or more Chillers In this situation, two or more MicroTech chillers are installed. If a single communications port is desired for obtaining information from all chillers, a MicroTech OPM panel is required to serve as the communications interface to all chillers. The connection point is Port A on the OPM panel and communications baud is factory configured to 9600 baud. Correct Addresses for MicroTech Series-100 Centrifugal Chillers (Control Processor) Read/Write Request Packet Control Addresses The proper values for Series-100 Centrifugal Chiller addressing is as follows, the address is used as part of the read or write request packet: "ll" "ss" Chiller No. 1 01 01 Chiller No. 2 02 01 Chiller No. 3 03 01 Chiller No. 4 04 01 Chiller No. 5 05 01 Chiller No. 5 06 01...etc. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Hardware 19 of 62

Variables Read Only - Control Processor Description Address Range Units Alarm Contact 0217 0 = deenergzd 1 = energized Approach, Condenser 0418 0-255 Calculated Leaving Evaporator Temperature Setpoint 0420 0-255 0.2*X+20= F Calculated Network Amp Limit Setpoint Compressor Discharge Temp. Compressor Suction Temp. - Lo Resolution Compressor Suction Temp. - Hi Resolution 0423 0-100 % of full load amps. 0407 0-255 F 0403 0-255 F 041C 0-255 0.2*X+20 = F Condenser Pump 021C 0 = deenergzd 1 = energized Condenser Refrigerant 0411 0-255 PSIG Pressure Condenser Refrigerant Temp. 0408 0-255 F Condenser Water Flow Switch 050F BIT 6 0 = no flow 1 = flow Cooling Tower Stage 1 0218 0 = deenergzd 1 = energized Cooling Tower Stage 2 0219 0 = deenergzd 1 = energized Current Fault 0428 See Below Fault, Last 0834 See Below MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 20 of 62

Description Address Range Units Fault 2 0835 See Below Fault 3 0836 See Below Fault 4 0837 See Below Fault 5 0838 See Below Fault 6 0839 See Below Fault 7 083A See Below Fault 8 083B See Below Entering Condenser Water 0405 0-255 F Temp. - Lo Resolution Entering Condenser Water 041E 0-255 0.2*X+55 = F Temp. - Hi Resolution Entering Evaporator Water 0401 0-255 F Temp. - Lo Resolution Entering Evaporator Water 041A 0-255 0.2*X+20 = F Temp. - Hi Resolution Entering Water Reset 0438 0 = Inactive 1 = Active Evaporator Low Pressure Switch 050E BIT 3 0 = Low press 1 = OK Evaporator Pump 021B 0 = deenergzd 1 = energized Evaporator Refrigerant 0410 0-255 PSIG Pressure Evaporator Refrigerant 0402 0-255 F Temp. - Lo Resolution Evaporator Refrigerant 041B 0-255 0.2*X+20 = F Temp. - Hi Resolution Evaporator Water Flow Switch 050F BIT 5 0 = no flow 1 = flow High Discharge Pressure Switch 050E BIT 4 0 = high press 1 = OK Hot Gas Solenoid 0212 0 = deenergzd 1 = energized Leaving Condenser Water 0406 0-255 F Temp. - Lo Resolution Leaving Condenser Water 041F 0-255 0.2*X+55 = F Temp. - Hi Resolution Leaving Evaporator Water 0400 0-255 F Temp. - Lo Resolution Leaving Evaporator Water Temp. - Hi Resolution 0419 0-255 0.2*X+20 = F MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 21 of 62

Description Address Range Units LED Front Panel 021F 0 = deenergzd 1 = energized Lift Pressure 0412 0-255 PSIG Liquid Injection Solenoid 0216 0 = deenergzd 1 = energized Liquid Line Refrigerant 0404 0-255 F Temp. - Lo Resolution Liquid Line Refrigerant 041D 0-255 0.2*X+55 = F Temp. - Hi Resolution Liquid Subcool 0417 0-255 Load Solenoid 0211 0 = deenergzd 1 = energized Low Evaporator Pressure Limit 043B 0 = Inactive 1 = Active Manual Amp Limit 043D 0 = Inactive 1 = Active Manual Amp Limit Setpoint 0901 30-100 % RLA Maximum Amp Limit 043C 0 = Inactive 1 = Active Motor Control Latch Relay 0213 0 = deenergzd 1 = energized Motor Control Relay 021E 0 = deenergzd 1 = energized Motor Current, Amps 0435, 0436 Hi Byte Lo Byte Motor Current 0-65,535 Amps Motor Current, Percent 040C 0-125 % RLA Motor Temperature Switch 050E 0 = high temp BIT 6 1 = OK Number of Starts 0432, 0433 Hi Byte Lo Byte Oil Delta Pressure 040D 0-255 PSID Oil Feed Temp. 0409 0-255 F Oil Gage Pressure 0415 0-255 PSIG Oil Heater 0215 0 = deenergzd 1 = energized Oil Pressure Differential Switch 050E BIT 5 0 = low press 1 = OK Oil Pump 021D 0 = deenergzd 1 = energized Oil Sump Temp. 040A 0-255 F Read in hex, 0-65,535 starts. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 22 of 62

Description Address Range Units Operating Hours 0430, 0431 Hi Byte, Lo Byte Panel Rocker Switch 050E BIT 2 0 = stop 1 = auto Read in hex, 0-65,535 hours. Remote Amp Limit 043E 0 = Inactive 1 = Active Remote Chilled Water Reset 0439 0 = Inactive 1 = Active Remote Reset or Amp Limit Signal, 4-20 ma 040B < 20, 20-100 4-20mA Remote Start/Stop Switch 050F BIT 3 0 = stop 1 = start Soft Load Limit 043A 0 = Inactive 1 = Active Starter Fault Switch Starter Transition Switch 050F BIT 7 050F BIT 4 0 = fault 1 = OK 0 = fault 1 = OK Superheat 0416 0-255 Surge Guard Switch 050E BIT 7 0 = surge 1 = OK Unit Status 0424 0-53 See below Unload Solenoid 0210 0 = deenergzd 1 = energized Vanes Closed Switch 050F BIT 2 0 = open 1 = closed Watchdog Output 0214 0 = deenergzd 1 = energized Alarm Contact 0217 This is used to indicate the presence of an alarm condition. A de-energized state (0) in this location indicates an alarm; an energized state (1) indicates no alarm. Approach (Condenser) 0418 This location contains the Condenser Approach Temperature in F. The approach temperature is calculated by subtracting the Leaving Condenser Water Temperature from the Condenser Refrigerant Temperature. Calculated Leaving Evaporator Temperature Setpoint 0420 This is the calculated leaving evaporator water temperature setpoint which the chiller will be controlled to taking into account any chilled water reset which may be active. To interpret this memory location, multiply by 0.2 and then add 20. The resulting setpoint after reset with a resolution of 0.2 F. See explanation under Maximum Chilled Water Reset Setpoint for more information. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 23 of 62

Calculated Network Amp Setpoint 0423 The resulting amp limit setpoint in percent after reset. Compressor Discharge Temperature 0407 This location contains the current Compressor Discharge Temperature in F. Compressor Suction Temperature - Lo Resolution 0403 This location contains the current Compressor Suction Temperature in F. For better resolution of the Compressor Suction Temperature, see the following memory location. Compressor Suction Temperature - Hi Resolution 041C This is the current Compressor Suction Temperature in 0.2 resolution. This location contains a valid value only if the temperature is between 20 F and 71 F. If this location contains a value of 0 or 255, this indicates that the current temperature is out of the 20 to 71 range. If the temperature is out of range for this location, see the above memory location (0403) for an expanded temperature range. Condenser Pump This is the status of the Condenser Pump. A "0" in this location indicates the condenser pump is off. A non zero value indicates the Condenser pump is on. 021C Condenser Refrigerant Pressure 0411 This location contains the current Condenser Refrigerant Pressure in PSIG Condenser Refrigerant Temperature 0408 This location contains the current Condenser Refrigerant Temperature in F. "x" in a bit locations means that bit is not used to determine the status. Condenser Water Flow Switch BIT 6 050F This location contains the status of the Condenser Water Flow Switch. BIT 6 is read to determine the status of the Flow Switch. A "0" in BIT 6 (x0xxxxxx) indicates no flow, and a "1" in BIT 6 (x1xxxxxx) indicates flow. Cooling Tower Stage 1 0218 This location contains the status of the output for Cooling Tower Stage 1. A "0" indicates the output is off. A non zero value indicates the output is on. Cooling Tower Stage 2 0219 This location contains the status of the output for Cooling Tower Stage 2. A "0" indicates the output is off. A non zero value indicates the output is on. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 24 of 62

Current Fault 0428 Last Fault 0834 Fault 2 0835 Fault 3 0836 Fault 4 0837 Fault 5 0838 Fault 6 0839 Fault 7 083A Fault 8 083B This section lists all of the faults and their fault codes. This list is also used for Last Fault, Fault 2, Fault 3, Fault 4, Fault 5, Fault 6, Fault 7 and Fault 8. Alarm Value No Fault 0 No Transition 1 Low Oil Sump Temperature 2 High Oil Feed to Bearings Temperature 3 Low Evaporator Pressure 4 High Discharge Pressure 5 High Discharge Temperature 6 Surge 7 High Suction Temperature 8 High Motor Temperature 9 Starter Fault 10 Low Charge 11 No Evaporator Flow 12 No Condenser Flow 13 Low Delta Oil Pressure 14 Low Motor Current 15 Bad Evap Lvg Water Sensor 16 Bad Evap Ent Water Sensor 17 Bad Evaporator Temp Sensor 18 Bad Suction Line Sensor 19 Bad Liquid Line Sensor 20 Bad Ent Cond Water Sensor 21 Bad Lvg Cond Water Sensor 22 Bad Discharge Line Sensor 23 Bad Condenser Temp Sensor 24 Bad Oil Feed Sensor 25 Bad Oil Sump Sensor 26 Bad Remote Reset 27 MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 25 of 62

Alarm Value Motor Current 28 Oil Gauge Pressure 29 Vanes Open 30 Entering Condenser Water Temperature - Lo Resolution 0405 This location contains the current Entering Condenser Water Temperature in F. For better resolution of the Entering Condenser Water Temperature, see the following memory location. Entering Condenser Water Temperature - Hi Resolution 041E This is the current Entering Condenser Water Temperature in 0.2 resolution. This location contains a valid value only if the temperature is between 55 F and 106 F. If this location contains a value of 0 or 255, this indicates that the current temperature is out of the 55 to 106 range. If the temperature is out of range for this location, see the above memory location (0405) for an expanded temperature range. Entering Evaporator Water Temperature - Lo Resolution 0401 This location contains the current Entering Evaporator Water Temperature in F. For better resolution of the Entering Evaporator Water Temperature, see the following memory location. Entering Evaporator Water Temperature - Hi Resolution 041A This is the current Entering Evaporator Water Temperature in 0.2 resolution. This location contains a valid value only if the temperature is between 20 F and 71 F. If this location contains a value of 0 or 255, this indicates that the current temperature is out of the 20 to 71 range. If the temperature is out of range for this location, see the above memory location (0401) for an expanded temperature range. Entering Water Reset 0438 This location contains the status of the Entering Water Reset. A "0" indicates that Entering Water Reset is inactive. A "1" indicates that Entering Water Reset is active. Evaporator Low Pressure Switch BIT 3 050E This location contains the status of the Evaporator Low Pressure Switch. BIT 3 is used to indicate low Pressure. A "0" in BIT 3 (xxxx0xxx) indicates low pressure. A"1" (xxxx1xxx). Evaporator Pump This locations contains the status of the Evaporator Pump Output. A "0" in this location indicates the output is off. A non zero value means the pump is on. 021B Evaporator Refrigerant Pressure 0410 This location contains the Evaporator Refrigerant Pressure in PSIG. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 26 of 62

Evaporator Refrigerant Temperature - Lo Resolution 0402 This location contain the current Evaporator Refrigerant Temperature in F. For better resolution of the Evaporator Refrigerant Temperature, see the following memory location. Evaporator Refrigerant Temperature - Hi Resolution 041B This is the current Evaporator Refrigerant Temperature in 0.2 resolution. This location contains a valid value only if the temperature is between 20 F and 71 F. If this location contains a value of 0 or 255, this indicates that the current temperature is out of the 20 to 71 range. If the temperature is out of range for this location, see the above memory location (0402) for an expanded temperature range. Evaporator Water Flow Switch BIT 5 050F This location contains the status of the Evaporator Water Flow Switch. A "0" in BIT 5 (xx0xxxxx) indicates no evaporator flow. A "1" (xx1xxxxx) indicates evaporator flow. High Discharge Pressure Switch BIT 4 050E This location contains the status of the High Discharge Pressure Switch. A "0" in BIT 4 (xxx0xxxx) indicates high discharge pressure. A "1" (xxx1xxxx) indicates normal discharge pressure. Hot Gas Solenoid 0212 This location indicates the status of the Hot Gas Solenoid output. A "0" indicates the output is off. A non zero values indicates the output is on. Leaving Condenser Temperature - Lo Resolution 0406 This is the current Leaving Condenser Water Temperature. For better resolution of the Leaving Condenser Temperature, see the following memory location. Leaving Condenser Temperature - Hi Resolution 041F This is the current Leaving Condenser Water Temperature in 0.2 resolution. This location contains a valid value only if the temperature is between 55 F and 106 F. If this location contains a value of 0 or 255, this indicates that the current temperature is out of the 55 to 106 range. If the temperature is out of range for this location, see the above memory location (0406) for an expanded temperature range. Leaving Evaporator Water Temperature - Lo Resolution 0400 This is the current Leaving Evaporator Water Temperature in 1 resolution. For better resolution of the Leaving Evaporator Water Temperature, see the following memory location. Leaving Evaporator Water Temperature - Hi Resolution 0419 This is the current Leaving Evaporator Water Temperature in 0.2 resolution. This location contains a valid value only if the temperature is between 20 F and 71 F. If this location contains a value of 0 or 255, this indicates that the current temperature is out of the 20 to 71 range. If the temperature is out of range for this location, see the above memory location (0400) for an expanded temperature range. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 27 of 62

LED Front Panel 021F This location contains the status of the output for the LED on the front panel. A "0" in this location indicates the output is off. A non zero value indicates the output is on. Lift Pressure 0412 This location contains the current Lift Pressure in PSIG. Lift Pressure is calculated by subtracting the Evaporator Pressure from the Condenser Pressure. Liquid Injection Solenoid 0216 This location contains the current status of the Liquid Injection Solenoid output. A "0" in this location indicates the output is off. A non zero value indicates the output is on. Liquid Line Refrigerant Temperature - Lo Resolution 0404 This location contains the current Liquid Line Refrigerant Temperature in F. For better resolution of the Liquid Line Refrigerant Temperature, see the following memory location. Liquid Line Refrigerant Temperature - Hi Resolution 041D This is the current Liquid Line Refrigerant Temperature in 0.2 resolution. This location contains a valid value only if the temperature is between 55 F and 106 F. If this location contains a value of 0 or 255, this indicates that the current temperature is out of the 55 to 106 range. If the temperature is out of range for this location, see the above memory location (0404) for an expanded temperature range. Liquid Subcool 0417 This location contains the current Liquid Subcool Temperature in F. This temperature is calculates by subtracting the Liquid Line Temperature from the Condenser Temperature. Load Solenoid 0211 This location contains the status of the Load Solenoid output. A "0" indicates the output is off. A non zero location indicates the output is on. Low Evaporator Pressure Limit This location contains the status of the Low Evaporator Pressure Limit. A "0" indicates that the limiting is inactive. A"1" indicates that limiting is active. Manual Amp Limit 043B 043D Via the keypad/display on the chiller, the operator may enter a "Manual" amp limit for the chiller (See Manual Amp Limit Setpoint below). If the %RLA of the chiller is exceeding the "Manual" amp limit, then capacity limiting will be enforced. This location contains the status of the Manual Amp Limit. A "0" indicates that limiting is inactive. A"1" indicates that limiting is active. Manual Amp Limit Setpoint 0901 This is the "Manual" amp limit setpoint which the operator has set for the chiller via the keypad/display at the chiller. Note this is a EEPROM memory location and should not be written to. If you desire to change the amp limit in response to an MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 28 of 62

algorithm or building demand limit function, use the Network Amp Reset memory location. Maximum Amp Limit 043C If the %RLA of the chiller is exceeding 100%, the chiller capacity will be limited. This location contains the status of "Maximum" Amp Limiting. A "0" indicates that limiting is inactive. A"1" indicates that limiting is active. Motor Control Latch Relay 0213 This location contains the status of the Motor Control Latch output. A "0" indicates the output is off. A non zero value indicates the output is on. Motor Control Relay 021E This location contains the status of the Motor Control Relay (MCR) output. A "0" indicates the MCR output is off. A non zero value indicates the MCR output is on. Motor Current, Amps 0435, 0436 These locations contain the Motor Current in Amps. These locations are read by multiplying the high byte (0435) by 256 and adding the low byte (0436). The result is the Motor Current in Amps (0-65,535). Motor Current, Percent This is the motor amps that the chiller is operating at in percent of Rated Load Amps. Motor Temperature Switch 040C BIT 6 050E This location contains the status of the Motor Temperature Switch. A "0" in BIT 6 (x0xxxxxx) indicates high temperature. A "1" in BIT 6 (x1xxxxxx) indicates normal temperature. Number of Starts 0432, 0433 These locations contain the Number of Starts. These locations are read by multiplying the high byte (0432) by 256 and adding the low byte (0433). The result is the current number of starts. Oil Delta Pressure This location contains the current Oil Delta Pressure in PSID. 040D Oil Feed Temperature 0409 This location contains the current Oil Feed Temperature in F. Oil Gage Pressure 0415 This location contains the current Oil Gage Pressure in PSIG Oil Heater 0215 This location contains the status of the Oil Heater output. A "0" indicates the output is off. A non zero value indicates the output is on. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 29 of 62

Oil Pressure Differential Switch BIT 5 050E This location contains the status of the Oil Pressure Differential Switch. A "0" in BIT 5 (xx0xxxxx) indicates low pressure. A "1" in BIT 5 (xx1xxxxx) indicates normal pressure. Oil Pump 021D This location contains the status of the Oil Pump output. A "0" indicates the output is off. A non zero value indicates the output is on. Oil Sump Temperature This location contains the current Oil Sump Temperature in F. 040A Operating Hours 0430, 0431 These locations contain the current Operating Hours. These locations are read by multiplying the high byte (0430) by 256 and adding the low byte (0431). The result is the current number of starts. Panel Rocker Switch BIT 2 050E This location contains the status of the Panel Rocker Switch. A "0" in BIT 2 (xxxxx0xx) indicates that the switch is set to the "Off" position. A "1" in BIT 2 (xxxxx1xx) indicates that the switch is set to the "Auto" position. Remote Amp Limit 043E This locations contains the current status of Remote Amp Limiting. A "0" indicates that Remote Amp Limiting is not active. A "1" indicates that Remote Amp Limiting is active. Remote Chilled Water Reset 0439 This locations contains the current status of Remote Chilled Water Reset. A "0" indicates that Remote Chilled Water Reset is not active. A "1" indicates that Remote Chilled Water Reset is active. Remote Reset or Amp Limit Signal, 4-20 ma This is a reading of the input signal coming in from a remote device. 040B Remote Start/Stop Switch BIT 3 050F This location contains the Status of the Remote Start/Stop Switch. A "0" in BIT 3 (xxxx0xxx) indicates that the Remote Start/Stop Switch is in the "Stop" position. A "1" in BIT 3 (xxxx1xxx) indicates that the Remote Start/Stop Switch is in the "Start" position. Soft Load Limit This locations contains the current status of Soft Load Limit. A "0" indicates that Soft Load Limit is not active. A "1" indicates that Soft Load Limit is active. Starter Fault Switch 043A BIT 7 050F This location contains the status of the Start Fault Switch. A "0" in BIT 7 (0xxxxxxx) indicates that the Starter Fault Switch is in the "Fault" position. A "1" in BIT 7 (1xxxxxxx) indicates that the Starter Fault Switch is in the "OK" position. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 30 of 62

Starter Transition Switch BIT 4 050F This location contains the status of the Starter Transition Switch. A "0" in BIT 4 (xxx0xxxx) indicates that the Starter Transition Switch is in the "Fault" position. A "1" in BIT 4 (xxx1xxxx) indicates that the Starter Transition Switch is in the "OK" position. Superheat 0416 This location contains the current Superheat Temperature in F. Superheat is calculated by subtracting the Evaporator Temperature from the Suction Temperature. Surge Guard Switch BIT 7 050E This location contain the status of the Surge Guard Switch. A "0" in BIT 7 (0xxxxxxx) indicates that the Surge Guard Switch is in the "Surge" position. A "1" in BIT 1 (1xxxxxxx) indicates that the Surge Guard Switch is in the "OK" position. Unit Status 0424 This is the current unit status of the chiller. The following is a list of possible modes and their corresponding number. Mode Name Start Requested 1 Waiting Low Oil Sump Temperature 2 Evaporator Pump On 3 Waiting for Load 4 Oil Pump On 5 Condenser Pump On 6 Startup Unloading 7 Motor Control Relay Started 8 Running OK 9 Begin Routine Shutdown 10 Begin Rapid Shutdown 11 Waiting High Current 12 MCR Off Post Lubrication 13 Not Used 16 Off: Fault = No Transition 17 Off: Fault = Low Oil Sump Temperature 18 Off: Fault = High Oil Feed to Bearings 19 Temperature Off: Fault = Low Evaporator Pressure 20 Off: Fault = High Discharge Pressure 21 Off: Fault = High Discharge Temperature 22 Off: Fault = Surge 23 Off: Fault = High Suction Temperature 24 Value MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 31 of 62

Mode Name Value Off: Fault = High Motor Temperature 25 Off: Fault = Starter Fault 26 Off: Fault = Low Charge 27 Off: Fault = No Evaporator Flow 28 Off: Fault = No Condenser Flow 29 Off: Fault = Low Delta Oil Pressure 30 Off: Fault = Low Motor Current 31 Off: Fault = Bad Evap Lvg Water Sensor 32 Off: Fault = Bad Evap Ent Water Sensor 33 Off: Fault = Bad Evaporator Temp Sensor 34 Off: Fault = Bad Suction Line Sensor 35 Off: Fault = Bad Liquid Line Sensor 36 Off: Fault = Bad Ent Cond Water Sensor 37 Off: Fault = Bad Lvg Cond Water Sensor 38 Off: Fault = Bad Discharge Line Sensor 39 Off: Fault = Bad Condenser Temp Sensor 40 Off: Fault = Bad Oil Feed Sensor 41 Off: Fault = Bad Oil Sump Sensor 42 Off: Fault = Bad Oil Pres Sensor 45 Off: Vanes Failed Open 46 Off: Load Recycle 48 Off: Time Clock 49 Off: Remote Signal 50 Off: Manual Switch 51 Off: Network Signal 52 Off: Ready to Start 53 Unload Solenoid 0210 This location contains the status of the Unload Solenoid output. A "0" indicates the output is off. A non zero value indicates the output is on. Vanes Closed Switch BIT 2 050F This location contains the status of the Vanes Closed Switch. A "0" in BIT 2 (xxxxx0xx) indicates that the vanes are open. A "1" in BIT 2 (xxxxx1xx) indicates that the vanes are closed. Watchdog Output 0214 This location contains the status of the Watchdog output. A "0" indicates the output is off. A non zero value indicates the output is on. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 32 of 62

Read and Write Memory Locations - Control Processor EEPROM can only be written to 10,000 times. The following is a listing of read and write memory locations for the controls processor of a Series-100 centrifugal chiller. Warning, all 09**,08** and 80** memory locations are EEPROM type and may not be written to more than 10,000 times during the life of the chiller. Precautions should be taken to prevent writing to these memory locations repeatedly. Description Address Range Units Clear Current Fault 042A 0-1 0 = No Action 1 = Clear Fault Comm Port Baud Rate 8010 $B6 or $BB See below Correct Checksum 8001 0-255 Leaving Evaporator 0900 0-255 0.2*X+20= F Temperature Setpoint Maximum Chilled Water 0820 0-75 0.2*X= F Reset Setpoint Network Amp Reset 0450 <20, 20-100 Network Chilled Water 044F <20, 20-100 Reset Network Start/Stop 0451 0, 255 0 = Auto 255 = Routine Shutdown Reset Option 0822 6-11 6 = No Reset 7 = Amp Reset 8 = Amp & Ent 9 = Ent Reset 10 = ChW Reset 11= Amp & ChW Soft Reset 0204 0-255 0 = No Reset 1 = Soft Reset Start Mode 0824 4-5 4 = Local Start 5 = Remote Start Startup Differential 0826 5-50 0.2*X= F Temp. Shutdown Differential Temp. 0827 5-50 0.2*X= F Clear Current Fault 042A If a 1 is written to this memory location, the current fault will be cleared and the controller will be re-initialized. This result is the same as pressing the keypad "Clear Fault" key - the controller will take no action unless the chiller is off. Note: Never write to this memory location without investigating and correcting the cause of the fault. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 33 of 62

Port A Baud Rate Comm Port Baud Rate 8010 The Series-100 centrifugal chiller port A is factory configured to 1200 baud and the memory location will contain the Hex value $B6. To change the baud rate to 9600 baud, change the memory location to $BB. Note that the change will take effect only when the controller is reset (i.e. power reset or soft reset). Also, a change to this memory location will affect the microprocessor's operating system checksum so it is required that the Correct Checksum memory location be changed whenever the Comm Port Baud Rate is changed. Correct Checksum 8001 If Port A baud rate is changed from 1200 baud to 9600 baud, at the same time, read this memory location and add $5, then write the result back into the Correct Checksum memory location. Example, 8010 is changed to $BB. Read this memory location and receive $D3 back. Write $D8 ($D3 +$5) to this memory location 1 to 255 = 20 F to 71 F 0.2 F resolution Leaving Evaporator Temperature Setpoint 0900 This is the desired leaving chilled water temperature setpoint before taking into account any chilled water reset which may be active. Since reset always increases the chilled water setpoint, this memory location contains the lowest chilled water setpoint that the chiller will ever control to. Take the desired chilled water setpoint before reset (to the nearest 0.2 F), subtract 20 and then divide by 0.2. Example: 45 F is the desired setpoint before reset, therefore write (45-20)*5 or 125 to this memory location. Maximum Chilled Water Reset Setpoint 0820 This location contains the maximum amount of Chilled Water Reset. This is the amount of reset that will be done when the hardwired remote reset analog signal is at 20mA or the Network Chilled Water Reset memory location is set to maximum. To interpret this memory location, divide by 5. Example: 50 / 5 = 10.0 F. This location works with Leaving Evaporator Temperature Setpoint to create the Calculated Leaving Evaporator Temperature Setpoint. The Calculated Leaving Evaporator Temperature Setpoint is calculated by adding the reset temperature to the Leaving Evaporator Temperature Setpoint. Example: If the Network Chilled Water Reset is at 50 (Valid range is 20 to 100), and the Maximum Chilled Water Reset Setpoint = 10.0 F, and the Leaving Evaporator Temperature Setpoint = 44.0 F, the amount of reset and final control in F will be: 50-20 = 30 30 / (100-20) =.375.375 * 10.0 F = 3.75 F of reset. The value will be rounded up to 3.8 F because the MicroTech controller only works in increments of 0.2 F. 3.8 F + 44.0 F = 47.8 F = Calculated Leaving Evaporator Temperature Setpoint. Note: For chilled water reset to work, the unit control panel must have the chilled water reset option enabled by using the keypad display to change the "Reset Options" (under Setup Options key) set to "ChW" or "AmpChW" (See I&M 403 MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 34 of 62

page 5 and 31). Alternately, the Reset Option control variable may be set via communications to "ChW". Network Amp Reset 0450 A value of 20 or less will result in no demand limit. A value written from 20 to 100 will linearly reset the maximum %RLA from 100% to 40% RLA. Thus the following chart summarizes the Network Amp Reset: 100% Remote Amp Limit 40% 20 100 Network Amp Reset Note: For network amp reset to work, the unit control panel must have the amp reset option enabled by using the keypad display to change the "Reset Options" (under Setup Options key) set to "Amp" or "AmpChW" (See I&M 403 page 5 and 31). Alternately, the Reset Option control variable may be set via communications to "Amp" reset. Network Chilled Water Reset 044F A value of 20 or less will result in no chilled water reset. A value written from 20 to 100 will linearly reset the chilled water control setpoint from no reset to the Maximum Chilled Water Reset Setpoint. See explanation under Maximum Chilled Water Reset Setpoint for more information. Network command to Stop the chiller Network Start/Stop 0451 Writing a value of 0 to this location enables the chiller for automatic operation. Writing a value of 255 to this memory location will result in a routine shutdown of the chiller. The display on the chiller will show "Off: System Control". Since this is a Ram location, in the event the control panel should loose power (as in a building power failure), the Ram location is cleared and the chiller will initiate a start sequence when power is restored. Thus, we suggest that this Ram location be written to repeatedly (perhaps every minute) to assure the chiller starts and stops as desired. When starting and stopping the chiller via this memory location, it is recommended that the chiller Start Mode be set to "Remote" and that a wire jumper be installed between field terminals 9 and 64 in the control box. Reset Option 0822 This memory location controls which of the possible reset options are enabled. The possible values for this memory location are as follows. MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 35 of 62

Value Description Explanation 6 NoReset No Resets are Enabled 7 Amp Only Amp Reset is Enabled 8 Amp_Ent Amp Reset is Enabled as well as Entering chilled water reset. (see IM 403). 9 Ent Only Entering chilled water reset is enabled. 10 ChW Only Chilled Water Reset is enabled 11 Amp_ChW Both Amp Reset and Chilled water reset are enabled. Soft Reset 0204 If a non-zero value is written to the controller at any time, the controller is reset and will begin initialization. This is a way to reset the controller via communications. Note: Never soft reset the controller unless the compressor and all auxiliary devices are off. Resetting the controller will immediately turn off (fail safe) all outputs. Start Mode 0824 A value of 4 in this memory location designates "Local" control mode, a value of 5 in this memory location designates "Remote". 5 to 50 = 1 F to 10 F 0.2 F resolution 5 to 50 = 1 F to 10 F 0.2 F resolution Startup Differential Temperature 0826 This is the temperature difference above the Leaving Evaporator Setpoint that will start the unit after a standard "cooling load satisfied" shutdown. Take the desired temperature (to the nearest 0.2 F), and multiply by 5. Example: if 7 F is the desired setpoint, write (7*5) or 35 to this memory location. Shutdown Differential Temperature 0827 This is the temperature difference below the Leaving Evaporator Setpoint that will stop the unit after a standard "cooling load satisfied" shutdown. Take the desired temperature (to the nearest 0.2 F), and multiply by 5. Example: if 4 F is the desired setpoint, write (4*5) or 20 to this memory location. Keypad/Display Controller Addresses There is a separate microprocessor controller board that is used for the Keypad/Display. This microprocessor is a level 2 controller while the chiller controller is a slave (level 3) to the keypad/display. To read memory locations from the display processor, use a different address. The proper addressing for the keypad/display processor is: "ll" "ss" Chiller No. 1 01 00 Chiller No. 2 02 00 MicroTech Series 100 Centrif. Chiller Open Protocol Version 3.2 Variables 36 of 62