McQuay AGZ 010BS Installation, Operation And Maintenance Manual
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McQuay AGZ 010BS Installation, Operation And Maintenance Manual

Air-cooled scroll compressor water chillers
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Installation, Operation and Maintenance Manual
Air-Cooled Scroll Compressor Water Chillers
AGZ 010BS – AGZ 034BS, Packaged Chiller
AGZ 010BM – AGZ 034BM, Remote Evaporator
10 to 34 Tons, 35 to 120 kW
R-22, R-407C
60 Hertz
Software Version AGZSU0102D
IOMM AGZB1
Group: Chiller
Part Number: 331975001
Effective: October 2007
Supersedes: New

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Summary of Contents for McQuay AGZ 010BS

  • Page 1 Group: Chiller Part Number: 331975001 Effective: October 2007 Supersedes: New Air-Cooled Scroll Compressor Water Chillers AGZ 010BS – AGZ 034BS, Packaged Chiller AGZ 010BM – AGZ 034BM, Remote Evaporator 10 to 34 Tons, 35 to 120 kW R-22, R-407C 60 Hertz...

  • Page 2: Table Of Contents

    General ............32 ©2007 McQuay International. Illustrations and data cover the McQuay International product at the time of publication and we reserve the right to make changes in design and construction at anytime without notice. ™® The following are trademarks or registered trademarks of their respective companies: BACnet from ASHRAE;...

  • Page 3: Introduction

    Units are shipped FOB factory and McQuay is not responsible for physical damage after unit leaves the factory. Note: Unit shipping and operating weights are listed on pages 16 and 17.

  • Page 4: Location

    Figure 1, Suggested Pushing Arrangement BLOCKING REQUIRED ACROSS FULL WIDTH Figure 2, Suggested Lifting Arrangement SPREADER BAR (2) NOTE:: The fork lift slots can be used for lifting by inserting sufficiently strong pipe through them as shown in Figure 2. Use the outboard slots on three-fan units and the only two on two-fan units.
  • Page 5 The fan deck with the condenser fans and motors can be removed from the top of the unit. Clearances Figure 3, Clearance requirements The flow of air to and from the condenser coil must not be limited. 4 Ft. (1220mm) Restricting airflow or allowing air Clearance for Air Inlet recirculation will result in a decrease in...

  • Page 6: Vibration Isolators

    Vibration Isolators Vibration isolators are recommended for all roof-mounted installations or wherever vibration transmission is a consideration. The unit should be initially placed on shims or blocks at the listed free height. When all piping, wiring, flushing, charging, etc. is completed, the springs are adjusted upward to loosen the blocks or shims that are then removed.

  • Page 7: Chilled Water System

    Chilled Water System Water Piping Local authorities can supply the installer with the proper building and safety codes required for proper installation. Install piping with minimum bends and changes in elevation to minimize pressure drop. Consider the following when installing water piping: 1.
  • Page 8 Mount a water flow switch in the leaving water line to shut down the unit when water flow is interrupted. Figure 5, Flow Switch Installation A flow switch is available from McQuay (part number 017503300). It is a “paddle” type switch and adaptable to pipe sizes down to 1 1/4” (32mm) nominal. Certain minimum flow rates are required to close the switch and are listed in Table 2.

  • Page 9: Water Connections

    condition exists. Freeze protect any flow switch that is installed outdoors. Follow installation instructions provided with the flow switch. Calibrate the flow switch to open at one-half of nominal flow rate. NOTE: Differential pressure switches are not recommended for outdoor installation.

  • Page 10: Glycol Solutions

    Glycol Solutions The use of glycol antifreeze solutions will decrease unit capacity and increase the pressure drop through the cooler. See Product Manual Catalog ACZAGZB1 for specific ratings and correction factors. CAUTION Do not use automotive grade antifreeze. Industrial grade glycols must be used. Automotive antifreeze contains inhibitors that will cause plating on the copper tubes within the chiller evaporator.
  • Page 11 Figure 6, Evaporator Water Pressure Drop Curves AGZ 010 AGZ 020 AGZ 025 AGZ 029 AGZ 034 AGZ 017 AGZ 013 Minimum Flow Nominal Flow Maximum Flow Pressure Pressure Pressure Flow Rate Flow Rate Flow Rate Model Drop Drop Drop 15.0 24.0 17.3...

  • Page 12: R-407C Units

    R-407C Units AGZ chillers are available with R-407C refrigerant as non-ARI certified units. R-407C is a zeotropic blend of three compounds, and as such exhibits the characteristic of glide. It does not behave as one substance like R-22 does. Glide is the difference (in degrees F) between the beginning and end phase-change process in either the evaporator or condenser.
  • Page 13 Start the system and observe operation. Use standard charging procedures (liquid only) to top off the charge. It may be necessary to add refrigerant through the compressor suction. Because the refrigerant leaving the cylinder must be a liquid, exercise care to avoid damage to the compressor.

  • Page 14: Control Layout And Operation

    Control Layout and Operation Control Center All electrical controls are enclosed in a weatherproof control center with tool-locked, hinged access doors. The left-hand section contains the microprocessor controller and control input and output terminals. All high-voltage components are located on the right side of the panel. 24-Volt Trans.

  • Page 15: Sequence Of Operation

    C). 6. After system performance has stabilized, complete the current AGZ Start-Up Form (obtainable from the local McQuay sales office) to establish inception of warranty benefits. Return the form to McQuay International through your sales representative. Sequence of Operation...

  • Page 16: Physical Data

    Physical Data AGZ-BS, R-22/R-407C Table 4, Physical Data, AGZ 010BS through 017BS, Packaged, R-22/R-407C AGZ MODEL NUMBER PHYSICAL DATA 010B 013B 017B BASIC DATA Unit Capacity @ ARI Conditions (1), Tons (kW) 10.0 (36.2) 13.7 (48.2) 15.8 (55.6) Number Of Refrigerant Circuits Unit Operating Charge, R-22 and R-407C, Lb.
  • Page 17 Table 5, Physical Data, AGZ 020BS through 034BS, Packaged, R-22/R-407c AGZ MODEL NUMBER PHYSICAL DATA 020B 025B 029B 034B BASIC DATA Unit Capacity @ ARI Conditions (1), Tons (kW) 20.6 (72.4) 22.7 (79.8) 27.7 (97.5) 34.0 (119.5) Number Of Refrigerant Circuits 34.0 (15.4) Unit Operating Charge, R-22 and [R-407C], 42.0 (19.1)

  • Page 18: Agz-Bm, R-22/R-407C

    AGZ-BM, R-22/R-407C Table 6, Physical Data, AGZ 010BM through 017BM, Remote Evaporator, R-22/R-407C AGZ MODEL NUMBER PHYSICAL DATA 010B 013B 017B BASIC DATA Unit Capacity @ ARI Conditions (1), Tons (kW) 10.0 (36.2) 13.7 (48.2) 15.8 (55.6) Number Of Refrigerant Circuits Unit Operating Charge, R-22 and[R-407C, Lb.
  • Page 19 Table 7, Physical Data, AGZ 020BM through 034BmS, Remote Evaporator, R-22/R-407c AGZ MODEL NUMBER PHYSICAL DATA 020B 025B 029B 034B BASIC DATA Unit Capacity @ ARI Conditions (1), Tons (kW) 20.6 (72.4) 22.7 (79.8) 27.7 (97.5) 34.0 (119.5) Number Of Refrigerant Circuits 34.0 (15.4) Unit Operating Charge, R-22 and [R-407C], 42.0 (19.1)

  • Page 20: Electrical Data

    Electrical Data Field Wiring Wiring must comply with all applicable codes and ordinances. Warranty is void if wiring is not in accordance with specifications. Copper wire is required for all power lead terminations at the unit. AGZ 010A through AGZ 034A units have single point power connection. A single field supplied fused disconnect is required.
  • Page 21 Table 9, Compressor and Condenser Fan Motor Amp Draw, R-22 Rated Load Amps Locked Rotor Amps Compressors Compressors No. of Volts Unit Fans Motor Motor Across-The-Line No. 1 No. 2 Size (Each) (Each) No. 1 No. 2 19.4 19.4 21.4 18.6 18.6 23.7...
  • Page 22 Table 10, Field Wiring Data, R-22 Wiring to Wiring to Wiring to High Interrupt Standard Power Block Terminal Optional Disconnect Switch or HSCCR Circuit Breaker Volts Unit Connector Wire Connector Wire Connector Wire Maximum Disconnect Max. Size Range Range Range Terminal Amps Size Amps...
  • Page 23 R-407C Table 11, Electrical Data, R-407C Power Supply Field Fuse Minimum Hub (Conduit or Breaker Size Field Wire Circuit Connection) Unit Volts Ampacity Wire Nominal Size (MCA) Quantity Gauge Quantity Size Recommended Maximum In. (mm) 6 AWG 1.00 (25) 6 AWG 1.00 (25) 010B 10 AWG...
  • Page 24 Table 12, AGZ 010 034A, Compressor & Fan Motor Amps, R-407C Rated Load Amps Locked Rotor Amps F.L. Amps Compressors Compressors No. of Volts Unit Fans Across-The-Line Motor Motor No. 1 No. 2 Size (Each) No. 1 No. 2 (Each) 21.4 20.3 20.3...
  • Page 25 Table 13, Field Wiring Data, R-407C Wiring to Wiring to Wiring to High Interrupt Standard Power Block Terminal Optional Disconnect Switch or HSCCR Circuit Breaker Volts Unit Connector Wire Connector Wire Connector Wire Maximum Disconnect Max. Size Range Range Range Terminal Amps Size Amps...
  • Page 26 Notes for Electrical Data 1. Unit wire size ampacity (MCA) is equal to 125% of the largest compressor-motor RLA plus 100% of RLA of all other loads in the circuit. 2. The control transformer is furnished and no separate 115V power supply is required. 3.
  • Page 27 Figure 7, AGZ 010A through AGZ 034A, Typical Field Wiring Diagram UNIT MAIN DISCONNECT GND LUG TERMINAL (BY OTHERS) BLOCK 3 PHASE TO COMPRESSOR(S) POWER AND FAN MOTORS SUPPLY NOTE: ALL FIELD WIRING FUSED CONTROL TO BE INSTALLED AS NEC CIRCUIT CLASS 1 WIRING SYSTEM TRANSFORMER...

  • Page 28: Dimensions & Weights

    Dimensions & Weights Figure 8, AGZ 010BS - 017BS, Packaged (See page 30 for additional dimensions and weights) 3.00 QTY.2 EVAP. INLET ACCESS PANEL 31.70 11.27 EVAP. 14.66 OUTLET CONTROL BOX ACCESS DOORS 5.17 .875 POWER ENTRY KNOCKOUT (OTHER SIDE) POWER 2.61...
  • Page 29 Figure 10, AGZ 010 - 017BM Remote Evap. (See page 30 for additional dimensions and weights NOTE: ACCESS L2 & L4 ARE LOCATED ON PANEL OPPOSITE SIDE OF UNIT. ALL WEIGHTS ARE IN POUNDS. .875 CONTROL BOX POWER ENTRY 5.17 ACCESS DOORS KNOCKOUT (OTHER SIDE)

  • Page 30: Remote Evaporators

    Remote Evaporators Figure 12, Remote Evaporators, for AGZ 010BM – 034BM Suction Inlet 30.2 Temp Sensor (767) Liquid Outlet 8.2 (208) (30) (30) 10.2 (260) (90) (90) Victaulic Dimension Liquid Line Conn. Suction Line Conn. Temp. Sensor Water Conn. “A” Model Brazed, in (L).

  • Page 31: Acz/Agz Dimensions And Weights

    ACZ/AGZ Dimensions and Weights Table 14, Packaged Chiller, Dimensions and Weights CENTER OF GRAVITY LIFTING CORNER EVAP. MOUNTING CORNER (IN.) SHIP WT. OPN. WT. WEIGHTS (LBS) CONN. WEIGHTS (LBS.) UNIT (LBS) (LBS) (IN.) SIZE VICTAULIC 010B 28.00 21.50 23.40 1085 1095 013B 27.40...

  • Page 32: System Maintenance

    System Maintenance General On initial start-up and periodically during operation, it will be necessary to perform certain routine service checks. Among these are taking electric leg readings. Some readings are readily available on the MicroTech II controller’s display. Lubrication No routine lubrication is required on the AGZ units. The fan motor bearings are of the permanently lubricated type and require no lubrication.

  • Page 33: Standard Microtech Ii Controller

    Standard MicroTech II Controller Table of Contents Overview ................34 General Description .............34 Compressor Motor Description ........34 FanTrol Head Pressure Control ........34 Inputs/Outputs ..............35 Setpoints ................35 Equipment Protection Alarms .........37 Control Functions and Definitions ........39 Limit Alarms ..............39 Control Functions ............39 Unit Enable ..............41 Unit Mode Selection ............41 Unit State ...............42...

  • Page 34: Overview

    Overview The MicroTech II controller’s state-of-the-art design will not only permit the chiller to run more efficiently, but will also simplify troubleshooting if a system failure occurs. Every MicroTech II controller is programmed and tested prior to shipment to contribute to a trouble-free start-up.

  • Page 35: Inputs/Outputs

    Inputs/Outputs Table 18, Inputs and Outputs Analog Inputs Description Signal Source Range 0 to10 degrees Reset of Leaving Water Temperature 4-20 mA Current 60°F max inlet Evaporator Refrigerant Pressure 0.5 to 4.5 VDC (NOTE 1) 0 to 132 psi Condenser Refrigerant Pressure 0.5 to 4.5 VDC (NOTE 1) 3.6 to 410 psi Leaving Evaporator Water Temperature...
  • Page 36 Table 19, Setpoints Description Default Range Unit Unit Enable OFF, ON COOL COOL w/Glycol Unit Mode COOL ICE w/Glycol TEST SWITCHES, KEYPAD, Control Source SWITCHES NETWORK COOL COOL w/GLYCOL Available Modes COOL COOL/ICE w/GLYCOL TEST Display Units °F/psi °F/psi Language ENGLISH ENGLISH, Cool LWT...
  • Page 37 Description Default Range Stage #2 Off 180 psi 150 to 200 psi Stage #3 Off 190 psi 150 to 200 psi Sensor Offsets Evaporator Refrig Press Sensor Offset 00.0 psi -20.0 to 20.0 psi Condenser Refrig Press Sensor Offset 00.0 psi -20.0 to 20.0 psi Leaving Evaporator Water Temp Sensor 0.0 °F...

  • Page 38: Setpoint Security

    Setpoint Security All setpoints are protected by using passwords. Two four-digit passwords provide OPERATOR and/or MANAGER levels of access to changeable parameters. Once a password has been entered, it remains valid for 15 minutes after the last key-press on the unit controller.

  • Page 39: Control Functions And Definitions

    Events (Limit Alarms) The following events limit the operation of the chiller in some way as described in the Action Taken column. These alarms are auto-clearing based on reaching the conditions in the reset column. Table 21, Events (Limit Alarms) Description Occurs When: Action Taken...
  • Page 40 Every 12 seconds, the current LWT is subtracted from the value 12 seconds back. This value is added to a buffer containing values calculated at the last five intervals. The final result is a slope value that is an average over the past 60 seconds. Pulldown Rate The slope value calculated above will be a negative value as the water temperature is dropping.

  • Page 41: Unit Enable

    Pumpdown Pressure The pressure to which a circuit will pumpdown is based on the Low Evaporator Pressure Unload setpoint. The equation is as follows: Pumpdown pressure = Low evap pressure unload – 15 psi , with the calculated value limited to a minimum of 10 psi. Unit Enable Enabling and disabling the chiller is controlled by the Unit Enable Setpoint with options of OFF and ON.

  • Page 42: Power Up Start Delay

    Unit Test Mode The unit test mode allows manual testing of controller outputs. Entering this mode requires the following conditions. • Unit Switch = OFF • Manager password active. • Available Unit Mode setpoint = TEST A test menu can then be selected to allow activation of the outputs. It is possible to switch each digital output ON or OFF and set the analog outputs to any value.

  • Page 43: Evaporator Water Pump State Control

    Figure 13, Unit State Diagram Unit State Diagram Power On Pumpdown Auto Evaporator Water Pump State Control Operation of the evaporator pump is controlled by the state-transition diagram shown below. Figure 14, Evaporator Pump State Evaporator Pump States Power ON START See transition code on following page.

  • Page 44: Condenser Fans

    Transitions: T1 – Transition from Off to Start Requires any of the following • Unit state = Auto • LWT < Freeze setpoint - 1 T2 – Transition from Start to Run • Flow ok for time > evaporator recirculate time T3 –...

  • Page 45: Maximum Lwt Rate

    If the evaporator pressure drops below the Low Evaporator Pressure Unload setpoint, the Low Evaporator Pressure Unload event is triggered. This can only occur when both compressors are running. When triggered, one compressor is shut off. These events are logged to an event log when they occur. Both remain active until the evaporator pressure rises 5 psi above the hold setpoint or both compressors are off.
  • Page 46 ALSO If Unit Mode = Cool, AND At least one compressor is running, AND LWT error > Upper Control Band, AND Pulldown rate <= Max pulldown rate, AND Compressors running < unit capacity limit, AND Stage up timer is expired, THEN Stage Up Now = True ALSO If Unit Mode = Ice, AND...
  • Page 47 In the event of a tie on number of starts, the lower numbered compressor will start first. In the event of a tie on run-hours, the lower numbered compressor will shut off first. Run hours are compared in terms of tens of hours. Next On = 1 if compressor 1 starts <= compressor 2 starts or compressor 2 not available, and compressor 1 available Next On = 2 if compressor 1 starts >...

  • Page 48: Using The Controller

    Liquid Line Solenoid The liquid line output shall be on any time a compressor is running and the unit is not performing a pumpdown. This output should be off at all other times. Using the Controller 4x20 Display & Keypad The 4-line by 20-character/line liquid crystal display and 6-key keypad are shown below.

  • Page 49: Menu Screens

    MENU Key The MENU key is used to switch between the shortcut method (known as the MENU mode and as shown in Figure 15) and scrolling method (known as the SCROLL mode). The MENU mode is the shortcut to specific groups of menus used for checking ALARMS, for VIEWING information, or to SET setpoint values.
  • Page 50 When the change has been made, press the ENTER key to enter it. No setting is changed until the ENTER key is pressed. For example, to change the chilled water setpoint: 1. Press MENU key to go to the MENU mode (see Figure 15). 2.

  • Page 51: Menu Matrix

    Figure 17, Menu Matrix "MENU" "VIEW" MENUS UNIT COMP REFRIGERANT FANS VIEW UNIT VIEW UNIT VIEW COMP #1 VIEW COMP #2 VIEW EVAP/COND PRESS (1) VIEW FAN STATUS 1-3 TEMP 1-3 STATUS STATUS STAGING VIEW EVAP APPROACH (2) ⇐ Continued ⇐ (Right side of matrix continued from above) "ALARM"...

  • Page 52: View Screens Defined

    Menu selection is initiated by pressing the MENU key that changes the display from a regular data screen to a menu screen. Menu selections are then made using the arrow keys according to labels on the right side of the display (the arrows are ignored). When the last menu item is selected, the display changes to the selected data screen.
  • Page 53 Unit states can be: Auto Off:Ice Mode Timer Off:All Comps Disabled Off:Unit Alarm Off:Keypad Disable Off:Remote Switch Off:BAS Disable Off:Unit Switch Auto:High LWT Pulldn Auto:Cycle Timers Auto:Wait for load Auto:OAT Lockout Auto:Evap Recirc Auto:Wait for flow Auto:Pumpdown Auto:Evap Press Low Auto:Cond Press High Off:Test Mode as determined from the Unit State variable, the Unit Mode setpoint, the Unit Enable and the...

  • Page 54: Alarm Screens Defined

    VIEW COMP#1 Hours = XXXXX Starts = XXXXX Above two screens duplicated for compressor #2. VIEW REFRIGERANT VIEW REFRIG EVAP Press = XX.Xpsi COND Press - XX.Xpsi With R22 Refrigerant With R407C Refrigerant VIEW REFRIG VIEW REFRIG SAT EVAP = XXX.X°...

  • Page 55: Set Screens Defined

    ALARM LOG (1) High Condenser Press hh:mm:ss d/mmm/yyyy The last 25 alarms, either shutdown or limit, are shown in this menu with subsequent menus stored under it. ARROW DOWN from this menu will go to the next-to-last alarm, ARROW DOWN again will go to the second from last, and so on through the last 25 occurrences. The screens are numbered (1), (2), (3), etc.
  • Page 56 SET UNIT SPs Available Modes =COOL w/Glycol Set w/ FP Switch Off Available Modes settings can be COOL, COOL w/Glycol, ICE w/Glycol, or TEST as selected from the available modes imbedded in the menu. The 4 line is a reminder that the ON/OFF switch on the front panel (FP) must be in the OFF position before the MODE can be changed.
  • Page 57 SET UNIT SPs CLOCK dd/mmm/yyyy hh:mm:ss SET UNIT SPs (8) Units = ° ° ° ° F/psi Lang = ENGLISH Refrig = Select Type Units settings are only °F/psi at the present time. °C/kPa will be available later. Lang (Language) settings can be only ENGLISH at present. Refrig (Refrigerant) selection is done at the factory prior to shippment.
  • Page 58 SET UNIT SPs (14) ENTER PASSWORD XXXX Active Password Level:None Two four-digit passwords provide OPERATOR and MANAGER levels of access to changeable parameters. The passwords are preprogrammed into the controller. Operator Password is 0100. Either password must be entered using the ENTER PASSWORD (12) screen before a protected setting can be changed.
  • Page 59 The LowEvPrHold and LowEvPrUnld have the same default value of 59 psi. If two compressors are running, the LowEvPrUnld is in effect and the lag compressor will be shut off to unload the unit. If one compressor is running, the LowEvPrHold is in effect and the lag compressor is prevented from starting, thereby holding the unit capacity.
  • Page 60 Speedtrol tells the controller whether the optional SpeedTrol is installed in the unit. The UP ARROW toggles between YES and NO. The setting changes the range available: YES = 35°F to 60°F, with 35°F being the recommended setting; NO = -2°F to 60°F, with 0°F being the recommended setting.

  • Page 61: Bas Interface

    If an interface module was ordered, one of the following BAS interface installation manuals was shipped with the equipment. Additional copies of referenced McQuay documents may be obtained from the local McQuay sales office, from the local McQuay Factory Service office, from the McQuay Technical Response Center, located in Staunton, Virginia (540-248-0711) or downloaded from www,mcquay.com.

  • Page 62: Service

    Service WARNING Disconnect and tag out all power sources to the unit before doing any service inside the unit. Failure to do so can cause severe personal injury or death. CAUTION Service on this equipment is to be performed by qualified service personnel with special regard to regulations concerning release of refrigerant to the atmosphere.

  • Page 63: Optional Controls

    Optional Controls SpeedTrol Head Pressure Control The SpeedTrol method of head pressure control operates in conjunction with FanTrol by modulating the motor speed on system #1 fan in response to condenser pressure. By reducing the speed of the last fan as the condensing pressure falls, the unit can operate to 0°F (-18°C) ambient air temperature.
  • Page 64 WARNING The hot gas line may become hot enough to cause injury in a very short time. Avoid contact during valve checkout. On installations where the condensing unit is remote from the evaporator, it is recommended that the hot gas bypass valve be mounted near the condensing unit to minimize the amount of refrigerant that will condense in the hot gas line during periods when hot gas bypass is not required.
  • Page 65 The valve is adjusted using the adjusting screw show in the drawing. The range is 0 to 100 psi with about 16 psi change for one turn of the screw. Turning clockwise will increase the valve setting. The load must be varied to properly set these valves. The load should be decreased so that the suction pressure decreases.

  • Page 66: Troubleshooting Chart

    Troubleshooting Chart WARNING Troubleshooting can present risks of severe personal injury or death from burns, cuts, electrocution, strangulation and asphyxiation. Troubleshooting must be done by trained, experienced technicians only. Table 22, Troubleshooting Chart PROBLEM POSSIBLE CAUSES POSSIBLE CORRECTIVE STEPS 1. Main switch open 1.
  • Page 68 All McQuay equipment is sold pursuant to McQuay’s Standard Terms and Conditions of Sale and Limited Product Warranty. This document contains the most current product information as of this printing. For the most up-to-date product information, please go to www.mcquay.com 800 432 1342•...

This manual is also suitable for:

Agz 034bsAgz 034bmAgz 010bm

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