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Related Manuals for McQuay ACZ 010A
Summary of Contents for McQuay ACZ 010A
- Page 1 Installation, Operation and Maintenance Manual IOMM ACZ1 Group: Chiller Part Number: 330262002 Effective: December 2001 Supersedes: New Air-Cooled Scroll Condensing Units ACZ 010A – ACZ 039A 10 to 43 Tons, 35 to 150 kW R-22, 60 Hertz...
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Page 2: Table Of Contents
"McQuay" is a registered trademark of McQuay International 2001 McQuay International "Illustrations and data cover the McQuay International products at the time of publication and we reserve the right to make changes in design and construction at anytime without notice" ACZ 010A through 039A... -
Page 3: Introduction
Check the unit nameplate before unloading to be sure it agrees with the power supply available. Units are shipped FOB factory and McQuay is not responsible for physical damage after the unit leaves the factory. -
Page 4: Location
Most operational, equipment protection, and starting controls are located in the unit control box. The fan deck with the condenser fans and motors can be removed from the top of the unit. ACZ 010A through 039A IOMM ACZ1... - Page 5 The minimum clearance to a side wall or building taller than the unit height is 6 feet (1828mm) provided no solid wall above 6 feet (1828mm) tall is closer than 12 feet (3658mm) to the opposite side of the unit. IOMM ACZ1 ACZ 010A through 039A...
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Page 6: Vibration Isolators
Vibration Isolators Vibration isolators are recommended for all roof-mounted installations or wherever vibration transmission is a consideration. The isolators can be purchased from McQuay by the part numbers shown in the table. The unit should be initially on shims or blocks at the listed free height. When all piping, wiring, flushing, charging, etc. - Page 7 If the water volume is too low, operational problems can occur, including rapid compressor cycling, rapid loading and unloading of compressors, erratic refrigerant flow in the chiller, improper motor cooling, shortened equipment life and other undesirable occurrences. IOMM ACZ1 ACZ 010A through 039A...
- Page 8 Figure 5, Flow Switch Installation flow is interrupted. 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.
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Page 9: Refrigerant Piping
Suction Lines McQuay recommends the use of ASHRAE for guidelines in sizing and routing piping with one exception. See the 1998 ASHRAE Handbook Refrigeration Edition, Chapter 2 for tables and guidelines. - Page 10 Long Vertical Riser Installation Where job conditions require refrigerant gas lifts of more than 25 feet, McQuay recommends the installation of a short trap half-way up the riser or at not more than 20 feet intervals. These traps are required to capture and hold small quantities of oil during off cycles.
- Page 11 3.05 psi with R-22, the liquid line and its refrigerant specialties can have pressure losses totaling 10 x 3.05 psi (or 10 x 2.2) and still satisfy the objective of delivering pure liquid to the expansion valve. IOMM ACZ1 ACZ 010A through 039A...
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Page 12: Unit Component Location
Unit Component Location Control Panel Tandem Scroll Compressors Charging Valve Evaporator Solenoid Valve, Expansion Valve Filter Drier Optional Hot Gas Bypass Valve ACZ 010A through 039A IOMM ACZ1... -
Page 13: Control Layout And Operation
Verify superheat temperature is at the factory setting of 8 to 12 degrees F (4.4 to 6.7 degrees C). After system performance has stabilized, complete the current ACZ 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. -
Page 14: Sequence Of Operation
Sequence of Operation The following sequence of operation is typical for Models ACZ 010A through ACZ 039A. It can vary depending upon options. Start-Up With the control circuit power on, 115V power is applied through the control circuit fuse F1 to the compressor crankcase heaters, the compressor motor protections and the primary of the 24V control circuit transformer. -
Page 15: Physical Data
Physical Data Table 3, Physical Data, ACZ 010A through 020A ACZ MODEL NUMBER PHYSICAL DATA 010A 013A 016A 020A BASIC DATA Number Of Refrigerant Circuits Unit Operating Charge, R-22, Lb. (kg), Note 1 22.0 (10.0) 22.0 (10.0) 24.0 (10.9) 31.0 (14.1) Cabinet Dimensions, LxWxH, In. - Page 16 1140 Total Unit Airflow, CFM (l/s), 60 Hz 20925 (9877) 20925 (9877) 19800 (9346) 19800 (9346) Note 1: Operating charge is for the condensing unit only. Refrigerant lines and evaporator charge must be added. ACZ 010A through 039A IOMM ACZ1...
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Page 17: Electrical Data
Copper wire is required for all power lead terminations at the unit. ACZ 010A through ACZ 039A units have single-point power connection. A single field supplied fused disconnect is required or it can be supplied as a factory-mounted option. The control transformer is factory mounted. - Page 18 Table 6, ACZ 010A – 039A Compressor and Condenser Fan Motor Amp Draw Rated Load Amps Locked Rotor Amps No. of Compressors Compressors Unit Volts Motor Motor Across-The-Line Size Mtrs No. 1 No. 2 (Each) (Each) No. 1 No. 2 13.5...
- Page 19 Table 7, ACZ 010A – 039A Field Wiring Data, Single Point Power Wiring to Wiring to Standard Power Block Terminal Optional Disconnect Switch UNIT Volts Connector Wire Maximum Connector Wire Range Disconnect SIZE Range Terminal Amps (Copper Wire Only) Size (Copper Wire Only) 14 GA –...
- Page 20 This power must be fused. All field wiring to unit power block or non-fused disconnect switch must be copper. All field wire size values given in table apply to 75°C rated wire per NEC. ACZ 010A through 039A IOMM ACZ1...
- Page 21 Figure 7, ACZ 010A through 039A, Typical Field Wiring Diagram DISCONNECT UNIT MAIN GND LUG (BY OTHERS OR TERMINAL BLOCK FACTORY OPTION) 3 PHASE TO COMPRESSOR(S) POWER AND FAN MOTORS SUPPLY FUSED CONTROL CIRCUIT TRANSFORMER 120 VAC DISCONNECT TB1-20 (BY OTHERS)
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Page 22: Dimensional Data
Dimensional Data Figure 8, ACZ 010A through 020A 46.27 (1175.26) POWER ENTRY KNOCKOUT (OTHER SIDE) POWER ENTRY CONTROL PANEL CONTROL ACCESS DOORS ELECTRICAL 51.0 KNOCKOUT (1295.40) SUCTION INLET ACCESS DOOR HOT GAS BYPASS LIQUID OUTLET 31.11 (790.19) 21.32 7.55 MOUNTING (541.53) -
Page 23: System Maintenance
The sightglass indicates what moisture condition corresponds to a given element color. If the sightglass does not indicate a dry condition after about 12 hours of operation, the refrigerant and oil should be tested for moisture. IOMM ACZ1 ACZ 010A through 039A... -
Page 24: Standard Microtech Ii Controller
Automatic Adjusted Range Limits ........29 Compressor Staging Parameters ........29 Using the Controller ............31 Display and Keyboard.............31 Getting Started..............31 Menu Screens ..............32 Menu Matrix ..............34 View Screens Defined.............35 Alarm Screens Defined ...........37 Set Screens Defined............37 ACZ 010A through 039A IOMM ACZ1... -
Page 25: Overview
On 150 psig, Off with unit Stage #2 On 290 psig, Off 170 psig On 290 psig, Off 170 psig Stage #3 On 310 psig, Off 180 psig Note: Fan #1 is on with first compressor above 75°F (24°C). IOMM ACZ1 ACZ 010A through 039A... -
Page 26: Inputs/Outputs
The PW (password) column indicates the password level that must be entered in order to change the setpoint. Passwords are as follows: O = Operator [0100] M = Manager, M level settings are not normally changed for chilled water air-conditioning applications. ACZ 010A through 039A IOMM ACZ1... -
Page 27: Equipment Protection Alarms
If the alarm is auto-clearing, the reset condition is shown below. Otherwise, the alarm is manually reset, requiring the operator to clear the alarm. IOMM ACZ1 ACZ 010A through 039A... -
Page 28: Limit Alarms
Table 13, Unit Enable Conditions Unit Off Control Source Remote Input Keypad Entry BAS Request Enable Input Set Point SWITCHES SWITCHES KEYPAD KEYPAD NETWORK NETWORK NETWORK NOTE: An “x” indicates that the value is ignored ACZ 010A through 039A IOMM ACZ1... -
Page 29: Unit Mode Selection
Automatic Adjusted Limits The following setpoint ranges will be adjusted automatically based on selected options or mode of operation. Low Ambient Lockout Temperature SpeedTrol Range SpeedTrol = N 35– 60°F SpeedTrol = Y -2 – 60°F IOMM ACZ1 ACZ 010A through 039A... - Page 30 This output is ON when the Compressors are ON. It is OFF for all other cases. Fan #1, #2, & #3 – (Terminals J13 – NO6, J14 – NO7, J15 – NO8) Condenser Fans Staging is based on Condenser pressure as selected Fan Stage On & Off setpoints. ACZ 010A through 039A IOMM ACZ1...
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Page 31: Using The Controller
ALARM, VIEW, and SET as shown in Figure 10. This corresponds to the second row of screens on Figure 12. One of these groups of screens can then be selected by pressing the key connected to it via the pathway shown in Figure 10. IOMM ACZ1 ACZ 010A through 039A... -
Page 32: Menu Screens
DOWN key Decrement decreases the value of a setting. These four edit functions are indicated by one-character abbreviation on the right side of the display (this mode is entered by pressing the ENTER key). ACZ 010A through 039A IOMM ACZ1... - Page 33 1. Change another setpoint in this menu by scrolling to it with the ENTER key 2. Using the ENTER key, scroll to the first line in the menu. From there the ARROW keys can be used to scroll to different menus. IOMM ACZ1 ACZ 010A through 039A...
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Page 34: Menu Matrix
(the arrows are ignored). When the last menu item is selected, the display changes to the selected data screen. An example follows showing the selection of the “VIEW REFRIGERANT” screen. ACZ 010A through 039A IOMM ACZ1... -
Page 35: View Screens Defined
Unit status can be OFF, AUTO, and ALARM as determined from the Unit State variable, the Unit Mode setpoint, the Unit Enable and the presence of an alarm. Compressor states can be OFF/OFF, ON/OFF, OFF/ON, and ON/ON. IOMM ACZ1 ACZ 010A through 039A... - Page 36 = OFF Hours = XXXXX Starts = XXXXX VIEW REFRIGERANT VIEW REFRIG ° ° ° ° F SAT EVAP XXX.X XX.X SAT COND XXX.X XX.X VIEW FANS VIEW FANS Stages ON = 2 of 3 ACZ 010A through 039A IOMM ACZ1...
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Page 37: Alarm Screens Defined
If a word type setpoint (for example, YES or NO) is to be selected, the choices are loaded into the menu and selected by scrolling through the available setpoint options using the UP ARROW key. Enter the desired value or word into the controller by pressing the SET key. IOMM ACZ1 ACZ 010A through 039A... - Page 38 Unit settings are only °F/psi at the present time. °C/kPa will be available later. Lang (Language) settings can be only ENGLISH at present. SET UNIT SPs (5) Protocol = NONE Ident Number=001 Baud Rate=9600 Protocol selection for BAS will be available in June 2002. ACZ 010A through 039A IOMM ACZ1...
- Page 39 This menu sets the anti-recycle timers. Stop-Start is the time required before starting a compressor after it has stopped. Start-Start is the time required before starting a compressor after the last time it has started. It is recommended that these default values not be changed. IOMM ACZ1 ACZ 010A through 039A...
- Page 40 The default setting is 380 psi. The HiCondStDn is a limit alarm that unloads the unit in an attempt to prevent total shutdown from the HighCondPr. The stage down is set at 370 psi. ACZ 010A through 039A IOMM ACZ1...
- Page 41 The default values are shown in the boxes. These settings are used with both FanTrol and SpeedTrol. SpeedTrol takes effect when the last fan is running after FanTrol cycles off the others. IOMM ACZ1 ACZ 010A through 039A...
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Page 42: Service
Liquid Line Solenoid The field installed liquid line solenoid valve does not normally require any maintenance. Reliable operation of the solinoid valve is necessary for the pump-down function of the unit's control system. ACZ 010A through 039A IOMM ACZ1... -
Page 43: Optional Controls
When the bypass valve starts to open, the refrigerant line on the evaporator side of the valve will begin to feel warm to the touch. IOMM ACZ1 ACZ 010A through 039A... - Page 44 External Equalizer Connection to Suction Side of Evaporator To Evaporator Inlet Discharge Hot Gas After Expansion Valve Line Bypass Valve Figure 14, Hot Gas Bypass Adjustment REMOTE BULB ADJUSTMENT RANGE TEMP (°F) AT BULB LOCATION ACZ 010A through 039A IOMM ACZ1...
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Page 45: Troubleshooting Chart
4. See steps for high discharge pressure 5. Unbalanced voltage 5. Check voltage. Contact power company. 1. Operating beyond design conditions 1. Add facilities so conditions are within allowable limits COMPRESSOR THERMAL SWITCH OPEN IOMM ACZ1 ACZ 010A through 039A... - Page 46 ACZ 010A through 039A IOMM ACZ1...
- Page 48 Post Office Box 2510, Staunton, Virginia 24402 USA • (540) 248-0711 • www.mcquay.com...
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