Installation, Operation and Maintenance Manual IOMM ACZ/AGZ Group: Chiller Part Number: 074644101 Effective: July 1998 Supersedes: New AIR-COOLED, SCROLL COMPRESSOR, SPLIT SYSTEMS Chiller w/ Remote Evaporator, AGZ 030AM-050AM Condensing Units, ACZ 030A-055A DX Evaporators, CDE 60 Hertz, English and Metric Global Chiller Line, R-22 © 1997 McQuay International
Table of Contents Introduction ......................................3 Inspection .................................................. 3 Installation ........................................4 Handling.................................................... 4 Location..................................................... 5 Service Access ........................................... 5 Vibration Isolators ..................................... 7 Water Piping.............................................. 8 Flow Switch.
Introduction IMPORTANT INFORMATION This Installation and Operating Manual contains information on three different McQuay product lines • Model AGZ-AM This is a split packaged chiller consisting of an outdoor unit and an evaporator shipped loose for remote mounting. Liquid line specialties are field supplied and mounted. Capacity control is either Johnson UNT or McQuay’s MicroTech Control.
Installation Note: Installation is to be performed by qualified personnel who are familiar with local codes and regulations. WARNING Sharp edges and coil surfaces are a potential hazard. Avoid contact with them. Handling Be careful to avoid rough handling of the unit. Do not push or pull the unit from anything other than the base. Block the pushing vehicle away from the unit to prevent damage to the sheet metal cabinet and end frame (see Figure 1).
Location Unit Placement AGZ-AM and ACZ units are for outdoor applications and can be mounted on a roof or ground level. Set units on a solid and level foundation. For roof mounted applications, install the unit on a steel channel or I-beam frame to support the unit above the roof. For ground level applications, install the unit on a substantial base that will not settle. A one piece concrete slab with footings extended below the frost line is recommended.
Figure 3, Clearance Requirements 6 IOMM ACZ/AGZ
Vibration Isolators Vibration isolators are recommended for all roof mounted installations or wherever vibration transmission is a consideration. Table 1 and Table 2 list isolator point loads for all unit sizes, Figure 4 shows isolator locations. See Dimensional Data for detailed dimensions required to secure each isolator to the mounting surface. The spring flex isolators are white type CP2-32, McQuay part number 047792932. A total of four per unit is required.
Water Piping Local authorities can supply the installer with the proper building and safety codes required for safe and proper installation. Install piping with minimum bends and changes in elevation to minimize pressure drop. Consider the following when installing water piping: 1. 2. 3. Vibration eliminators to reduce vibration and noise transmission to the building. Shutoff valves to isolate the unit from the piping system during unit servicing.
Figure 5, Typical Evaporator Field Water Piping Flow Switch Mount a water flow switch in either the entering or leaving water line to shut down the unit when water flow is interrupted. A flow switch is available from McQuay (part number 0017503300). It is a “paddle” type switch and adaptable to any pipe size from 3” (76mm) to 8” (203mm) nominal. Certain minimum flow rates are required to close the switch and are listed in Table 3. Installation should be as shown in Figure 6.
Glycol Solutions The system glycol capacity, glycol solution flow rate in GPM, and pressure drop through the cooler may be calculated using the following formulas and table. Note: The procedure does not specify the type of glycol. Use the derate factors found in Table 4 for corrections when using ethylene glycol and those in Table 5 for propylene glycol. 1. Capacity -- Find the reduced capacity by multiplying the chiller’s capacity with water by the capacity correction factor C. 2.
Table 6, Capacity and Power Derates Chilled Water Delta-T ALTITUDE SEA LEVEL 2000 ft. 610 m 4000 ft. 1220 m 6000 ft. 1830 m °F 6 8 10 12 14 16 6 8 10 12 14 16 6 8 10 12 14 16 6 8 10 12 14 16 °C 3.3 4.4 5.6 6.7 6.8 8.9 3.3 4.4 5.6 6.7 6.8 8.9 3.3 4.4 5.6 6.7 6.8 8.9 3.3 4.4 5.6 6.7 6.8 8.9 0.00025 (0.044) Cap. kW 0.992 0.995 0.995 0.997 1.000 1.000 1.005 1.002 1.010 1.005 1.014 1.007 0.978 1.005 0.982 1.007 0.986 1.009 0.992 1.011 0.997 1.014 1.000 1.016 0.966 1.016 0.969 1.018 0.973 1.021 0.978 1.
Figure 7, Pressure Drop Curve AGZ 030AM - 040AM CDE 1004-1 AGZ 045AM - 050AM CDE 1204-3 CDE AGZ-AM NOMINAL MAXIMUM MINIMUM Unit Unit Pressure Drop Flow Pressure Drop Flow Pressure Drop Flow Size Size (ft) of Water (gpm) (lps) (ft) of Water (gpm) (lps) (ft) of Water (gpm) (lps) 1004-1 030AM 7.4 73 4.61 18.7 122 7.68 3.2 46 2.88 x 035AM 9.2 82 5.17 23.1 137 8.62 3.9 51 3.23 x 040AM 11.5 93 5.87 28.8 155 9.78 4.9 58 3.67 1204-3 045AM 11.2 106 6.69 28.2 177 11.15 4.8 66 4.18 x 050AM 13.4 117 7.38 33.
Refrigerant Piping Introduction Proper refrigerant piping can represent the difference between a reliable, trouble free system and months or years of inefficient, problematic performance. System concerns related to piping are: 1. Refrigerant pressure drop 2. Solid liquid feed to the expansion valve(s) 3. Continuous oil return Of the three listed, the most important and least understood is number 3. “Continuous oil return”.
d. If a vertical riser exists including the trap at the coil, determine the minimum tons for the circuit. Add b and c above to obtain the total equivalent feet. Use ASHRAE Table 3 (for R22) or Table 4 (for R134a). Suction line selections are based upon the pressure equivalent of a 2ºF loss per 100 equivalent feet. Select a line size that displays an equal or slightly larger tons then that determined in 1a) above. To determine the actual line loss: 1.
With the minimum tons known, a smaller line size should be selected from ASHRAE Chapter 2, Table 13 or 14 capable of entraining oil at the reduced tons. The smaller sized line should be the one installed to be always active. The net internal area of this smaller sized line (see Table 13 or 14) should be deducted from the area of the size selected in paragraph 1) immediately above. The remainder represents the area of the other riser.
Installation, Operation and Maintenance Manual IOMM ACZ/AGZ Group: Chiller Part Number: 074644101 Effective: July 1998 Supersedes: New TO H N I TC R O N P SS O TIO RE C P SU OM EC ON LY TO H N ITC R O N P SO TIO RES C SU O M P EC ON LY A B LIQUID TO COIL LIQUID TO COIL DUAL RISER SUCTION TRAP SHORT AS FITTINGS PERMIT EXPANSION VALVE CONTROL BULB STRAP TO LINE AND INSULATE SUCTION TRAP SHORT AS FITTINGS PERMIT EXPANSION VALVE CONTROL BULBS STRAP TO LINE AND INSULATE Liquid Lines Liquid lines a
side to the condenser side of the circuit. The relief can be sized for a pressure differential from 80 to 180 psi, but not more than 180 psi, and should be auto-resetting as the pressure is relieved. CAUTION: The liquid line should not include a check valve unless the line also includes an automatic resetting pressure relief device.
Table 7, Liquid Line Components System#1 Nom.R-22 Tons (mbh) 15.9 (191) Sporlan Part Number Shown - (Equivalents Are Acceptable) Filter Solenoid Sight Expansion Unit Conn. Drier Valve Glass Valve In/Out C-487 E19S270 SA-17S OVE-20 7/8-1-3/8 ACZ035A System #1 System #2 15.9 (191) 19.1 (229) C-487 C-487 E19S270 E19S270 SA-17S SA-17S OVE-20 OVE-20 7/8-1-3/8 7/8-1-3/8 ACZ040A System#1 19.2 (230) C-487 E19S270 SA-17S OVE-20 7/8-1-3/8 ACZ045A System#1 21.
Physical Data AGZ-AM Table 8, AGZ 030AM - 050AM PHYSICAL DATA STANDARD EFFICIENCY CAPACITY @ ARI Conditions (1), Tons (kW) OUTDOOR UNIT BASIC DATA Number Of Refrigerant Circuits Unit Operating Charge, R-22, Lbs.(2) Unit Operating Charge, R-22, (kg) (2) Cabinet Dimensions, LxWxH, In. Cabinet Dimensions, LxWxH, (mm) 030AM 30.5 (107.2) Ckt.1 Ckt.2 2 34 34 (15.4) (15.4) 94.0 x 88.2 x 86.2 2388 x 2241 x 2190 2870 (1300) 2810 (1275) 445 (200) AGZ-AM MODEL NUMBER 035AM 040AM 045AM 34.3 (120.5) 38.9 (136.7) 44.
ACZ Condensing Units Table 9, ACZ 030A - 040A PHYSICAL DATA ACZ MODEL NUMBER STANDARD EFFICIENCY 030A 035A 040A UNIT CAPACITY @ ARI Conditions (1), Tons (kW) 31.8 (111.7) 35.0 (123.0) 38.4 (134.9) BASIC DATA Ckt.1 Ckt.2 Ckt.1 Ckt.2 Ckt.1 Ckt.2 Number Of Refrigerant Circuits 2 2 2 Unit Operating Charge, R-22, Lbs. (2) 30 30 30 30 30 30 Unit Operating Charge, R-22, (kg) (2) (13.6) (13.6) (13.6) (13.6) (13.6) (13.6) Cabinet Dimensions, LxWxH, In. 94.0 x 88.2 x 86.2 94.0 x 88.2 x 86.2 94.0 x 88.2 x 86.
Table 10, ACZ 045A - 055A PHYSICAL DATA STANDARD EFFICIENCY ACZ MODEL NUMBER 050AS Ckt.1 Ckt.2 48.8 (171.4) 2 35 35 (15.9) (15.9) 94.0 x 88.2 x 86.2 2388 x 2241 x 2190 3095 (1404) 3025 (1372) 445 (200) 055AS BASIC DATA Ckt.1 Ckt.2 Ckt.1 Ckt.2 Unit Capacity @ ARI Conditions (1), Tons (kW) 43.6 (153.2) 53.5 (188.0) Number Of Refrigerant Circuits 2 2 Unit Operating Charge, R-22, Lbs. (2) 30 30 35 35 Unit Operating Charge, R-22, (kg) (2) (13.6) (13.6) (15.9) (15.9) Cabinet Dimensions, LxWxH, In. 94.0 x 88.
Electrical Data Field Wiring Power Wiring CAUTION Internal power wiring to the compressors for single and multiple point option are different. Field wiring must be installed according to unit wiring diagram. 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. Aluminum or copper can be used for all other wiring.
Electrical Data AGZ-AM Electrical Data ACZ Table 11, AGZ-030AM - 050AM, ACZ 030A - 055A, 60 Hz, Single Point Power Electrical Data Minimum Circuit Volts Ampacity (MCA) 208 117 230 117 030A 380 77 460 61 575 48 208 131 230 131 035A 030AM 380 86 460 68 575 53 208 143 230 143 040A 035AM 380 93 460 73 575 58 208 159 230 159 045A 040AM 380 111 460 78 575 67 208 183 230 183 050A 045AM 380 116 460 94 575 76 208 198 230 198 055A 050AM 380 120 460 104 575 83 All Electrical Data notes are on page 25 ACZ AGZ-AM Unit
Table 12, AGZ-AM, ACZ A, 60 Hz, Compressor & Condenser Fan Motor Amp Draw Rated Load Amps Compressors Volts No. No. Fan 1&3 2&4 Motors (Each) (Each) (Each) 208 23.7 23.7 4.0 230 23.7 23.7 4.0 030A 380 14.9 14.9 3.4 460 12.5 12.5 2.0 575 9.1 9.1 2.3 208 23.7 29.9 4.0 230 23.7 29.9 4.0 035A 030AM 380 14.9 18.6 3.4 460 12.5 15.3 2.0 575 9.1 11.6 2.2 208 29.9 29.9 4.0 230 29.9 29.9 4.0 040A 035AM 380 18.6 18.6 3.4 460 15.3 15.3 2.0 575 11.6 11.6 2.2 208 33.6 33.6 4.0 230 33.6 33.6 4.0 045A 040AM 380 22.8 22.
Electrical Notes Notes for “Electrical Data Single Point” Power: 1. 2. 3. 4. 5. 6. 7. 8. 9. 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 including the control transformer. If the control transformer option is furnished, no separate 115V power is required. If a separate 115V power supply is used for the control circuit, then the wire sizing amps is 10 amps for all unit sizes.
Electrical Legend Figure 9, Electrical Legend 26 IOMM ACZ/AGZ
Wiring Diagrams Figure 10, AGZ-AM, Typical Field Wiring with Global UNT Controller UNIT MAIN TERMINAL BLOCK DISCONNECT (BY OTHERS) GND LUG 3 PHASE TO COMPRESSOR(S) AND FAN MOTORS POWER SUPPLY FUSED CONTROL CIRCUIT TRANSFORMER OPTION 120 VAC DISCONNECT (BY OTHERS) NB N 120VAC CONTROL POWER 10A FUSE (BY OTHERS) SEPARATE EVAPORATOR DISCONNECT 10A HEATER POWER (BY OTHERS) FUSE OPTION 120VAC (BY OTHERS) (BY OTHERS) N FACTORY SUPPLIED ALARM TIME DELAY FIELD WIRED ALARM BELL OPTION ALARM BELL TB2 1 2
Figure 11, AGZ-AM, Typical Field Wiring Diagram with MicroTech Controller UNIT MAIN TERMINAL BLOCK DISCONNECT (BY OTHERS) GND LUG 3 PHASE POWER TO COMPRESSOR(S) AND FAN MOTORS SUPPLY FUSED CONTROL CIRCUIT TRANSFORMER OPTION 120 VAC DISCONNECT (BY OTHERS) NB N 10A FUSE 120VAC CONTROL POWER (BY OTHERS) SEPARATE EVAPORATOR DISCONNECT 10A HEATER POWER (BY OTHERS) FUSE OPTION 120VAC (BY OTHERS) (BY OTHERS) N 24V OR 120VAC (BY OTHERS) N CHW PUMP RELAY (BY OTHERS) FACTORY SUPPLIED ALARM FIELD WIRED ALAR
Figure 12, AGZ-AM, Single-point Connection with FanTrol IOMM ACZ/AGZ 29
Figure 13, AGZ-AM, Single-point Connection with SpeedTrol 30 IOMM ACZ/AGZ
Figure 14, AGZ-AM, Unit Control Schematic (UNT) IOMM ACZ/AGZ 31
Figure 15, AGZ-AM, Staging Schematic (UNT) 32 IOMM ACZ/AGZ
Figure 16, AGZ-AM, MicroTech Controller Schematic IOMM ACZ/AGZ 33
Figure 17, AGZ-AM, Unit Control Schematic (MicroTech) 34 IOMM ACZ/AGZ
Figure 18, AGZ-AM, Staging Schematic (MicroTech) IOMM ACZ/AGZ 35
Figure 19, ACZ Field Connection Diagram (No Capacity Control) 36 IOMM ACZ/AGZ
Figure 20, ACZ Field Wiring Diagram (Capacity Control Staging) IOMM ACZ/AGZ 37
Dimensional Data AGZ-AM ACZ Figure 21, Dimensions AGZ 030AM - 050AM and ACZ 030A - 055A ACZ MODEL NUMBER 030A 035A 040A 045A 050A 055A 38 AGZ MODEL NUMBER 030AM 035AM 040AM 045AM 050AM DIMENSIONS inches (mm) A B 86.2 (2190) 81.7 (2075) 86.2 (2190) 81.7 (2075) 86.2 (2190) 81.7 (2075) 86.2 (2190) 81.7 (2075) 86.2 (2190) 81.7 (2075) 86.2 (2190) 81.7 (2075) CENTER OF GRAVITY inches (mm) X Y Z 42.8 (1087) 35.8 (909) 39.7 (1008) 42.8 (1087) 35.8 (909) 39.7 (1008) 42.8 (1087) 35.9 (911) 40.0 (1016) 42.
CDE Figure 22, CDE 1004-1 - 1204-3 CDE MODEL NUMBER CDE-1004-1 CDE-1204-3 CDE-1204-2 CDE MODEL NUMBER CDE-1004-1 CDE-1204-3 CDE-1204-2 CDE MODEL NUMBER CDE-1004-1 CDE-1204-3 CDE-1204-2 CDE MODEL NUMBER CDE-1004-1 CDE-1204-3 CDE-1204-2 IOMM ACZ/AGZ WATER CONNECTION INCHES (mm) L P 8.5 (216) 4.0 (102) 9.5 (241) 4.0 (102) 9.5 (241) 4.0 (102) C 39.3 (998) 39.3 (998) 39.3 (998) A 52.5 (1334) 53.5 (1359) 53.5 (1359) K 3.0 (76) 3.0 (76) 3.0 (76) B 15.5 (394) 17.5 (445) 17.5 (445) R 50.0 (1270) 50.
Startup Pre Start-up The system components must be inspected to ensure that nothing has became loose or damaged during shipping or installation. Start-Up For AGZ-AM units refer to the Global UNT Controller or MicroTech Controller sections to become familiar with the operation before starting chiller. For ACZ units, the field furnished and installed capacity control system should be thoroughly understood prior to starting the unit.
Extended 1. 2. 3. 4. 5. Front seat both condenser liquid line service valves. Put both circuit switches in Pumpdown and Stop position. After the compressors have stopped, put System Switch (S1) in Emergency Stop position. Front seat both refrigerant circuit discharge valves. If chilled water system is not drained, maintain power to the evaporator heater to prevent freezing. Maintain heat tracing on the chilled water lines. 6. Drain evaporator and water piping to prevent freezing. 7.
Refrigerant Charging Liquid line subcooling at the liquid shut-off valve should be between 15 and 20 degrees F at full load. If the unit is at steady full load operation and bubbles are visible in the sightglass, then check liquid subcooling. The charge for lines, outdoor units, and CDE evaporators are shown below. The charge for DX evaporators is usually small but should be added in.
Electrical Check Out CAUTION Electrical power must be applied to the compressor crankcase heaters 24 hours before starting unit. 1. Open all electrical disconnects and check all power wiring connections. Start at the power block and check all connections through all components to and including the compressor terminals. These should be checked again after 3 months of operations and at least yearly thereafter. 2.
Operation Sequence of Operation Starting With control power on, 115Vac power is applied through F1 to the compressor crankcase heaters and control transformer T2. T2 supplies 24Vac to the Global UNT controller. The green light on the Global UNT controller will begin to flash. The panel Alarm Light will illuminate. Put the System Switch S1 into the AUTO position. This applies power to the control circuit and a digital input to the Global UNT controller.
Software Description (Global UNT Interface Kit required to read or change variables) Variable Name LPSS SLPT MLPS LPSD LPFS LPHL LPLL FSTP PDTD Description Default Value Range Low Pressure Starting Setpoint Starting Low Pressure Time Minimum Low Pressure Setpoint Low Pressure Starting Differential Low Pressure Freezestat setpoint Low Pressure High Limit Low Pressure Low Limit Freezestat Time Period Pumpdown Delay Time Period 10 psi 260 sec 5 psi 5 psi 54 psi 57 psi 55 psi 60 sec 60 sec 5 to 15 psi 90
Filter Driers Each refrigerant circuit is furnished with a full flow filter drier or an optional replaceable core type filter-drier. The core assembly of the replaceable core drier consists of a filter core held tightly in the shell in a manner that allows full flow without bypass. Pressure drop across the filter drier at full load conditions must not exceed 10 psig. If pressure drop is more than 10 psig, then replace the filter drier.
The suction superheat for the suction leaving the evaporator is set at the factory for 8° to 12°F at full load. To have full rated unit performance the superheat must be about 8°F at 95°F outdoor ambient. Crankcase Heaters The scroll compressors are equipped with externally mounted band heaters located at the oil sump level. The function of the heater is to keep the temperature in the crankcase high enough to prevent refrigerant from migrating to the crankcase and condensing in the oil during off-cycle.
Global UNT Controller, AGZ-AM This section provides installation, setup and troubleshooting information for the Global UNT controller. All operational descriptions are based on the Global UNT software SUZE4-2A. Operational characteristics may vary with other versions of software. General Description The Global UNT is a microprocessor based leaving water controller designed for multiple stage operation. The Global UNT’s operation is based on an adjustable setpoint and control band.
Unit Set Points and Calibration The control software is installed and tested by the factory before shipping. No periodic calibration of the controller is necessary. All control and safety set points must be checked by the installing contractor and adjusted as necessary before starting the unit. The “setpoint” control knob adjusts the leaving water setpoint. The “Control Band” knob adjusts the controller temperature control band.
Chilled Water Flow Switch The chilled water flow switch is connected to field wiring terminals #142 and #143 on TB-7. When the chilled water pump is enabled, the Global UNT controller checks for proof-of-flow through the flow switch digital input. Digital Outputs The digital outputs are controlled by the Global UNT controller. The outputs are double pole double throw plug-in type relays, with a 24Vac holding coil and 120Vac - 7.0 amp rated contacts. These relays are field replaceable.
Digital Inputs Note: All Digital Inputs are 24Vac supplied by transformer T2 in the control panel. Do not use inputs from another power supply external to the unit. This can cause failure of the Global UNT controller.
As the OAT increases above the Outdoor Air Low Limit (OALL), the Actual Leaving Water Setpoint is decreased from its Leaving High Limit (Leaving Water Setpoint plus Leaving Reset Band) to the Leaving Water Setpoint. When OAT reaches the OAHL, the Actual Leaving Water Setpoint equals the Leaving Water Setpoint (AI4). If the OAT sensor is missing or unreliable, no reset occurs and the Actual Leaving Water Setpoint equals the Leaving Water Setpoint.
Zone Temperature (optional Zone Temperature Sensor ) When selected, a Zone Temperature Sensor is connected to TB-7 terminals #134 and #135. Four variables are used to setup the reset ramp that calculates the Actual Leaving Water Setpoint. These are: Leaving Water Dial Setpoint (AI-4), Reset Band SP selected with the Zone Terminal, Zone Temperature High Limit (ZTHL), and Zone Temperature Reset Band (ZTRB).
Unoccupied Mode When the remote start / stop input is opened, the unoccupied mode is initiated. The chiller will maintain a higher leaving water temperature setpoint (default 70°F) if the chilled water circulation is maintained. The unoccupied leaving water setpoint can be changed from the Zone Terminal. Soft Start Soft loading limits the number of available stages when the unit is started to prevent excessive power consumption and possible overshoot of the leaving water temperature set point.
Freezestat Control On startup the Global UNT controller will check the evaporator pressure after the SLPT(starting low pressure time) timer times out. If the evaporator pressure is greater than the LPHL (low pressure high limit) value, the Global UNT controller will continue to stage up as additional cooling is required. If the evaporator pressure is less than the LPHL, the Global UNT controller will deenergize BO7 or BO8 (depends on circuit starting) which will stop the compressor.
Freezestat reset on the control panel. There is a five minute time delay after depressing the reset button. The chiller must have the manual reset system alarm conditions cleared before normal operation can resume. If the alarm which occurred is an auto-clearing alarm, once the condition has corrected, the chiller will resume normal operation provided the anti-cycle timers have cleared and sufficient load exists.
Figure 26, Zone Terminal Display Item List Display Indicator Dot Warning Signal On/Off Status McQuay AGZ/AGR Global Chiller INSERT 10 Display Button 1 2 3 Mode Selector Button Mode Selector Panel ON Lvg Water Temp Evap Pres #1 Evap Pres #2 OA/AI3 Input OA/AI3 HiLimSP OA/AI3 ResetSP Lvg Water SP LvgWtr RBnd SP Contrl Band SP Actual Lvg SP Unoccpd Lvg SP OA Lockout SP Display Area 11 % Unit Load Lvg Low Lim SP SoftSta Capcty SoftStart Time Cir #1 Starts Cir #2 Starts Display Area 31 Display Area 21
DISPLAYS, SYMBOLS, KEYS, AND BUTTONS The Zone Terminal simultaneously displays three set points or sensed values. In addition, flashing symbols indicate when items are in a state of alarm. The keys, buttons, displays, and symbols are explained below.
CONNECTING THE ZONE TERMINAL You can unit mount the ZT, or use it as a portable tool for convenient access to any chiller information. McQuay Global Scroll Controller Connection A standard telephone-style jack connects the ZT to a McQuay Chiller Controller directly.
Adjustable Points The following McQuay Global Scroll Chiller points are adjustable by the Zone Terminal.
Cir #2 Starts - Counts the number of starts for circuit #2. Note: If power is lost to the controller, this data is lost and will start counting over. When power is applied and kept on, the controller will allow 10 starts for circuit #1 as the lead circuit, then will switch to circuit #2 for the next 10 starts, etc (Automatic Lead/Lag). Occupied - |= On, 0 = Off Flow Failure - |= Alarm, 0 = Normal OA Lockout - Indicates whether your in OA lockout (see OA Lockout SP). No alarm.
Global UNT Controller Troubleshooting Chart PROBLEM Compressor will not run POSSIBLE CAUSES 1. Main switch, circuit breakers open. 2. Fuse blown. 3. Thermal overloads tripped or fuses blown. 4. Defective contactor or coil. 5. System shut down by safety devices. 6. No cooling required. 7. Liquid line solenoid will not open. 8. Motor electrical trouble. 9. Loose wiring. High Discharge Pressure Low Discharge Pressure High Suction Pressure 3. 4. 5. 6. 7. High Ambient conditions.
MicroTech Controller, AGZ-AM All operational descriptions are based on the MicroTech controller software versions AGZ2E01A. Operating characteristics and menu selections may vary with other versions of software. Contact McQuay Technical Support for software update information. General Description The MicroTech control panel contains a model 250-06 microprocessor based controller which provides all control functions.
Remote 4-20 milliamp signals Signals for leaving water reset or demand limit are provided by the installing contractor and connected to the terminal block as indicated by the unit wiring diagram. See Field Wiring diagram for details. Interlock wiring All interlock wiring to field devices (such as flow switches and pump starters) is provided by the installing contractor. See unit wiring diagrams and field wiring diagram.
Field Wiring Interconnecting wiring for the control panel may consist of the following: • 115Vac power wiring • Chilled water pump relay • Analog input signals • Digital input signals • Digital output signals • Network communications • Communications to a personal computer • Telephone line for remote modem access Power Wiring The installing contractor provides the unit voltage power source, disconnect, fuses and necessary wiring for these circuits.
Digital Outputs The digital output board has normally open solid-state relays with an on-board replaceable 5 amp fuse. The status of all outputs are shown by the individual output red LEDs. Chilled Water Pump Relay The optional chilled water pump relay is connected to terminal #10 and #9 on TB-2. When the unit is enabled, the chilled water pump relay is energized. Be sure the relay coil is rated for a maximum load of 1.8 amps at 120Vac.
Controller Inputs /Outputs Analog Inputs Analog inputs are used to read the various temperatures and pressures on the chiller as well as any customer supplied 4-20mA reset signals. The controller’s internal regulated 5Vdc and 12Vdc supplies provide correct operating voltage for the sensors. See Table 22 for details.
Table 24, Relay Board Outputs Digital Output Number 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Output Description Alarm Circuit Chilled Water Pump Relay Liquid Line Solenoid Circuit #1 Liquid Line Solenoid Circuit #2 Compressor #1 Circuit #1 Compressor #2 Circuit #2 Hot Gas Bypass Circuit #1 Hot Gas Bypass Circuit #2 Compressor #3 Circuit #1 Compressor #4 Circuit #2 Condenser Fan (M11) Condenser Fan (M12) Spare Condenser Fan (M21) Condenser Fan (M22) Spare Reset Options User reset options are located in the “L
The remote 4-20mA input must be 4mA or less and the leaving water temperature will be controlled to the calculated setpoint. When the remote reset input is above 4mA, the value “MaxChwRst” is added to the leaving water setpoint. This will be the day operating setpoint. This value cannot be reset when in the day mode by any other reset options. The alarm setpoints must be adjusted to allow operation of the chiller at the lower temperatures.
Manual Operation Manual operating modes are available to simplify setup and troubleshooting of the unit. Any of the following manual modes may be selected from the Control Mode Menu. Note: These manual settings are intended to aid in troubleshooting and should not be considered to be normal operating modes. The equipment should not be left unattended during manual operation as the automatic staging controls are disabled.
Pumpdown Control The AGZ units have a one time pump down. If two compressors are operating on a refrigerant circuit and the chiller is commanded to stop, the lag compressor on that circuit will stop and the lead compressor will pump the circuit down. Pump down pressure depends on the chiller’s refrigerant type. Certain alarm conditions will not permit chiller pumpdown.
Circuit Alarm Conditions The “Circuit Alarm Conditions” are those alarms which only affect one circuit and can stop the compressors of that circuit. These alarms are: • Compressor Motor Protection • High Condenser Pressure • Mechanical High Pressure Switch • Low Evaporator Pressure • Refrigerant Freeze Protection • Bad Pressure Transducer The chiller must have the manual reset system alarm conditions cleared before normal operation can resume.
If an alarm condition exists which prevents normal operation of both refrigerant circuits, the chiller will be disabled and the display will indicate OFF:Alarm. Assuming none of the above “OFF” conditions are true, the controller will examine the internal time clock schedule to determine if the chiller should start. The operating mode will be OFF:TimeClock if the time schedule indicates an “OFF” time period. Start - Up If none of the “OFF” conditions are true, the controller will initiate a start sequence.
Start-Up and Shutdown Pre-Start Checkout Configuration default set points are entered at the factory and all values must be checked and reset for each installation. Make sure the field wiring for all flow switches, interlocks or jumpers matches the connections detailed on the field wiring drawing. Setting of the HEX Address Switches The controller HEX address switches for each unit determine its logical address in a MicroTech network or in an Open Protocol network.
rises above the LPCutIn value, a compressor on the lead circuit will start. Refer to the unit staging schematic to determine which LED is associate to a compressor. The controller will stage up and down to maintain the desired leaving water temperature. Temporary Shutdown Close both pumpdown switches. After pumpdown is completed, turn off the system switch. Open the remote start / stop input and the evaporator pump will stop. Perform the reverse to start up after a temporary shutdown.
Menu Structure (general description) The information stored in the MicroTech controller can be accessed through the keypad using a treelike structure. This tree structure is divided into Categories, Menus and Menu Items. There are three Categories which make up the tree structure: STATUS, CONTROL, and ALARM. Each category is divided into Menus and each Menu into Menu Items.
minutes so the password only needs to be entered once per session. After 5 minutes of inactivity, the password access time will expire providing protection against unauthorized users.
Keypad Key Functions The MicroTech keypad consists of twelve pressure sensitive membrane switches (refer to Figure 29). These keys are used to step through, access, and manipulate the information in the MicroTech controller tree structure. The keypad keys are divided into four groups with two or four keys in each. These groups of keys and their functions are described below. Category Group The keys in this group provide quick access to strategic menus throughout the menu tree-structure.
Decr.When changing the value of a menu item entry, pressing “DECR. -” shifts the menu item display line to the next lower value or previous available selection. EnterOnce a change has been made to a desired value, pressing “ENTER” locks in the new value. ClearPressing “ALARMS” followed by “CLEAR” clears the current alarm. Also, when a change is made to a menu item pressing “CLEAR” returns the display to the original value as long as “ENTER” has not been pressed.
Menu #6: Circuit 62 PressuresThe circuit #2 evaporator and condenser refrigerant pressure readings are displayed under this menu. The calculated minimum and maximum condenser pressure values are also shown. Menu #7: Circuit #l TemperaturesThe circuit #I refrigerant temperatures are calculated from their corresponding pressure sensors and displayed here. If the optional Sensors are not present, the line item will flash “Open”.
("MaxChWRst"). At 4mA or less, no reset will occur. At 20mA, the chilled water set point will be reset to a value equaling the Leaving Evaporator Water Set Point ("Lvg Evap") plus the value stored in the "MaxChWRst". Any milliamp value between 4 and 20mA will cause a proportional value of the Maximum Chilled Water Reset to be added to the Leaving Chilled Water Set Point.
Figure 30, Delta-T Setpoints for Chillers Menu #15: Softload Set Points—The controller can limit the number of available stages when the unit is initially started to prevent excessive power consumption and help control overshoot of the water temperature set point. The maximum number of stages will equal the Soft Load Maximum Stages for the time period defined in the softload timer set point. If the softload timer is set to zero, no soft loading will take place.
will advance to the Year position on the display. Use the Incr, Decr, and Enter keys to set the correct Year. Press the Next Item key. The display will show the current Day, Hour, Minute and Second. If this information needs to be changed, follow the same procedure used to set the Date in the previous section. Menu #20: Daily Schedule—This section will help you to set the Daily Start/Stop time for automatic operation of the chiller.
Menus for the AGZ MicroTech Controller Table 26, MENU 1 Chiller Status Table 29, MENU 4 Water Temp's Screen 1 Screen 1 2 Display OFF: Manual Mode OFF: System Sw OFF: Remote Comm OFF: Remote Sw OFF: Time Clock OFF: Alarm OFF: PumpDnSw's Starting WaitForFlow WaitForLoad StageUp StageDn Stage Manual InterStg=xxx sec 2 3 Display Lvg Evap= xxx.x °F (°C) Short °F (°C) Open °F (°C) Ent Evap= xxx.
Table 32, MENU 7 Circ #1 Temp's Screen 1 2 3 4 5 6 Display Satur Evap=xxx°F (°C) N/A **°F (°C) SuctLine = xxx.x°F (°C) Open °F (°C) Short °F (°C) Super Ht =xxx.x°F (°C) N/A ** °F (°C) Satur Cond = xxx°F (°C) N/A **°F (°C) Liquid Ln = xxx.x°F (°C) N/A ** °F (°C) SubCoolg= xxx.
Table 38, MENU 13 Control Mode Screen 1 Display Manual Unit Off Automatic Manual Staging Factory Setpoint Manual Unit Off Range 2 Manual Stage=xx 0 1-8 Table 39, MENU 14 Lvg Evap Spts Values for R-22 refrigerant, ( ) indicates Centigrade values Screen Display Factory Setpoint 1 Actv Spt=xxx.x °F (°C) 2 Lvg Evap=xxx.x °F (°C) 44 (6.7) 3 CntrlBand x.x °F (°C) 3.0 (1.6) 4 StartUpD-T= x.x °F (°C) 3.0 (1.6) 5 ShutDn D-T= x.x °F (°C) 1.5 (0.8) 6 MaxPullDn= x.x °F (°C) 0.5 (0.
Table 41, MENU 15 SoftLoad Spts Screen 1 2 3 4 Display Time Left= xxmin SoftLoad= xx min SoftLdMaxStg= x LoadDelay= xxsec Factory Setpoint Range 20 4 15 0 - 254 1-4 0 - 254 Factory Setpoint Auto Range 1234 1432 2143 2341 3214 3412 4123 4321 15 5 5 - 40 3 - 30 Disable / Enable Disable / Enable Disable / Enable Disable / Enable Table 42, MENU 16 CompressorSpt Screen 1 Display Sequence=Auto 2 3 4 5 StageUp= xxx sec StageDn= xxx sec MinST-ST=xx min MinSP-ST xx min Comp #1 Comp #2 Comp #3 Comp #4 T
Table 47, MENU 20 Schedule Screen 1 2 3 4 5 6 7 8 9 10 Display Override= xx.xx hr NMPSchedule= N/A Sun 00:00-23:59 Mon 00:00-23:59 Tue 00:00-23:59 Wed 00:00-23:59 Thu 00:00-23:59 Fri 00:00-23:59 Sat 00:00-23:59 Hol 00:00-23:59 Factory Setpoint 0.00 Hr N/A 00:00 - 23:59 00:00 - 23:59 00:00 - 23:59 00:00 - 23:59 00:00 - 23:59 00:00 - 23:59 00:00 - 23:59 00:00 - 23:59 Range 00:00 - 63.
Table 51, MENU 23 Misc Setup Screen 1 Display Unit Type= Air Cooled Factory Setpoint Range 2 Units = English English English - Metric 4 5 6 7 SpeedTrol = No Power = 60 hz Port A Baud=xxxx Pre-Alarm=Blink Open Closed Alarm=Closed Blink(N/O) Blink(N/C) OAT Select=None Lcl Rmt LvgEvpAdj= 0.0 °F(°C) EntEvpAdj= 0.0 °F(°C) #1EvpAdj= 0.0psi (kPa) #2EvpAdj= 0.0psi (kPa) #1CndAdj= 0.0psi (kPa) #2CndAdj= 0.
Trouble Analysis for the AGZ MicroTech Controller Microprocessor Control Board The Microprocessor Control Board (MCB) is shown in Figure 31. It contains a microprocessor that is preprogrammed with the software required to monitor and control the chiller. The various MCB connections and components are described below.
Following is the normal start-up sequence that the three status LED’s should follow when power is applied to the MCB: 1. The red (“Reset”) LED turns on and remains on for approximately 5 seconds. During this period the MCB performs a self-test. 2. The red LED turns off and the green (“Running”) LED turns on. This indicates that the microprocessor has passed the self-test and is functioning properly. 3. The amber (“Active”) LED remains off continually if no alarm conditions exist in the network.
Figure 32, Hex Switches HI (left) hex switch LO (right) hex switch 3 4 5 6 7 8 9 A 2 3 4 5 6 BCDE A F 0 1 2 BCDE F 0 1 7 8 9 * Hex switch setting 01 shown Communication Ports The MCB has two communication ports: port A and port B. Each port has six terminals and is set up for both the RS-232C and RS-485 data transmission interface standards. The male and female connectors for these ports are manufactured by AMP.
Test Procedures Status LED Diagnostics The MCB status LED indications can aid in controller diagnostics. If the status LEDs do not operate normally there is a problem with the MCB. Following are troubleshooting procedures for the various symptoms. Red LED Remains On If the red LED remains on after the 5-second self-test period, it is likely that the MCB is defective. However, this can also occur in some instances if there is a power supply problem. Refer to “Troubleshooting Power Problems” below.
6. 7. 8. 9. 10. 11. 12. 13. 94 Reconnect the analog input ribbon cable. Cycle power to the controller and check the power fuses. If both fuses are intact, go to step 7. If either fuse blows, check the ADI board, the connecting ribbon cable, and the field wiring for shorts. Any of these may be defective. Try repeating this step after removing or swapping the ADI board. Reconnect the digital input ribbon cable. Cycle power to the controller and check the power fuses.
Figure 33, MCB Power Supply Terminals POWER IN [18-24 VCT] AC AC GND GND POWER FUSES [BUSSMAN GDC-T2A] 4 3 2 Fuse F1 Fuse F2 1 9 8 7 6 5 4 3 2 1 AUX/OUT Troubleshooting the Keypad/Display Interface The Keypad/Display Interface is connected to the MCB via a ribbon cable and discrete wiring for the back light. The MCB provides operating voltages, control signal outputs for the display, and input conditioning for the keypad inputs.
Troubleshooting Analog Inputs An analog input, such as a temperature sensor, is connected to the ADI board. The analog input is then conditioned by the ADI board. The conditioned input is transferred to the MCB via a ribbon cable. Analog Input not Read by the MCB If the MCB appears to be functioning properly and the analog input is not being read by the MCB, perform the following procedure: 1. 2. 3. Try cycling power to the controller by opening and then closing circuit breaker CB1.
Figure 34, Output Board Relay Socket 1 Fuse 2 *250V ~ 50/60 Hz *120V ~ 50/60 Hz 3 Test Resistor 330-680 Ohm 4 5 LED WARNING Electric shock hazard. Can cause severe injury or death. Even when power to the panel is off, solid-state relay socket terminals 1 and 2 on the output board could be connected to high voltage. Avoid them. One LED Out If one of the Output Board LEDs fails to illuminate when the MCB is commanding the associated output to energize, perform the following procedure: 1. 2. 3.
2. 3. Remove power from the controller by placing CB1 to the OFF position. Disconnect at least one wire from the power input terminals of the Output Board. The resistance should not be less than 3000 ohms. If the resistance is greater than the acceptable value, go to step 3. If the resistance is less than the acceptable value, the Output Board is defective. Check the discrete wiring and connections between the Output board and the Controller. Aux/Out terminal strip and the field wiring terminal strip.
3. 4. Remove power from the controller by opening CB1. Try to improve the connections in the Aux/Out plug insulation displacement terminals by pressing down on the wires with a small screwdriver. Check all other wiring and connectors for bent pins or mis-wires. If the chatter does not stop, the electromechanical relay or contactor is probably defective. Troubleshooting Solid-State Relays As shown on the unit wiring diagrams, the Solid-State relays on the Output Boards all have normally open “contacts.
Unit Maintenance General On initial start-up and periodically during operation, it will be necessary to perform certain routine service checks. Among these are checking the liquid line sightglasses, taking condensing and suction pressure readings, and checking to see that the unit has normal superheat and subcooling readings. A recommended maintenance schedule is located at the end of this section. Compressor Maintenance The scroll compressors are fully hermetic and require no maintenance.
drier. Subcooling should be checked at full load with 70°F (21.1°C) outdoor air temperature and all fans running. An element inside the sightglass indicates the moisture condition corresponding to a given element color. If the sightglass does not indicate a dry condition after about 12 hours of operation, the circuit should be pumped down and the filter-drier changed.
Service CAUTION 1. Service on this equipment is to be performed by qualified refrigeration personnel familiar with equipment operation, maintenance, correct servicing procedures, and the safety hazards inherent in this work. Causes for repeated tripping of safety controls must be investigated and corrected. 2. Disconnect all power before doing any service inside the unit. 3.
Evaporator The remote evaporator on AGZ-AM units and CDE evaporators are the direct expansion, shell-andtube type with refrigerant flowing through the tubes and water flowing through the shell over the tubes. The tubes are internally finned to provide extended surface as well as turbulent flow of refrigeration through the tubes. Normally no service work is required on the evaporator.
2. Add the charge to the system through the suction shutoff valve or through the Schrader fitting on the tube entering the evaporator between the compressor and the evaporator head. 3. The charge can be added at any load condition between 25-100% load per circuit but at least twoF fans should be operating per refrigerant circuit if possible. The suction superheat should be in the 6°F-12°F (3.3°C-6.6°C) range. 4.
Troubleshooting Chart PROBLEM Compressor will not Run 1. 2. POSSIBLE CAUSES Main Switch. Fuse Blown. Circuit breakers open 1. 2. 3. Thermal overloads tripped 3. 4. 5. Defective contactor or coil. System Shutdown by safety devices 4. 5. 6. 7. 8. 9. No cooling required Liquid line solenoid will not open Motor electrical trouble Loose wiring 6. 7. 8. 9. POSSIBLE CORRECTIVE STEPS Close Switch. Check electrical circuits and motor windings for shorts or grounds. Investigate for possible overloading.
13600 Industrial Park Boulevard, P.O.
