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IOM 686

AGZ 030A through 065A

85

2. 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.

3. Check the discrete wiring and connections between the Output board and the Controller.  Aux/Out

terminal strip and the field wiring terminal strip.

Note: The MCB Aux/Out connector plug terminals displace wire insulation to make contact
with the conductor. If a faulty Aux/Out connections is suspected, try pressing down on the
wire in the terminals with a small screwdriver.

LED Lit, Output not Energized

If the LED of a suspect output is lit but the load connected to it is not energized, and everything is
intact between the MCB and the coil side of the relay, perform the following procedure to isolate the
problem:

1. Verify that 24 or 120 Vac power is present at the suspect output’s screw terminal on the Output

Board.

2. Remove power from the controller by opening CB1. Pull the 5-amp fuse on the contact side of

the relay and check it for continuity with an ohmmeter.
If the fuse is not bad, reinstall it and go to step 3.
If the fuse is bad, replace it and inspect the load and associated wiring before restoring power.
Note that a fuse from an unused output can be substituted for the bad fuse.

3. Remove power from the controller by opening CB1. Swap the suspect relay with a known good

relay. Try to choose a relay that will not affect unit operation. Restore power by closing CB1.
If the output load energizes, the suspect relay is bad. Replace the relay.
If the output load does not energize (when LED is lit again), check the load circuit wiring and
components.

Output Energized, LED not Lit

If the LED of a suspect output is not lit, but the load connected to it is energized, either the Solid-State
relay or the MOV is bad. The Solid-State relay contacts and the MOV, which are in parallel, can both
fail closed. Perform the following procedure to isolate the problem:

1. Remove power from the controller by opening CB1. Pull the Solid-State relay from the suspect

output’s socket.

2. Restore power by closing CB1.

If the output load remains energized when there is no relay in the socket, the output’s MOV has
failed and the Output Board must be replaced.
If the output load de-energizes, the relay that was pulled is defective.

Contact Chatter

Contact chatter is very rapid opening and closing of contacts. It is usually caused by low voltage at the
electromechanical relay or contactor coil. If contact chatter is occurring on a relay or contactor
connected to one of the Output Board Solid-State relays, it is also possible that a faulty connection
exists on the power supply terminals of the Aux/Out plug connector on the MCB.  In very rare
instances, contact chatter can be caused by a faulty Solid-State relay. Perform the following procedure
to isolate the problem.

1. Verify that the voltage at the load’s power supply and at the Solid-State relay contacts is adequate.

2. Remove power from the controller by opening CB1. Swap the suspect relay with a known good

relay. Try to choose a relay that will not affect unit operation. Restore power by closing CB1.
If the chatter does not stop, go to step 3.
If the chatter stops, the suspect relay is defective. Replace the relay.

Summary of Contents for AGZ 030A

Page 1: ...l IOM 686 Group Chiller Part Number 062994901 Effective March 1997 Supersedes None 1997 McQuay International Air Cooled Global Chiller Type AGZ 030A through 065A 60 Hertz English and Metric Scroll Com...

Page 2: ...NT Interface Kit required to read or change variables 34 Hot Gas Bypass Optional 34 Combination Filter Drier 35 System Adjustment 35 Liquid Sightglass and Moisture Indicator 35 Refrigerant Charging 35...

Page 3: ...reeze protection limited pumpdown during on or off periods compressor lead lag switch to alternate the compressor starting sequence and sequenced starting of compressors The electrical control center...

Page 4: ...he pushing vehicle away from the unit to prevent damage to the sheet metal cabinet and end frame see Figure 1 To lift the unit 2 1 2 64mm diameter lifting holes are provided in the base of the unit Ar...

Page 5: ...al control panel and piping components as shown in Figure 3 Do not allow debris to accumulate near the unit Air movement may draw debris into the condenser coil causing air starvation Give special con...

Page 6: ...oof mounted installations or wherever vibration transmission is a consideration lists isolator loads and type Table 2 lists spring isolator part numbers for all unit sizes See Dimensional Data for dim...

Page 7: ...cation with Copper Fins Unit 1 2 3 4 Total Unit Size Lb Kg Lb Kg Lb Kg Lb Kg Lb Kg 030AS 946 429 1066 484 873 396 985 447 3870 1755 035AS 960 435 1082 491 886 402 997 452 3925 1780 040AS 973 441 1096...

Page 8: ...lso be protected to prevent freezing 9 If the unit is used as a replacement chiller on a previously existing piping system flush the system thoroughly before unit installation Regular water analysis a...

Page 9: ...re switches are not recommended for outdoor installation Table 3 Flow switch minimum flow rates NOMINAL PIPE SIZE MINIMUM REQUIRED FLOW TO INCHES MM ACTIVATE SWITCH GPM L S 1 25 4 6 00 0 38 11 4 31 8...

Page 10: ...ate glycol solution hydrometer similar to that found in service stations to determine the freezing point Obtain percent glycol from the freezing point table below On glycol applications it is normally...

Page 11: ...0 951 8 4 4 0 969 1 018 0 947 1 001 0 896 0 953 10 5 6 0 973 1 021 0 952 1 005 0 900 0 956 4000 feet 12 6 7 0 978 1 025 0 956 1 008 0 904 0 958 14 6 8 0 982 1 027 0 959 1 011 0 909 0 960 16 8 9 0 986...

Page 12: ...1 00 3 22 040A 10 4 31 1 93 00 5 87 26 1 78 0 155 00 9 78 4 4 13 3 58 00 3 66 045A 6 8 20 3 106 00 6 69 16 9 50 6 176 00 11 10 2 9 8 7 66 00 4 16 050A 8 0 23 9 117 00 7 38 20 1 60 0 195 00 12 30 3 4 1...

Page 13: ...EFFICIENCY FIN AND TUBE TYPE WITH INTEGRAL SUBCOOLING Coil Face Area Sq Ft 46 4 46 4 46 4 46 4 46 4 46 4 46 4 46 4 Coil Face Area M2 4 3 4 3 4 3 4 3 4 3 4 3 4 3 4 3 Finned Height x Finned Length In 80...

Page 14: ...5 50 75 100 0 25 50 75 100 CONDENSERS HIGH EFFICIENCY FIN AND TUBE TYPE WITH INTEGRAL SUBCOOLING Coil Face Area Sq Ft 46 4 46 4 46 4 46 4 46 4 46 4 58 0 58 0 Coil Face Area M2 4 3 4 3 4 3 4 3 4 3 4 3...

Page 15: ...25 50 75 100 0 25 50 75 100 CONDENSERS HIGH EFFICIENCY FIN AND TUBE TYPE WITH INTEGRAL SUBCOOLING Coil Face Area Sq Ft 46 4 46 4 46 4 46 4 46 4 46 4 Coil Face Area M2 4 3 4 3 4 3 4 3 4 3 4 3 Finned H...

Page 16: ...UPPLY Max Fuse AGZ Circuit Field Wire Hub or Unit Volts Ampacity Wire Nominal HACR Breaker Size MCA Quantity Gauge Quantity Size Size 208 129 3 1 1 1 25 32 150 230 129 3 1 1 1 25 32 150 030AS 380 86 3...

Page 17: ...8 4 23 7 318 411 230 39 5 52 6 5 8 4 23 7 318 411 055AS 380 28 2 34 6 3 4 4 14 4 188 249 460 19 3 23 7 2 8 4 10 7 158 187 575 17 3 19 0 2 3 4 11 5 125 150 208 52 6 52 6 5 8 4 23 7 411 411 230 52 6 52...

Page 18: ...r ampacity in accordance with NEC Voltage drop has not been included Therefore it is recommended that power leads be kept short All terminal block connections must be made with copper type THW wire 5...

Page 19: ...E EVAPORATOR HEATER POWER OPTION IS USED REMOVE WIRES 540 AND 545 120VAC CONTROL POWER 120VAC TB3 19 28 FACTORY SUPPLIED ALARM FIELD WIRED ALARM BELL ALARM BELL OPTION 24VAC GND TB7 140 141 AUTO OFF M...

Page 20: ...0 AND 545 9 10 5A 24V OR 120VAC 120VAC CONTROL POWER 120VAC BY OTHERS N CHW PUMP RELAY BY OTHERS SOLID STATE RELAY 24V OR 120VAC 1 5 AMPS MAX TB3 19 28 FACTORY SUPPLIED ALARM FIELD WIRED ALARM BELL AL...

Page 21: ...IOM 686 AGZ 030A through 065A 21 Figure 10 Single point Connection with FanTrol...

Page 22: ...22 AGZ 030A through 065A IOM 686 Figure 11 Single point Connection with SpeedTrol...

Page 23: ...20 WKURXJK LJXUH 8QLW RQWURO 6FKHPDWLF 817...

Page 24: ...24 AGZ 030A through 065A IOM 686 Figure 13 Staging Schematic UNT...

Page 25: ...IOM 686 AGZ 030A through 065A 25 Figure 14 MicroTech Controller Schematic...

Page 26: ...26 AGZ 030A through 065A IOM 686 Figure 15 Unit Control Schematic MicroTech...

Page 27: ...IOM 686 AGZ 030A through 065A 27 Figure 16 Staging Schematic MicroTech...

Page 28: ...566 4 5 3 133 8 15 0 381 0 43 9 1115 44 6 1133 36 2 920 3535 1605 3460 1570 445 200 045AS 86 2 2189 5 81 7 2075 2 61 6 1565 3 22 3 566 4 5 3 133 8 15 0 381 0 43 9 1115 44 6 1133 37 4 950 3695 1675 362...

Page 29: ...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...

Page 30: ...ssors running in reverse 4 Check for proper phasing Low Suction Pressure 1 Lack of refrigerant 1 Check for leaks Repair and add charge Ckeck liquid sightglass 2 Clogged liquid line filter drier 2 Chec...

Page 31: ...urn water temperature sensor Zone temperature sensor Pre Start up The chiller must be inspected to ensure no components became loose or damaged during shipping or installation Start Up Refer to the Gl...

Page 32: ...tructions Extended 1 Front seat both condenser liquid line service valves 2 Put both circuit switches in Pumpdown and Stop position 3 After the compressors have stopped put System Switch S1 in Emergen...

Page 33: ...ed and if the evaporator pressure is above the LPSS low pressure starting setpoint relay BO7 will be energized starting Compressor 1 and energizing the liquid line solenoid valve SV1 through control r...

Page 34: ...is supplied can provide a load of approximately 10 tons The system load added to the ten tons of the hot gas bypass valve has to exceed the compressor capacity for stage 1 compressors for stable syst...

Page 35: ...een opened for service the element may indicate a wet condition It is recommended that the equipment operate for about 12 hours to allow the system to reach equilibrium before deciding if the system r...

Page 36: ...ers are mounted and connected to the Global UNT controller with sensor cable The evaporator pressure transducers depress the schrader fittings and can be replaced without pumping the unit down The pre...

Page 37: ...ower source 120VAC is supplied from a separate external supply remove wires 540 and 545 as indicated on the unit wiring diagram Power Supplies There are several internal power supplies used by the con...

Page 38: ...e alarm signal is not active during a power failure and will not provide a Loss of Power alarm PC Connection The Global UNT controller can be connected to an IBM or IBM compatible computer for setpoin...

Page 39: ...Number Output Description 1 Circuit 1 Liquid Line Solenoid Valve 2 Circuit 2 Liquid Line Solenoid Valve 3 Compressor 3 Contactor M3 4 Compressor 4 Contactor M4 5 Spare 6 Spare 7 Low Pressure Relay Cir...

Page 40: ...eset LW RB LW S P RW LL R W H L R W R B R W LL R W H L R W R B As the RWT increases above the Return Water Low Limit RWLL the controller decreases the Actual Leaving Water Setpoint from its Leaving Hi...

Page 41: ...ues Remote Reset 2 to 10VDC input When selected a 2 to 10VDC signal is connected to TB 7 terminals 134 and 135 This input can be achieved by using a 4 20mA signal and conditioning it with a 500 ohm re...

Page 42: ...erant circuit 1 has compressor 1 and compressor 3 Compressor 1 will always start first on refrigerant circuit 1 Refrigerant circuit 2 has compressor 2 and compressor 4 Compressor 2 will always start f...

Page 43: ...ressure for 260 seconds After the timer times out the evaporator pressure is checked If the pressure is above the LPHL low pressure high limit default 57psi value the controller stages up on leaving w...

Page 44: ...of water flow is indicated on the optional Zone Terminal The chiller must have the manual reset system alarm conditions cleared before normal operation can resume If the alarm which occurred is an aut...

Page 45: ...check and starts up in the Monitor Mode Monitor Mode lets you view up to three of chiller settings sensed values at a time To allow you to monitor your system a clear plastic Insert factory made and i...

Page 46: ...nt in the HVAC controller with these symbols A bar for On a circle for Off These are always monitor only items If the symbol flashes item is in alarm Red Alarm Light Flashes anytime a problem exists r...

Page 47: ...the right of the Mode Selector Panel flashes when any of the above items are in alarm Alarms cannot be cleared with the ZT The problem must be corrected by maintenance or repair of the affected item...

Page 48: ...Air Reset Band OARB default is 40 F therefore outdoor air reset is 40 80 DegF Lvg Water SP Shows the dial adjustment setpoint Non adjustable from ZT LvgWtr Rbnd SP Can be adjusted through the ZT 0 15...

Page 49: ...lenoid 2 On a call for cooling on circuit 2 the solenoid is energized and opened Frzstat 1Alm If circuit 1 fails on freeze the alarm light on the ZT will light To clear the alarm the Freez Stat Reset...

Page 50: ...controller Replace if defective 3 Replace compressor 4 Check reasons for high condenser pressure Low Suction Pressure 1 Low refrigerant charge 2 Defective expansion valve 3 Dirty filter drier 4 Reduc...

Page 51: ...e Suction line temperature circuit 1 Suction line temperature circuit 2 Liquid line temperature circuit 1 Liquid line temperature circuit 2 Unit amp package Unit amperage Percent total unit amperage i...

Page 52: ...The default settings are suitable for most installations The control mode is factory set for Manual Unit Off Check and set the control and safety settings for the application before starting the unit...

Page 53: ...vailable for the alarm bell option Wire according to the field wiring diagram Analog Input Signals All sensors and transducers required for normal chiller operation are installed and wired at the fact...

Page 54: ...ition the alarm circuit will energize and the alarm status light will be on During a pre alarm condition the alarm output and status light will pulse on for one half second and off for four seconds No...

Page 55: ...Circuit 2 Liquid Line 40 to 263o F 0 1o F Digital Inputs All Digital Inputs are 24 VAC At 7 5 VAC to 24 VAC the digital input contacts are considered closed Below 7 5 VAC the contracts are considered...

Page 56: ...A the leaving water temperature is reset to the maximum Between 4 and 20 mA the leaving water temperature is reset proportionally to the reset input signal Outside Air When selecting Outside Air as th...

Page 57: ...in the chiller is selected The network control panel will send a signal that reflects 0 to 100 reset of the leaving water set point according to the value entered into the MaxChwRst of the unit contr...

Page 58: ...o a safety the number of cooling stages will be decreased and always equal to the number of available compressors for operation At all times the second stage of cooling will have a compressor from eac...

Page 59: ...n alarm of pre alarm condition exists the MicroTech display automatically switches to the alarm menu to alert the user of the condition The MicroTech controller alarms can either be of the manual rese...

Page 60: ...dition and the MicroTech display will show the current alarm condition System alarm conditions are Loss of Water Flow Bad Phase Voltage Chilled Water Freeze Protection Volts Ratio Protection Bad Leavi...

Page 61: ...arted Stage 4 cooling will start the last compressor When the evaporator water temperature is satisfied the reverse will occur with the compressor with the most run hours being stopped in each stage d...

Page 62: ...dition When power is first applied to the control panel through the circuit breaker CB the red RESET LED will illuminate for approximately 3 seconds During this time the controller is checking the con...

Page 63: ...connect if freezing ambient conditions are expected 1 Close the manual liquid line shut off valves Move the circuit 1 and 2 switches to the Pumpdown and Stop position Each operating circuit will pumpd...

Page 64: ...item at a time through a two line by sixteen character LCD display The current MENU is shown on the top line and the current MENU item is shown on the bottom line of the display MicroTech Menu Structu...

Page 65: ...ev Pressing PREV shifts the display to the previous menu Note When Menu I is currently in the display the first menu in the menu tree structure pressing PREV causes an end of menus message to appear i...

Page 66: ...key four times This changes the menu item entry to 42 F 6 Press the ACTION group ENTER key one time This stores the new entry into the MicroTech controller memory 7 Pressing the CATEGORY group STATUS...

Page 67: ...ent of these controls may result in damage to the unit or personal injury Menu 13 Control Mode One of several automatic and manual operating modes may be selected from within this menu Typically the s...

Page 68: ...The Network reset option allows a signal to be sent reflecting 0 100 reset of the Lvg Evap set point chillers or Lvg Cond set point THRs based on the Maximum Chilled Water Reset set point This functi...

Page 69: ...hin this menu The Minimum Lift Pressure is the minimum differential pressure to be maintained across the expansion valve The dead band defines the pressure differential range within which no fan stagi...

Page 70: ...l be started The Low Pressure cut out set point determines the point at which the compressors will shut off during a pumpdown sequence The Refrigerant Freeze and Water Freeze alarm set points may be a...

Page 71: ...ngDown OpenSolenoid Capacity Starting LowAmbStart Table 25 MENU 4 Water Temp s Screen Display 1 Lvg Evap xxx x oF oC Short oF oC Open oF oC 2 Ent Evap xxx x oF oC Short oF oC Open oF oC 3 D T Evap Sho...

Page 72: ...xxxoF oC N A oF oC 2 SuctLine xxx xoF oC Open oF oC Short 3 Super Ht xxx xoF oC N A oF oC 4 Satur Cond xxxoF oC N A oF oC 5 Liquid Ln xxx xoF oC N A oF oC 6 SubCoolg xxx xoF oC N A oF oC 7 CondD T F C...

Page 73: ...8 ResetSig xx xma Not Changeable 9 MaxChWRst xx x oF oC 10 0 5 5 0 0 45 0 0 0 25 0 10 ReturnSpt xx x oF oC 54 0 12 3 15 0 80 0 9 4 26 7 the minus sign is not displayed with three digit numbers Table 3...

Page 74: ...Lift 50 xxx 80 552 70 100 483 690 3 MinLift100 xxx 140 966 100 140 690 966 4 DeadBandMult x x 1 0 8 1 3 5 StageUpErr xxx 400 2760 300 990 2070 6830 6 StageDnErr xxx 100 690 50 400 340 2760 Table 40 ME...

Page 75: ...7 Dur 0 Day s 0 0 31 15 8 Date N A 0 N A 0 Jan Dec 1 31 16 8 Dur 0 Day s 0 0 31 17 9 Date N A 0 N A 0 Jan Dec 1 31 18 9 Dur 0 Day s 0 0 31 19 10 Date N A 0 N A 0 Jan Dec 1 31 20 10 Dur 0 Day s 0 0 31...

Page 76: ...rr Alarm Screen Display 1 Current Alarm 2 0 00 0 00 00 3 Evap x x psi kPa 4 Cond x x psi kPa 5 SuctLine xxx x o F o C 6 LiquisLn xxx x o F o C 7 Evap Lvg xxx x o F o C 8 OAT xx xxo F o C 9 Capacity xx...

Page 77: ...able These inputs are conditioned by the ADI board Analog Inputs Connection The MCB receives conditioned analog inputs from the ADI board through the Analog Inputs connector via a plug in ribbon cable...

Page 78: ...o power to MCB Off On Self test failure or power supply problem On Off MCB operating normally For longer than 5 seconds Table 53 Amber Status LED Indication Amber LED State Indication Off Normal opera...

Page 79: ...via phone lines with a modem Port A can also be used to connect a licensed building automation system to the MicroTech network via Open Protocol The default communications rate is 9600 baud Port B Po...

Page 80: ...levels Use the following procedure to isolate the problem Note that this procedure may require two or three spare MCB fuses Refer to the panel wiring diagram 1 Verify that circuit breaker CB1 is close...

Page 81: ...ively loading the MCB s 5 Vdc power supply Isolate the problem by taking resistance measurements on each of these devices with the wiring disconnected The resistance across the power input terminals o...

Page 82: ...connector pull back the plug about one eighth of an inch and place the test leads against the exposed pins If there is no voltage check the wiring and the connections between the controller s 5 Vdc f...

Page 83: ...CB If the MCB appears to be functioning properly and the digital input is not being read by the MCB perform the following procedure 1 Try cycling power to the controller by opening and then closing ci...

Page 84: ...Remove power from the controller Check the ribbon cable and connections between the OB and the MCB Look for bent pins If the cable and connections are intact go to step 3 3 Remove the relay from the...

Page 85: ...unit operation Restore power by closing CB1 If the output load energizes the suspect relay is bad Replace the relay If the output load does not energize when LED is lit again check the load circuit wi...

Page 86: ...n electromechanical relay If the relay is energized the relay output will be hot If the relay is de energized voltage cannot be measured at the relay output The circuit shown in Figure 23 is similar t...

Page 87: ...IOM 686 AGZ 030A through 065A 87 Notes...

Page 88: ...13600 Industrial Park Boulevard P O Box 1551 Minneapolis MN 55440 USA 612 553 5330...

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