McQuay AGZ 010A Installation Manual

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Installation, Operation and Maintenance Manual

IOMM AGZ1

Air-Cooled Scroll Compressor Water Chillers

AGZ 010A – AGZ 034A 10 to 34 Tons, 35 to 120 kW

R-22, 60 Hertz

Group: Part Number Effective: Supersedes:

Chiller

October 2001

: 330262001

New

Table of Contents

Introduction........................................3

General Description......................................... 3

Inspection ........................................................ 3

Installation....................................................... 3

Handling.......................................................... 3

Location........................................................... 4

Service Access................................................. 4

Vibration Isolators........................................... 6

Chilled Water System...................................... 6

Water Connections........................................... 9

Refrigerant Charge........................................... 9

Unit Component Location............................... 9

Glycol Solutions.............................................. 9

Evaporator Water Flow and Pressure Drop..... 9

Control Layout and Operation.......11

Control Center................................................11

Start-up and Shutdown...................11

Pre Start-up.....................................................11

Start-up...........................................................11

Sequence of Operation................................... 12

Physical Data....................................13

Electrical Data................................. 15

Field Wiring................................................... 15

Dimensional Data............................ 20

System Maintenance....................... 21

General...........................................................21

Lubrication.....................................................21

Electrical Terminals.......................................21

Condensers.....................................................21

Refrigerant Sightglass.................................... 21

Standard MicroTech II Controller 22

Table of Contents........................................... 22

Overview........................................................23

General Description....................................... 23

Using the Controller.......................................30

Service.............................................. 42

Thermostatic Expansion Valve.......................42

Filter-Driers...................................................42

Liquid Line Solenoid..................................... 42

Optional Controls...........................................43

Troubleshooting Chart ...................................45

MODEL CODE

A G

Air-Cooled

Global Series

Scroll Compressor

"McQuay" is a registered trademark of 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"

AGZ 010A through 034A IOMM AGZ1

Z XXX A S



2001 McQuay International

S=Packaged Evaporator M=Remote Evaporator

Vintage

ominal To ns

Introduction

General Description

McQuay air-cooled water chillers are complete, self-contained automatic refrigerating units. Every unit is completely assembled, factory wired, charged, and tested. Each unit consists of air-cooled condensers, Copeland Compliant Scroll hermetic compressor, brazed plate-to-plate evaporator, and complete refrigerant piping. Liquid line components include sight-glass/moisture indicator, solenoid valve, and thermal expansion valve. Other features include a compressor heater, and evaporator heater for chilled water freeze protection.

The electrical control center includes all equipment protection and operating controls necessary for automatic operation. Condenser fan motors are three-phase (except single-phase on No. 1 fan with SpeedTrol option) and started by their own contactors and have inherent overload protection. The compressor has solid-state motor protection for inherent thermal overload protection except Model AGZ 010 that has internal line breakage.

Inspection

Check all items carefully against the bill of lading. Inspect all units for damage upon arrival. Report shipping damage and file a claim with the carrier. 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 unit leaves the factory.

Note:

Unit shipping and operating weights are listed on pages 13 and 14.

Installation

Note:

Installation is to be perform ed by qualified personnel who are familiar with local codes

and regulations, especially concerning refrigerant release to the atmosphere.

WARNING

Sharp edges and coil surfaces are a potential hazard. Avoid contact with them.

Handling

Be careful to avo id r ough hand ling o f the unit. Do not push or p ull t he uni t fr om anything othe r t han the base. Block the pushing vehicle away from the unit to prevent damage to the sheet-metal cabinet and end frame (see Figure 1).

To lift the unit, lifting slots are provided in the base of the unit. Arrange spreader bars and cables to prevent damage to the condenser coils or cabinet (see Figure 2).

IOMM AGZ1 AGZ 010A through 034A

Figure 1, Suggested Pushing Arrange ment

Blocking required across full width

Figure 2, Suggested Lifting Arrangement

Location

Unit Placement

AGZ units are for outdoor applications and can be mounted on a roof or at ground level. Set units on a solid and level foundation. For roof-mounted applications, install the unit on a steel channel or Ibeam 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. Be sure the foundation is level (within 1/2” [13 mm] over its length and width). The foundation must support the operating weights listed in the Physical Data Tables on pages 13 and

14. Since its operation is affected by wind, the unit should be located so that its length is parallel with the

prevailing wind. If this is not practical, use field fabricated wind deflectors.

Service Access

Each end of the unit must be accessible after installation for periodic service. Compressors, filterdriers, and liquid line solenoid valve are accessible from the end of the unit. High-pressure, lowpressure, and motor protector controls are on the compressor. Most operational, safety 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.

AGZ 010A through 034A IOMM AGZ1

Clearances

The flow of air to and from the condenser coil must not be limited. Restricting airflow or allowing air recirculation will result in a decrease in unit performance and efficiency. There must be no obstruction above the unit that would deflect discharge air downward where it could be recirculated back to the inlet of the condenser coil. The condenser fans are propeller type and will not operate with ductwork on the fan outlet.

Install the unit with enough si de clearance for air entrance to the coil and for servicing. Provide service access to the evaporator, compressors, electrical control panel and piping components as shown in Figure 3. Do not block access to the unit with piping or conduit.

Do not allow debris to accumulate near the unit. Air movement may draw debris into the condenser coil causing air starvation. Give special consideration to low ambient operation where snow can accumulate. Keep condenser coils and fan discharge free of snow or other obstructions to permit adequate airflow.

Figure 3, Clearance requirements

4 Ft. (1220mm)

Clearance for Air Inlet

4 Ft.

(1220mm)

Clearance for

Service Access

4 Ft. (1220mm)

Clearance for Air Inlet

The recommended minimum side clearance between two units is 8 feet (2440mm).

4 Ft.

(1220mm)

Clearance for

Service Access

Sound Isolation

The low sound levels of the AGZ chiller are suitable for most applications. When additional sound reduction is necessary, locate the unit away from sound sensitive areas. Avoid locations beneath windows or between structures where normal operating sounds may be objectionable. Reduce structurally transmitted sound by isolating water lines, electrical conduit and the unit itself. Use wall sleeves and rubber isolated piping hangers to reduce transmission of water or pump noise into occupied spaces. Use flexible electrical conduit to isolate sound through electrical conduit. Spring isolators are effective in reducing the low amplitude sound generated by the Discus semi-hermetic compressors and for unit isolation in sound-sensitive areas.

The unit must not be installed in a pit or enclosure that is deeper or taller than the height of the unit unless extra space is provided. The minimum clearance on each side of the unit is 6 feet (1828mm) when installed in a pit. The pit cannot be deeper than the unit.

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 AGZ1 AGZ 010A through 034A

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. is completed, the springs are adjusted upward to loosen the blocks or shims that are then removed.

A rubber anti-skid pad is part of the isolator. Installation of spring isolators requires flexible piping connections and at least three feet of flexible conduit to avoid straining the piping and transmitting vibration and noise.

Table 1, Recommended Vibration Isolators

AGZ UNIT

010A – 034A Rubber-in-shear 010A – 017A Spring Isolators 047792726 4 350014835 All CP-1-26 020A – 034A Spring Isolators

Note: See dimension drawing for location of isolators

ISOLATOR

TYPE

ISOLATOR

PART NO. 021639703 2 LF, RF RP-3 Green 021639701 2

047792726 2 LF, RF CP-1-27 047792727 2

NUMBER

REQUIRED

KIT of FOUR

PART NO.

350014857

350014839

LOCATION

LB, RB RP-3 Red

LB, RB CP-1-26

ISOLATOR

DESCRIPTION

RBI

LBI

RFI

Control

Panel

LFI

Corner Weights

AGZ

Unit

Model

010A 261 367 159 223 013A 372 526 184 260 017A 402 568 200 282 020A 484 621 226 291 025A 499 646 232 301 029A 621 647 326 339 034A 678 784 334 386

RF LF RB LB

Chilled Water System

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. Vibration eliminators to reduce vibration and noise transmission to the building.

2. Shutoff valves to isolate the unit from the piping system during unit servicing.

3. Manual or automatic air vent valves at the high points of the system. Install drains at the lowest points in the system.

AGZ 010A through 034A IOMM AGZ1

4. A means of maintaining adequat e system water pressure (expansi on tank or regulating valve).

5. Temperature and pressure indicators located at the unit to aid in unit servicing. Pressure gauge taps must be installed in the chilled water inlet and outlet piping or as shown in Figure 4.

6. A strainer or other means of removing foreign matter from the water before it enters the pump. Place the strainer far enough upstream to prevent cavitation at the p ump inlet (consult p ump manufacturer for recommendations). The use of a strainer will prolong pump life and keep system performance up.

7. A 40-mesh strainer is required in the water line just before the inlet of the evaporator. This will help prevent foreign material from entering and decreasing the performance of the evaporator.

CAUTION

If separate disconnect is us ed for the 110V supply to the evaporator heating cable, mark the disconnect clearly to ensure disconnect is not acc identally shut off during c old seas ons . This could cause a failure of the evaporator.

8. The brazed plate evaporator has a thermostat and heating cable to prevent freeze-up down to

-20°F (-29°C). It is suggested that the heati ng cable be wired to a separate 110V supp ly circuit. As shipped from the factory, the heating cable is wired to the control circuit. Protect all water piping to the unit from 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 and chemical water treatment on the evaporator is recommended immediately at equipment start-up.

10. When glycol is added to the water system for freeze protection, the refrigerant suction pressure will be lower, cooling performance less, and water side pressure drop greater. If the percentage of glycol is high, or if propylene is used instead of ethylene glycol, the added pressure drop and loss of performance could be substantial. Reset the freezestat and low leaving water alarm temperatures. The freezestat is factory set to default at 38°F (3.3°C). Reset the freezestat setting to approximately 4 to 5 degrees F (2.3 to 2.8 degrees C) below the leaving chilled water setpoint temperature. See the section titled “Glycol Solutions” on page 9 for additional information concerning glycol .

11. Perform a preliminary leak check before insulating the piping and filling the system.

12. Piping insulation should include a vapor barrier to prevent condensation and possible damage to the building structure.

Figure 4, Typical Field Evaporator Water Piping

Vent

Inlet

Outlet

Drain

NOTES

1. Chilled water piping within the unit enclosure must be insulated in the field.

2. Piping should be supported independently of the unit and be installed per local codes.

IOMM AGZ1 AGZ 010A through 034A

Vibration

Eliminators

Strainer

Isolation

Valves

Flow

Switch

System Volume

It is important to have adequate water volume in the system to provide an opportunity for the chiller to sense a load change, adjust to the change and stabilize. As the expected load change becomes more rapid, a greater water volume is needed. The system water volume is the total amount of water in the evaporator, air handling products and associated piping. 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.

For normal comfort cooling applications, where the cooling load changes relatively slowly, we recommend a minimum system volume of five minutes times the flow rate (GPM). For example, if the design chiller flow rate is 120 GPM, we recommend a minimum system volume of 600 gallons (120 GPM x 5 minutes).

Since there are many other factors that can influence performance, systems may successfully operate below these suggestions. However, as the water volume decreases below these suggestions, the possibility of problems increases.

Variable Chilled Water flow

Variab le chilled water flow systems are not recommended for this class of equipment due to limited unloading capability.

Flow Switch

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. Install the switch as shown in Figure 5. Connect the normally open contacts of the flow switch in the unit control center at terminals 4 and 5. There is also a set of normally closed contacts on the switch that can be used for an indicator light or an alarm to indicate when a “no-flow” 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.

Table 2, Flow Switch Settings

Pipe Size

Minimum

Adjustment

Maximum

Adjustment

Flow

Flow Flow

Flow

inch 1 1/4 1 1/2 2 2 1/2 3 4 mm 32 38 51 63 76 102

gpm 4.8 6.3 9.9 15.3 24.4 33.3 Lpm 18.2 22.7 37.5 57.9 92.4 126.0 gpm 3.0 3.6 5.9 9.5 15.4 21.1 Lpm 11.3 13.6 22.3 36.0 58.3 79.9

gpm 7.7 10.0 15.8 23.7 35.5 61.4 Lpm 29.1 37.9 59.8 89.7 134.4 232.4 gpm 5.9 7.0 11.0 17.0 29.2 37.7 Lpm 22.3 26.5 41.6 64.3 110.5 142.7

AGZ 010A through 034A IOMM AGZ1

Water Connections

The unit has 3-inch holes for the chilled water piping to enter the unit. The connections are made to the evaporator water connections located within the unit. Water piping within the unit must be field insulated.

Refrigerant Charge

All units are designed with HCFC-22. See the nameplate for specific refrigerant used. Units are shipped with an operating charge. The operating charge (using HCFC-22) for each unit is shown in in the Physical Data Tables on pages 13 and 14.

Unit Component Location

Control Panel

Tandem Scroll Compressors

Charging Valve

Evaporator

Solenoid Valve, Expansion Valve

Optional Hot Gas Bypass ValveFilter Drier

Glycol Solutions

The use of glycol antifreeze solutions will decrease unit capacity and increase the pressure drop through the cooler. See Product Manual PM AGZ1 for specific ratings and correction factors.

CAUTION

Do not use automotive grade antifreeze. Industrial grade glycols must be used. Autom otive antifreeze contains inhibitors that will cause plating on the copper tubes within the chiller evaporator. The type and handling of glycol used must be consistent with local codes.

Evaporator Water Flow and Pressure Drop

Evaporator flow rate must fall between the minimum and maximum values shown in the evaporator pressure drop curve, Figure 6. Flow rates outside of these limits result in a chilled water Delta-T outside the operating range of the controller.

Measure the chilled water pressur e drop through the evaporator a t field-installed p ressure taps. It is important not to include the effect of valves or strainers in these readings.

Varying chilled water flow through the evaporator while the compressors are operating is not recommended.

IOMM AGZ1 AGZ 010A through 034A

Figure 6, Evaporator Water Pressure Drop Curve

AGZ 010

AGZ 020

AGZ 025

AGZ 029

AGZ 034

AGZ 017

AGZ 013

AGZ

Model

010 15.0 0.9 2.4 7.1 24.0 1.5 5.8 17.3 40.0 2.5 15.2 45.5 013 19.5 1.2 1.5 4.5 31.2 2.0 3.7 11.0 52.0 3.3 9.6 28.9 017 24.0 1.5 1.7 5.0 38.4 2.4 4.1 12.2 64.0 4.0 10.7 32.1 020 30.0 1.9 2.3 6.8 48.0 3.0 5.6 16.7 80.0 5.0 14.5 43.4 025 34.5 2.2 1.8 5.3 55.2 3.5 4.3 13.0 92.0 5.8 11.4 34.3 029 40.7 2.6 1.7 5.0 65.0 4.1 4.0 12.1 108.4 6.8 10.9 32.6 034 49.8 3.1 1.6 4.7 79.7 5.0 3.9 11.7 132.8 8.4 10.4 31.2

Minimum Flow Nominal Flow Maximum Flow

Flow Rate

gpm L/s

Pressure Drop

ft. kPa

Flow Rate

gpm L/s

Pressure Drop

ft. kPa

Flow Rate

gpm L/s

Pressure Drop

ft. kPa

AGZ 010A through 034A IOMM AGZ1

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.

ON/OFF Switch

Control Transformer

24-Volt Trans.

MicroTech II

SpeedTrol Location

Field Connection

Terminals

Start-up and Shutdown

Pre Start-up

1. The chilled-water system should be flushed and cleaned. Proper water treatment is required to prevent corrosion and organic growth.

2. Open all electric disconnects and check all electric connections for tightness.

3. Inspect all water piping for flow direction and correct connections at the evaporator.

4. Verify thermostat water temperature sensor is installed in the leaving water line (supply to building). On all AGZ units the sensor well and sensor are factory mounted.

5. Check compressor oil level. The oil level should be visible in the oil sightglass.

6. Check voltage of the unit power supply and make certain voltage is within ±10% of nameplate rating. Check unit power supply wiring for proper ampacity and a minimum insulation temperature of 75°C. Check for proper phasing using a phase sequence meter.

7. Verify all mechanical and electrical inspections have been completed according to local codes.

8. Open control stop switch S1(off). Turn on the main power and control disconnect switches. This will energize crankcase heaters. Wait at least 24 hours before starting up unit.

9. Open all water flow valves and start the chilled water pump. Check all piping for leaks and vent the air from the evaporator as well as from the system piping. Flush the evaporator and system piping to obtain clean, noncorrosive water in the evaporator.

Non-Fused Disc.

Power Block

Fan Contactors

Fan Protection

Compressor Contactors

Start-up

1. Set temperature controller to the desired chilled water temperature. Set the chilled water Delta-T.

2. Start auxiliary equipment by turning on the following: time clock (if present), ambient thermostat and/or remote on/off switch, chilled water pump.

3. If the controller calls for cooling, the unit will begin the start-up sequence.

4. After running the unit for a short time, check t he oil level in the compressor (1/4 to 1/3 of the glass), rotat ion of fans, and flashing in refrigerant sightgl ass.

IOMM AGZ1 AGZ 010A through 034A

5. Verify superheat temperature is at the factory setting of 8 to 12 degrees F (4.4 to 6.7 degrees 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 sale s representative.

Sequence of Operation

The following sequence of operation is typical for Models AGZ 010A through AGZ 034A. It can vary depending upon options.

Start-Up

With the control circuit power on, 115V power is ap plied through the co ntrol circuit fuse F1 to the compressor crankcase heaters, the compressor motor protections and the primary of the 24V control circuit transformer. The 24V transformer provides power to the microprocessor controller.

When a remote time clock, manual switch, or the unit controller turns on the chilled water pump, the flow switch closes and satisfies the flow requirement. If the chilled water temperature is above the stage-on temperature, and all equipment protection devices are closed, the unit will start. The controller will operate the unit in response to the leaving chiller water temperature, reset signals that may be present and any equipment protection signals that may occur.

Equipment Protection Alarms

The following conditions will shut down the unit and activate the alarm circuit:

• No evaporator water flow Low evaporator pressure

• High condenser pressur e Motor protection system

• Phase voltage protection (Optional) Outside ambient temperature

• Evaporator freeze protection Sensor failures

The following alarms will limit unit operation:

• Condenser pressure stage down, unloads unit at high discharge p ressures

• Low ambient lockout, shuts off unit at low ambient temperatures

• Low evaporator pressure hold, holds stage #1 until pressure rises

• Low evaporator pressure unload, shuts off stage #2

Unit Enable Selection

Enables unit operation from local keypad, digital input, or Building Automation System.

Unit Mode Selection

Selects standard cooling, ice, glycol, or test operation mode.

Condenser fan control

Control of condenser fans is provided by the MicroTech II controller. The control steps condenser fans based on discharge pressure.

Shutdown

As the leaving water control is satisfied, it will stage off the lag compressor unloading the unit. The second stage will de-energize the liquid line solenoid valve SV1 and shut off the lead compressor. The compressor crankcase heaters will energize when the compressors shut off, keeping the small amount of refrigerant in the plate heat exchanger from migrating to the compressor. See page 38 for detailed explanation of compressor staging.

AGZ 010A through 034A IOMM AGZ1

Physical Data

Table 3, Physical Data, AGZ 010A through 017A

PHYSICAL DATA

BASIC DATA

Unit Capacity @ ARI Conditions (1), Tons (kW) 9.8 (34.3) 13.3 (46.6) 15.9 (55.7) Number Of Refrigerant Circuits 1 1 1 Unit Operating Charge, R-22, Lb. (kg) 22.0 (10.0) 24.0 (10.9) 31.0 (14.1) Cabinet Dimensions, LxWxH, In. 73.6 x 46.3 x 50.8 73.6 x 46.3 x 50.8 73.6 x 46.3 x 50.8 Cabinet Dimensions, LxWxH, (mm) (1869) x (1176) x (1289) (1869) x (1176) x (1289) (1869) x (1176) x (1289) Unit Operating Weight, Lb. (kg) 1090 (495) 1340 (608) 1450 (658) Unit Shipping Wei ght, Lb. (kg) 1160 (527) 1400 (636) 1515 (688) Add'l Weight If Copper Finned Coils, Lb. (kg) 220 (99.7) 220 (99.7) 220 (99.7)

COMPRESSORS

Type Scroll Scroll Scroll Nominal Tons Per Compressor 6.0 / 6.0 7.5 / 7.5 9.0 / 9.0 Oil Charge Per Compressor, Oz. (g) 60 (1701) 140 (3969) 140 (3969)

CAPACITY REDUCTION STEPS - PERCENT OF COMPRESSOR DSPLACEMENT

Standard Staging 0 – 50 – 100 0 – 50 – 100 0 – 50 – 100

CONDENSERS - HIGH EFFICIENCY FIN AND TUBE TYPE WITH INTEGRAL SUBCOOLING

Coil Face Area, One of Two Sides, Sq. Ft. (M2) 30.3 (2.8) 30.3 (2.8) 30.3 (2.8) Finned Height x Finned Length, In. 84 x 52 84 x 52 84 x 52 Finned Height x Finned Length, (mm) (2134) x (1321) (2134) x (1321) (2134) x (1321) Fins Per Inch x Rows Deep 16 x 2 16 x 2 16 x 3 Pumpdown Capacity Lb. (kg) 35.3 (16.0) 35.3 (16.0) 50.3 (22.8)

CONDENSER FANS - DIRECT DRIVE PROPELLER TYPE

Number Of Fans - Fan Diameter, In. (mm) 2 – 26 (660) 2 – 26 (660) 2 – 26 (660) Number Of Motors - HP (kW) 2 – 1.0 (0.75) 2 – 1.0 (0.75) 2 – 1.0 (0.75) Fan And Motor RPM, 60 Hz 1140 1140 1140 60 Hz Total Unit Airflow, CFM (l/s) 13950 (6584) 13950 (6584) 12000 (5664)

DIRECT EXPANSION EVAPORATOR - BRAZED PLATE-TO-PLATE

Connection Size Victaul i c, In. (mm) 2 (51) 2 (51) 2 (51) Water Volume, Gallons (L) .94 (3.6) 1.66 (6.3) 2.00 (7.6) Maximum Refrigerant Working Pressure, psig (k P a) 450 (3103) 450 (3103) 450 (3103) Maximum Water P ressure, psig (kPa) 350 (2413) 350 (2413) 350 (2413)

NOTE:

Nominal capacity based on 95°F ambient air and 54°F/44°F water range.

010A 013A 017A

AGZ MODEL NUMBER

IOMM AGZ1 AGZ 010A through 034A

Table 4, Physical Data, AGZ 020A through 034A

PHYSICAL DATA

BASIC DATA

Unit Capacity @ ARI Conditions (1), Tons (kW) 20.4 (71.4) 22.7 (79.5) 28. 2 (98.7) 34.0 (119.0) Number Of Refrigerant Circuits 1 1 1 1 Unit Operating Charge, R-22, Lb. (kg) 34.0 (15.4) 36.0 (16.3) 47.0 (21.3) 50.0 (22.7) Cabinet Dimensions, LxWxH, In. 106.2x 46.3 x 50.8 106.2x 46.3 x 50.8 106.2x 46.3 x 58.8 106.2x 46.3 x 58.8

Cabinet Dimensions, LxWxH, (mm) Unit Operating Weight, Lbs. (kg) 1620 (735) 1675 (760) 1930 (876) 2180 (990)

Unit Shipping Wei ght, Lbs. (kg) 1700 (772) 1750 (794) 2000 (908) 2230 (1012) Add'l Weight If Copper Finned Coils, Lb. (kg) 350 (159) 350 (159) 435 (197) 435 (197)

COMPRESSORS

Type Scroll Scroll Scroll Scroll Nominal Horsepower 10.0 / 13.0 13.0 / 13.0 15.0 / 15.0 20.0 / 20.0 Oil Charge Per Compressor, Oz. (g) 140 (3969) 140 (3969) 140 (3969) 296 (8392)

CAPACITY REDUCTION STEPS - PERCENT OF COMPRESSOR DISPLACEMENT

Standard Staging 0 – 45 - 100 0 – 50 – 100 0 – 50 – 100 0 – 50 – 100

CONDENSERS - HIGH EFFICIENCY FIN AND TUBE TYPE WITH INTEGRAL SUBCOOLING

Coil Face Area, One of Two Sides, Sq. Ft. (M2) 49.0 (4.6) 49.0 (4.6) 58.3 (5.4) 58.3 (5.4) Finned Height x Finned Length, In. 84 x 84 84 x 84 100 x 84 100 x 84 Finned Height x Finned Length, (mm) (2134) x (2134) (2134) x (2134) (2545 ) x (2134) (2545 ) x (2134) Fins Per Inch x Rows Deep 16 x 2 16 x 2 16 x 3 16 x 3 Pumpdown Capacity lb. (kg) 53.1 (24.0) 53.1 (24.0) 90.7 (41.1) 92.8 (42.0)

CONDENSER FANS - DIRECT DRIVE PROPELLER TYPE

Number Of Fans - Fan Diameter, In. (mm) 3 – 26 (660) 3 – 26 (660) 3 – 26 (660) 3 – 26 (660) Number Of Motors - HP (kW) 3 – 1.0 (0.75) 3 – 1.0 (0.75) 3 – 1.0 (0.75) 3 – 1.0 (0.75) Fan And Motor RPM, 60 Hz 1140 1140 1140 1140 60 Hz Total Unit Airflow, CFM (l/s) 20925 (9877) 20925 (9877) 19800 (9346) 19800 (9346)

DIRECT EXPANSION EVAPORATOR - BRAZED PLATE-TO-PLATE

Connection Size Victaul i c, In. (mm) 2 (51) 2 (51) 2 (51) 2 (51) Water Volume, Gallons (L) 2.16 (8.2) 3.05 (11.5) 4.00 (15.1) 5.55 (21.0) Max. Refrigerant Working Pressure, psig (kPa) 450 (3103) 450 (3103) 450 (3103) 450 (3103) Maximum Water P ressure, psig (kPa) 350 (2413) 350 (2413) 350 (2413) 350 (2413)

NOTE:

Nominal capacity based on 95°F ambient air and 54°F/44°F water range.

020A 025A 029A 034A

(2697) x (1176) x

(1289)

AGZ MODEL NUMBER

(2697) x (1176) x

(1289)

(2697) x (1176) x

(1493)

(2697) x (1176) x

(1493)

AGZ 010A through 034A IOMM AGZ1

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. The control transformer is factory mounted.

If the evaporator heater is on a separate disconnect switch from the main unit power supply, the unit may be shut down without defeating the freeze protection provided by the evaporator heater.

Table 5. AGZ 010A – 034A Electrical Data Single Point

AGZ Unit Size

010A

013A

017A

020A

025A

029A

034A

See "Electrical Notes" on page 18.

Minimum

Volts Hz.

208 54 3 6 1 1.00 (25) 60 70 230 54 3 6 1 1.00 (25) 60 70 460 26 3 10 1 1.00 (25) 30 35 575

208 65 3 6 1 1.00 (25) 80 80 230 65 3 6 1 1.00 (25) 80 80 460 34 3 10 1 1.00 (25) 40 45 575

208 79 3 4 1 1.00 (25) 90 100 230 79 3 4 1 1.00 (25) 90 100 460 41 3 8 1 1.00 (25) 45 50 575

208 103 3 2 1 1.25 (32) 125 125 230 103 3 2 1 1.25 (32) 125 125 460 53 3 6 1 1.00 (25) 60 70 575

208 110 3 2 1 1.25 (32) 125 150 230 110 3 2 1 1.25 (32) 125 150 460 58 3 6 1 1.00 (25) 70 80 575

208 136 3 1/0 1 1.50 (38) 150 175 230 136 3 1/0 1 1.50 (38) 150 175 460 62 3 6 1 1.00 (25) 70 80 575

208 175 3 2/0 1 1.50 (38) 200 225 230 175 3 2/0 1 1.50 (38) 200 225 460 88 3 3 1 1.25 (32) 100 110 575

Circuit

Ampacity

(MCA)

23 3 10 1 1.00 (25) 30 30

27 3 10 1 1.00 (25) 30 35

33 3 10 1 1.00 (25) 40 40

45 3 8 1 1.00 (25) 50 60

48 3 8 1 1.00 (25) 60 60

58 3 6 1 1.00 (25) 70 70

72 3 4 1 1.00 (25) 90 100

Field Wire Hub or HACR Breaker Size

Quantity

Power Supply Field Fuse Size

Wire

Gauge

Quantity

Nominal

Size

In. (mm)

Recommended Maximum

IOMM AGZ1 AGZ 010A through 034A

Table 6, AGZ 010A – 034A Compressor and Condenser Fan Motor Amp Draw

AGZ Unit Size

010A

013A

017A

020A

025A

029A

034A

Volts Hz.

208 18.6 18.6 5.8 2 23.7 156 156 230 18.6 18.6 5.8 2 21.4 156 156 460 9.0 9.0 2.8 2 10.7 75 75 575

208 23.7 23.7 5.8 2 23.7 189 189 230 23.7 23.7 5.8 2 21.4 189 189 460 12.5 12.5 2.8 2 10.7 99 99 575

208 29.9 29.9 5.8 2 23.7 232 232 230 29.9 29.9 5.8 2 21.4 232 232 460 15.3 15.3 2.8 2 10.7 125 125 575

208 33.6 41.0 5.8 3 23.7 278 350 230 33.6 41.0 5.8 3 21.4 278 350 460 16.5 21.8 2.8 3 10.7 127 158 575

208 41.0 41.0 5.8 3 23.7 350 350 230 41.0 41.0 5.8 3 21.4 350 350 460 21.8 21.8 2.8 3 10.7 158 158 575

208 52.6 52.6 5.8 3 23.7 425 425 230 52.6 52.6 5.8 3 21.4 425 425 460 23.7 23.7 2.8 3 10.7 187 187 575

208 70 70 5.8 3 23.7 448 448 230 70 70 5.8 3 21.4 448 448 460 35 35 2.8 3 10.7 225 225 575

Compressors Compressors

No. 1 No. 2

7.4 7.4 3.0 2 11.5 54 54

9.1 9.1 3.0 2 11.5 74 74

11.6 11.6 3.0 2 11.5 100 100

13.7 17.3 3.0 3 11.5 100 125

17.3 17.3 3.0 3 11.5 125 125

21.7 21.7 3.0 3 11.5 148 148

28 28 3.0 3 11.5 180 180

See "Electrical Notes" on page 18.

Rated Load Amps Locked Rotor Amps

Fan

Motor

(Each)

No. of

Fan

Mtrs

Fan

Motor

(Each)

Across-The-Line

No. 1 No. 2

AGZ 010A through 034A IOMM AGZ1

Table 7, AGZ 010A – 034A Field Wiring Data, Single Point Power

AGZ

UNIT

SIZE

010A

013A

017A

020E

025A

029E

034A

NOTES:

1. "Size" is the maximum amperage rating for the terminals or the main electrical device.

2. "Size" is the disconnect part number and not the amperage rating for the terminals or the main electrical device.

3. "Connection" is the range of wire sizes that the terminals on the electrical device will accept.

See page 18 for additional Electrical Notes.

Volts HZ.

208 175 14 GA – 2/0 100 8 GA – 2/0 230 175 14 GA – 2/0 100 8 GA – 2/0 460 175 14 GA – 2/0 63 14 GA – 1 GA 575

208 175 14 GA – 2/0 100 8 GA – 2/0 230 175 14 GA – 2/0 100 8 GA – 2/0 460 175 14 GA – 2/0 45 14 GA – 4 GA 575

208 175 14 GA – 2/0 175 6GA – 300 kcmil 230 175 14 GA – 2/0 175 6GA – 300 kcmil 460 175 14 GA – 2/0 45 14 GA – 4 GA 575

208 175 14 GA – 2/0 200 6GA – 300 kcmil 230 175 14 GA – 2/0 200 6GA – 300 kcmil 460 175 14 GA – 2/0 160 8 GA – 1/0 575

208 335 6 GA – 400 kcmil N/A ----230 335 6 GA – 400 kcmil 200 6GA – 300 kcmi l 460 175 14 GA – 2/0 175 6GA – 300 kcmil 575

Standard Power Block Terminal

Maximum

Terminal Amps (1)

175 14 GA – 2/0 63 14 GA – 1 GA

175 14 GA – 2/0 160 8 GA – 1/0

175 14 GA – 2/0 175 6GA – 300 kcmil

Wiring to

Connector Wire Range (Copper Wire Only) (3)

Optional Disconnect Switch

Disconnect

Size (2)

Wiring to

Connector Wire Range

(Copper Wire Only) (3)

IOMM AGZ1 AGZ 010A through 034A

Notes for “Electrical Data Single Point"

1. Field Fuse Size for recommended and maximum is based on use of a time-delay fuse.

2. 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.

3. Since the control transformer is furnished, no separate 115v power is required.

4. If a separate 115V power supply is used for the control circuit, then the wire sizing amps is 2 Amps.

5. Recommended power lead wire sizes for 3 conductors per conduit are based on 100% conductor 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.

6. Single conductors should be used for power connections as listed under “Recommended Power Lead Wire Size.”

7. “Recommended Fuse Sizes” are selected at approximately 150% to 225% of the largest compressor RLA, plus 100% of all other loads in the circuit.

8. “Maximum Fuse Sizes” are selected at approximately 225% of the largest compressor RLA, plus 100% of all other loads in the circuit.

9. The recommended power lead wire sizes are based on an ambient temperature of 86°F. Ampacity correction factors must be applied for other ambient temperatures. Refer to the National Electrical Code Handbook.

Power Limitations:

1. Voltage within 10% of nameplate rating.

2. Phase imbalance within 3%.

Notes for “Compressor and Condenser Fan Amp Draw”:

1. Compressor RLA values are for wiring sizing purposes only but do not reflect normal operating current draw at rated capacity.

Notes for “Field Wiring Data” - Single Point Power:

1. Single point power supply requires a single disconnect to supply electrical power to the unit. This power must be fused.

2. All field wiring to unit power block or non-fused disconnect switch must be copper.

3. All field wire size values given in table apply to 75°C rated wire per NEC.

AGZ 010A through 034A IOMM AGZ1

Figure 7, AGZ 010A through AGZ 034A, Typical Field Wiring Diagram

(BY OTHERS OR

FACTORY OPTION)

3 PHASE

POWER

SUPPLY

OPTIONAL REMOTE

120 VAC CONTROL POWER

SEPARATE EVAPORATOR

HEATER POWER

OPTION

120VAC

(BY OTHERS)

ALARM BELL

OPTION

REMOTE STOP

(BY OTHERS)

CHW FLOW SWITCH

--MANDATORY-(BY OTHERS)

DISCONNECT

(BY OTHERS)

DISCONNECT

(BY OTHERS)

FIELD WIRED

ALARM BELL

RELAY

TIME

CLOCK

UNIT MAIN

TERMINAL BLOCK

FUSED CONTROL

CIRCUIT TRANSFORMER

10A

FUSE

(BY OTHERS)

10A

FUSE

(BY OTHERS)

CHW PUMP RELAY

(BY OTHERS)

120 VAC 1.0 AMPS MAX

OFF

AUTO

MANUAL

GND LUG

TO COMPRESSOR(S)

AND FAN MOTORS

120 VAC

TB1-20

TB1

CONTROL CIRCUIT

FUSE

2 6

TB2

GND

IF REMOTE STOP CONTROL

843

IS USED, REMOVE LEAD 843

IF SEPARATE EVAPORATOR

HEATER POWER OPTION

FROM TERM 25 TO 35.

IS USED - REMOVE MECHANICAL JUMPER BETWEEN TB1-5 AND

TB1-6 & TB1-15 AND

120 VAC

TB1-16

NOR. OPEN PUMP AUX. CONTACTS (OPTIONA L)

4-20 MA FOR

CHW RESET

(BY OTHERS)

OFF

AUTO

ICE MODE SWITCH

(BY OTHERS)

330258401

MANUAL

Rx-/Tx-

Rx+/Tx+

GND

Note: See control and power wiring diagrams on unit control panel for specific unit information.

IOMM AGZ1 AGZ 010A through 034A

J11

GND

COMMUNICATION

PORT

Dimensional Data

Figure 8, AGZ 010A through 017A

5.11 (129.79)

0.875 (22.23)

POWER ENTRY KNOCKOUT (OTHER SIDE)

0.875

(22.23) CONTROL ELECTRICAL KNOCKOUT

39.63

(1006.6)

24.00

(609.6)

3.88 (98.55) MOUNTING HOLES QTY. 4 01.00

AIR

FLOW

ACCESS PANEL

14.59

(370.59)

AGZ

Unit Size

3.00 (78.20) QTY. 2

EVAP.

INLET EVAP. OUTLET

(286.26)

11.27

31.70

(805.18)

49.06

73.57

(1868.68)

(1246.12)

(1173.48)

46.20

21.12

(536.45)

Center of Gravity

Inches (mm)

XYZ AGZ 010 27.8 (706.1) 22.7 (576.6) 19.2 (487.7) 2 AGZ 013 24.3 (617.2) 22.5 (571.5) 19.1 (485.1) 2

AGZ 017 24.4 (619.8) 22.4 (569.0) 19.1 (485.1) 2

Figure 9, AGZ 020A through 034A

46.14

AIR

(1171.96)

FLOW

CONTROL

PANEL

ACCESS

DOORS

ACCESS DOOR

30.91

(785.11)

MOUNTING

HOLES

7.75

(196.85)

Evaporator Connection

Size

Inch Victaulic

POWER ENTRY

AIR

FLOW

51.00

(1295.40)

ACCESS PANEL

AGZ

Unit Size

14.59

(370.59)

3.00

(76.20)

QTY. 2

EVAP. INLET

EVAP.

OUTLET

11.27

(286.26)

31.70

(805.18)

49.0

(1246.12)

MOUNTING HOLES

QTY. 6 01.00 (25.40)

Dimensions

Inches (mm)

106.15

(2696.21)

49.06

(1246.12)

(1173.48)

5.11 (129.79)

46.20

21.12

(536.45)

0.875 (22.23)

POWER ENTRY

KNOCKOUT

(OTHER SIDE)

0.875

(22.23) CONTROL ELECTRICAL KNOCKOUT

3.88

AIR

FLOW

(98.55)

Center of Gravity

Inches (mm)

AB C XY Z

AIR

FLOW

CONTROL

PANE L

ACCESS

DOORS

ACCESS DOOR

30.91

(785.11)

MOUNTING

HOLES

AGZ 020 24.0 (609. 6) 39.6 (1006.6) 51.0 (1295.4) 33.8 (858.5) 22.4 (569.0) 20.2 (513.1) 2 AGZ 025 24.0 (609. 6) 39.6 (1006.6) 51.0 (1295.4) 33.7 (856.0) 22.2 (564.0) 20.1 (510.5) 2 AGZ 029 33.0 (838. 2) 47.6 (1209.8) 59.0 (1498.6) 36.5 (927.1) 23.1 (586.7) 22.6 (574.0) 2 AGZ 034 33.0 (838. 2) 47.6 (1209.6) 59.0 (1498.6) 35.0 (889.0) 23.1 (586.7) 21.4 (543.6) 2

46.14

(1171.96)

POWER

ENTRY

AIR

FLOW

7.75

(196.85)

Evaporator

Connection Size

Inch Victaulic

AGZ 010A through 034A IOMM AGZ1

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 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.

Electrical Terminals

WARNING

Electric shock hazard. Turn off all power before continuing with following service.

Normal heating and cooling of the wire will cause terminals to loosen. Retighten all power electrical terminals every six months.

Condensers

Condensers are air-cooled and constructed with 3/8” (9.5mm) O.D. internally finned copper tubes bonded in a staggered pattern into slit aluminum fins. No maintenance is ordinarily required except the occasional removal of dirt and debris from the outside surface of the fins. Use locally purchased foaming condenser coil cleaners for periodic cleaning of the coil. Condenser cleaners may contain harmful chemicals, be careful when using cleaners. Care should be taken not to damage the fins during cleaning. All chemical cleaners sho uld be thoroughly ri nsed from the coils.

Refrigerant Sightglass

Observe the refrigerant sightglass monthly. A clear glass of liquid indicates adequate sub-cooled refrigerant charge in the system to ensure proper feed through the expansion valve. Bubbling refrigerant in the sightglass indicates the system is short of refrigerant charge. Sub-cooling should be verified to prevent overcharging. Refrigerant gas flashing in the sightglass could also indicate an excessive pressure drop in the line, possibly due to a clogged filter-drier or a restriction elsewhere in the system. 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 or oil should be tested for moisture.

IOMM AGZ1 AGZ 010A through 034A

Standard MicroTech II Controller

Overview............................................................................. 23

General Description............................................................. 23

Compressor Motor Description.......................................23

FanTrol Head Pressure Control .......................................23

Inputs/Outputs................................................................ 24

Setpoints ........................................................................24

Equipment Protection Alarms......................................... 26

Limit Alarms..................................................................26

Unit Enable ....................................................................26

Unit Mode Selection .......................................................27

Low Ambient Start .........................................................27

Automatic Adjusted Range Limits..................................28

Compressor Staging Parameters......................................28

Using the Controller ............................................................30

Display and Keyboard.....................................................30

Getting Started.....................................................................30

Menu Screens.................................................................31

Menu Matrix ..................................................................33

View Screens Defined.....................................................34

Alarm Screens Defined...................................................36

Set Screens Defined........................................................36

AGZ 010A through 034A IOMM AGZ1

Overview

MicroTech II’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.

Operator-friendly

The MicroTech II menu structure is separated into three distinct categories, which provide the operator or service technician with a full description of current unit status, control parameters, and alarms. Security protection prevents unauthorized changing of the setpoints and control parameters.

MicroTech II continuously performs self-diagnostic checks, monitoring system temperatures, pressures and protection devices, and will automatically shut down a compressor or the entire unit should a fault occur. The cause of the shutdown will be retained in memory and can be easily displayed in plain English for operator review. T he MicroTech II chiller controller will also retain and display the time the fault occurred. In addition to displaying alarm diagnostics, the MicroTech II chiller controller also provides the operator with a warning of limit (pre-alarm) conditions.

Staging

The two scroll compressors are staged on and off as a function of leaving chilled water temperature. Lead/lag is automatic and switched every ten starts.

General Description

Compressor Motor Protection

AGZ 013 – 034:

off” relay utilizing the bleed-down capacitor principle. Any time the protection system opens or power to the module is interrupted, the 2-minute “time-off” delay is triggered and the module will not reset for two minutes. Once the 2-minute period has passed the motor protector contacts M1 and M2 reset, provided the protection system is satisfied and power is applied to the module.

Note:

If the power circuit is broken onc e the 2-minute period is passed, the pilot circuit will

reset without delay when power is reapplied.

AGZ 010:

The solid-state compressor motor protector module incorporates a 2-minute “time-

The model AGZ 010 compressor has internal line breakage with automatic reset.

FanTrol Head Pressure Control

FanTrol is the standard method of head pressure control that automatically cycles the condenser fan motors in response to condenser pressure. This function is controlled by the microprocessor, maintains head pressure and allows the unit to run at low ambient air temperatures down to 35°F (1.7°C). Fans are staged as follows:

Table 8, Fan Staging Pressures

Fan Two-Fan Unit Three-Fan Unit

Stage #1 On 150 psig, Off with unit 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 AGZ1 AGZ 010A through 034A

Inputs/Outputs

Table 9, Inputs and Outputs

Analog Inputs

# Description Signal Source Range

1 Reset of Leaving Water Temperature 4-20 mA Current 0-(10 to 80°F) 2 Evaporator Refrigerant Pres sure 0.1 to 0.9 VDC 0 to 132 psi 3 Condenser Refrigerant Pressure 0.1 to 0.9 V DC 3.6to 410 psi 4 Leaving Evaporator Water Temperature 5 Outside Ambi ent Temperature

Thermister (10k at 77°F, 25°C) Thermister (10k at 77°F, 25°C)

Analog Outputs

# Description Output Signal Range

1 None

Digital Inputs

# Description Signal Signal

1 Unit OFF Switch 0 VAC (Stop) 24 VAC (Auto) 2 Remote Start / Stop 0 VAC (Stop) 24 VAC (Start) 3 Evaporator W at er Fl ow Switch 0 VAC (No Flow) 24 VAC (Flow) 4 Motor Protection 0 VAC (Fault) 24 VAC (No Fault) 5 Ice Mode Switch 0 VAC (Normal ) 24 VAC (Ice ) 6 Phase Voltage Fault 0 VAC (Fault) 24 VAC (No Fault) 7 Open 8 Open

Digital Outputs

# Description Load Output OFF Output ON

1 Alarm Alarm Indicator Alarm OFF Alarm ON 2 Evaporator W ater Pump Pump Contac tor Pump OFF Pump ON 3 Liquid Line Solenoid Cool i ng OFF Cooling ON 4 Motor Control Relay #1 Starter Compressor OFF Compressor ON 5 Motor Control Relay #2 Starter Compressor OFF Compressor ON 6 Condenser Fan #1 Fan Contactor Fan OFF Fan ON 7 Condenser Fan #2 Fan Contactor Fan OFF Fan ON 8 Condenser Fan #3 Fan Contactor Fan OFF Fan ON

-58 to 212°F

Setpoints

The setpoints shown in Table 10 are battery-backed and remembered during power off, are factory set to the

Default

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.

value, and can be adjusted within the value shown in the

AGZ 010A through 034A IOMM AGZ1

Range

column.

Table 10, Setpoints

Description Default Range PW Unit

Unit Enable OFF OFF, ON O

Unit Mode COOL

Control Source SWITCHES

Available Modes COOL

Display Units Language ENGLISH ENGLISH, O Evap LWT (COOL & GLYCOL) Ice LWT (ICE) Evap Delta T Startup Delta T * Condenser Fans Stages 2 2,3 M * Phase Voltage Protecti on N N,Y M * SpeedTrol Option N N,Y M

Staging

Stage Up Delay 120 20 to 240 sec M Stage Down Delay 30 10 to 60 sec M

Timers

Evap Flow Proof 5 sec 3 to 120 sec M Low Evap Pressure Delay 30 sec 15 sec to 30sec M Start-Start 15 min 10 t o 60 min M Stop-Start 5 min 3 to 20 min M

Alarms

Evaporator Freeze Low Evap Pressure 58 psi 30 to 60 psi M Low Evap Pressure-Hold 59 psi 31 to 65 psi M Low Evap Pressure-Unload 59 psi 31 to 65 psi M High Condenser Stage Down 370 psi 365 to 375 psi M High Condenser Pressure 380 psi 380 to 390 psi M * Low Ambient Lockout

Condenser Fans

Fan Stages 2 2-3 Stage #1 On 150psi 140 to 200 psi M Stage #2 On 290 psi 230 to 330 psi M Stage #3 On 310 psi 230 to 330 psi M Stage #1 Off Off Off with Stage #1 M Stage #2 Off 170 psi 150 to 200 psi M Stage #3 Off 180 psi 150 to 200 psi M

Sensor Offsets

Evaporator Refrig Press Sensor Offset 00.0 psi -20.0 to 20. 0 psi Condenser Refrig Press Sensor Of fset 00.0 psi -20.0 to 20.0 ps i Leaving Evaporator Water Temp Sensor Outside Ambient Temperature Sensor

(*) These items are factory set prior to shipment.

F/psi

44. 0°F 20.0 to 60.0 °F

40. 0°F 20.0 to 40.0 °F

10. 0°F 6.0 to 16.0 °F

2.0°F 1.0 to 10.0 °F

36.0 °F 18 to 42 °F

35.0 °F –2 to 60 °F

0.0 °F -5.0 t o 5.0 °F

COOL COOL w/Glycol ICE w/Glycol TEST SWITCHES, KEYPAD, NETWORK COOL COOL w/GLYCOL COOL/ICE w/GLYCOL TEST

F/psi

O O O O

IOMM AGZ1 AGZ 010A through 034A

Equipment Protection Alarms

Equipment protection alarms execute rapid compressor shutdown. The following table identifies each equipment protection alarm, gives the condition that causes the

alarm to occur, and states the action taken because of the alarm. 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.

Table 11, Shutdown Alarms

Description Occurs When:

No Evaporator Water Flow

Low Evaporator Pressure

High Condenser Pressure Motor Protection Phase Voltage Protecti on

(opt) Low Ambient Restart Fault

Evaporator Freeze Protect Evap LWT < Evaporator Freeze SP Rapid Stop Manual Leaving Evaporator Water Temperature Sensor Fault Evaporator Pressure Sensor Fault Condenser Pressure Sensor Fault Outside Ambient Temperature Sensor Fault

NOTE: SP=SetPoint

Evap Pump State = RUN and Flow Switch Digital Input = No Flow and time greater t han Evap Flow Proof SP Evaporator Press < Low Evap Pressure SP start Low Evap Pressure Time Delay – if after Ti me Delay if Evap Press > SP c ontinue else stop Condenser Press > High Condenser Pressure SP Digital Input = High Motor Temperat ure On Power Up – Delay 150 Sec. before checking

If Phase Voltage Protection = Y, Then Digital Input = Phase/Voltage Probl em

Failed three consecutive low ambient start attempts

Sensor shorted or open Rapid Stop Manual Sensor shorted or open Rapid Stop Manual Sensor shorted or open Rapid Stop Manual Sensor is open or shorted Rapid Stop Manual

Action

Taken

Rapid Stop

Rapid Stop Manual

Rapid Stop Manual Rapid Stop Manual

Rapid Stop

Rapid Stop Manual

Reset

Flow Switch

Closes

Phase/Voltage

Input Returns

to Normal

Limit Alarms

The following alarms 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 12, Limit Alarms

Description Occurs When: Action Taken Reset

Condenser Pressure Stage Down Low Ambient Lockout

Low Evaporator Pressure – Hold Low Evaporator Pressure – Unload

NOTE: SP = Set Point

Pressure > High Condenser Stage Down setpoint Any compressor is running AND Outside Ambient < Low Amb Lockout SP Pressure < Low Evap Pressure–Hold setpoint Pressure < Low Evap Pressure– Unload setpoint

Shutoff Stage #2 Shutoff Stages #1 & #2

Hold @ Stage 1 Shutoff Stage 2

Condenser Press drops below (SP – 100psi) Outside Ambient > Low Amb Lockout (SP + 5ºF) Evap Press rises above (SP + 8psi) Evap Press rises above (SP + 10 psi)

Unit Enable

Enabling and disabling the chiller is controlled by the Unit Enable Setpoint with options of OFF and ON. This setpoint can be altered by the Unit Off Input, Remote Input, keypad entry, or BAS request. The Control Source setpoint determines which source can change the Unit Enable setpoint with options of SWITCHES, KEYPAD, or NETWORK

Changing the Unit Enable Setpoint can be accomplished according to the following table.

AGZ 010A through 034A IOMM AGZ1

Table 13, Unit Enable Conditions

Unit Off

Input

OFFxxxxOFF

x SWITCHES OFF x x OFF ON SWITCHES ON x x ON ON KEYPAD X OFF x OFF ON KEYPAD X ON x ON ON NETWORK x x OFF OFF

On NETWORK OFF x x OFF

ON NETWORK ON x ON ON

NOTE: An “x” indicates that the value is ignored

Control Source

Set Point

Remote Input Keypad Entry BAS Request Enable

Unit Mode Selection

The overall operating mode of the chiller is set by the Unit Mode Setpoint with options of COOL, COOL w/Glycol, ICE w/Glycol, and TEST. This mode setting can be altered by the keypad, BAS, and Mode input. Changes to the Unit Mode Set Point are controlled by two additional setpoints.

•

Available Modes Setpoint: Determines the operational modes available at any time with options of COOL, COOL w/Glycol, COOL/ICE w/Glycol, and TEST.

•

Control Source Setpoint: Determines the source that can change the Unit Mode Set Point with options of KEYPAD, NETWORK, or SWITCHES.

Changing the Unit Mode Setpoint can be accomplished according to the following table.

Table 14, Unit Mode Selection

Control Source

Set Point

x x x x COOL COOL

x x x x COOL w/Glycol COOL w/Glycol SWITCHES OFF x x COOL/ICE w/Glycol COOL w/Glycol SWITCHES ON x x COOL/ICE w/Glycol ICE w/Glycol

KEYPAD x COOL w/Glycol x COOL/ICE w/Glycol COOL w/Glycol

KEYPAD x ICE w/Glycol x COOL/ICE w/Glycol ICE w/Glycol NETWORK x x COOL COOL/ICE w/Glycol COOL w/Glycol NETWORK x x ICE COOL/ICE w/Glycol ICE w/Glycol

x x x x TEST TEST

NOTE: An “x” indicates that the value is ignored.

Mode

Input

Keypad Entry

BAS

Request

Available Modes

Set Point

Unit Mode

Low Ambient Start

If SpeedTrol = N, the unit will start in the normal operation. If the SpeedTrol = Y then starting will follow table below. This step will bypass the “Low Evaporator Pressure” alarm until Low Ambient Start is completed.

Low Ambient Start Method

Table 15, Low Ambient Start Sequence

Description Occurs When: Action Taken

Check #1 Check #2 Check #3

Check #4

Low Ambient Restart

If the Evap Pressure fails during the low-ambient start, the controller will wait until the anti-cycle timers expire then try to restart. It will allow unit to attempt to start 3 times. If the unit starts successfully, the counter is reset. If it fails to start on the third attempt, the Low Ambient Restart Alarm Fault (Manual Reset) will be activated.

IOMM AGZ1 AGZ 010A through 034A

After 15 Seconds after starting Lead Compressor, I f the Evap Press is < 28 take Action or else continue After 15 Seconds after Check #1, If the Evap Press is < 38 take Action or else c ontinue After 15 Seconds after Check #2, If the Evap Press is < 48 take Action or else c ontinue After 15 Seconds after Check #3, If the Evap Press i s < Low Evap Pressure SP take Act i on or el se continue in normal operation

Rapid Stop – See Low Ambient Re-Start below Rapid Stop – See Low Ambient Re-Start below Rapid Stop – See Low Ambient Re-Start below Rapid Stop – See Low Ambient Re-Start below

Automatic Adjusted Limits

The following setpoint ranges will be adjusted automatically based on selected options or mode of operation.

Evaporator Leaving Water Temperature

Mode Range Unit Mode = Cool Unit Mode = Cool w/ Gycol

Evaporator Freeze Temperature

Mode Range Unit Mode = Cool Unit Mode = Cool w/Glycol, Ice w/ Glycol

Low Evaporator Pressure

Mode Range Unit Mode = Cool 55 to 60 Psig Unit Mode = Cool w/Glycol, Ice w/ Glycol

Low Evaporator Pressure Hold and Unload

Mode Range Unit Mode = Cool 55 to 65 Psig Unit Mode = Cool w/Glycol, Ice w/ Glycol

40 to 60°F 20 to 60°F

36 to 42°F 18 to 42°F

30 to 60 Psig

31 to 65 Psig

Low Ambient Lockout Temperature

SpeedTrol Range SpeedTrol = N SpeedTrol = Y

35– 60°F

-2 – 60°F

Compressor Staging Parameters

The following table gives the rules for staging the two compressors. This is further explained in the MENU section of the manual.

Cool, Glycol

Description Occurs When: Action Taken

Stage #1 ON Stage #2 ON Stage #2 OFF Stage #1 OFF

Note: CB (Control Band) = Evap W ater Delta T x .6

ICE

In ICE mode, the controller stages ON the compressors to stage 2 as shown above until the LWT is < the ICE LWT SP. At this point compressors #1 and #2 shut down simultaneously.

Lvg Evap T > Evap LWT SP + (CB/2) + Startup Delta T After Stage Up Delay times out then, LVG Evap T > Evap LWT SP + (CB/2) After Stage Down Delay times out then, LVG Evap T < Evap LWT SP - (CB/2) After Stage Down Delay times out then, LVG Evap T < Evap LWT SP - (CB/2)

Lead Compressor ON Lag Compressor ON Lag Compressor OFF Lead Compressor OFF

Compressor Lead/ Lag

The compressor designated as the lead will be the first to start and the last to shut off. Lead/lag designation is switched based on the number of starts. After 10 starts on Compressor #1 as lead, Compressor #2 starts as Lead for 10 starts, and then the cycle is repeated.

AGZ 010A through 034A IOMM AGZ1

Capacity Overrides

The following conditions will override the capacity control when the chiller is in the cool and ice modes.

Low Evaporator Pressure

If the unit is running at stage 1 and the evaporator pressure drops below the Low Evaporator Pressure-Hold setpoint, the unit will hold at stage 1. This condition will inhibit the unit from loading until the evaporator pressure reaches the hold setpoint plus 8 psi.

If the unit is running at stage 2 and the evaporator pressure drops below the Low Evaporator Pressure-Unload setpoint, the unit will unload to stage 1. This condition will inhibit the unit from loading until the evaporator pressure reaches the hold setpoint plus 10 psi.

Maximum LWT Rate

The maximum rate at which the leaving water temperature can drop shall be limited at all times by the Maxi mum Rate s etpoi nt (2°F/Minute). If the rate exceeds this setpoint, capacity increases shall be held at Stage 1. This limit is no t adjusta ble through t he keypad and d oes not have a presenc e in any alarm menu.

Discharge Pressure Stage Down

If the unit is running at stage 2 and the condenser pressure rise s above the High Co ndenser Pre ssure Stage Down setpoint, the unit will unload to stage 1. This condition will inhibit the unit from loading until the condenser pressure drops below the unload setpoint less 100 psi.

Digital Output Control

Each digital output is controlled according to the following rules and in accordance with whether the unit is in normal operation or TEST (test mode). All outputs are initialized to OFF at power on.

Alarm – (J12 – NO1)

This output is turned ON when any “EQUIPMENT PROTECTION ALARMS” occur. It is turned OFF when all alarms have been cleared.

Evaporator Pump – (J12 – NO2)

The Evaporator Water Pump output is ON if the Evap State is set to START or RUN.

Liquid Line Solenoid – (J12 – NO3)

This output is ON when the Compressors are ON. It is OFF for all other cases.

Motor Control Relay #1, #2 – (J13 – NO4, J13 – NO5)

This output is ON when the Compressors are ON. It is OFF for all other cases.

Fan #1, #2, & #3 – (J13 – NO6, J14 – NO7, J15 – NO8)

Condenser Fans Staging is based on Condenser pressure as selected Fan Stage On & Off setpoints.

Evaporator Water Pump State Control (Evap State)

The state-transition diagram

Power ON

Unit =OFF or Unit =ALARM

TEST:

RUN

OFF

Unit Enable =

TEST:

OFF

Flow OK for

TEST:

30 Seconds

Unit Enable = ON

TEST:

START

shown to the left controls operation of the evaporator pump. A state variable (Evap State) shall be used to maintain the current state (OFF, START, or RUN). The 30-second timer shall start when flow is first indicated by the Evaporator Water Flow Switch digital input. This timer will reset if flow is lost before reaching 30 seconds, and it will restart when flow is again detected.

IOMM AGZ1 AGZ 010A through 034A

After flow has been present for 30 seconds, the pump state can transition to RUN. In this state, flow has been established so the “No Evap Water Flow” alarm will be active if the flow switch input is OFF for more than the Evap Flow Proof time. The pump remains in the RUN state until the unit status equals off or alarm.

Using the Controller

4x20 Display & Keypad

Layout

The 4-line by 20-character/line liquid crystal display and 6-key keypad are shown below.

Figure 10, Display (in MENU mode) and Keypad Layout

Key to Screen Pathway

Air Conditioning

ALARM

VIEW

< <

ARROW Keys

Note that each ARROW key has a pathway to a line in the display. Pressing an ARROW key will activate the associated line when in the MENU mode.

SET

MENU Key

ENTER Key

Getting Started

There are two basic procedures to learn in order to utilize the MicroTech II controller:

1. Navigating through the menu matrix to reach a desired menu screen and knowing where a particular screen is located.

2. Knowing what is contained in a menu screen and how to read that information or how to change a setpoint contained in the menu screen.

Navigating Through the Menus

The menus are arranged in a matrix of screens across a top horizontal row. Some of these top-level screens have sub-screens located under them. The general content of each screen and its location in the matrix are shown in Figure 12. A detailed description of each menu begins on page 33.

There are two ways to navigate through the menu matrix to reach a desired menu screen. One is to scroll through the matrix fro m one screen to another using the four ARROW keys. The other way is to use shortcuts to work through the matrix hierarchy. From any menu screen,

pressing the MENU key will take you to the top level of the hierarchy. The display will show 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.

AGZ 010A through 034A IOMM AGZ1

For example, selecting ALARM will go the next row of menus under ALARM (ALARM LOG or ACTIVE ALARM). Selecting VIEW will go the next level of screens under VIEW (VIEW UNIT STATUS or VIEW UNIT TEMP). Selecting SET will go to a series of screens for looking at and changing setpoints.

MENU Key

The MENU key is used to switch between the shortcut method (known as the MENU mode and as shown in Figure 10) and scrolling method (known as the SCROLL mode). The MENU mode is the shortcut to spec ific groups o f menus used for checking ALARMS, for VIEWI NG information, o r to SET setpoint values. The SCROLL mode allows the user to move about the matrix (from one menu to another, o ne at a t ime) by using the four ARROW keys. A typical menu scre en is shown in Figur e

11. Pressing the MENU key from any menu screen will automatically return you to the MENU mode as

shown in Figure 10.

Figure 11, Display in the Shortcut (SCROLL) Mode and Keypad Layout

MENU Key

Air Conditioning

VIEW UNIT STATUS Unit = COOL Compr. #1/#2=OFF/OFF Evap Pump = RUN

ARROW Keys

ENTER Key

Menu Screens

Various menus are shown in the controller display. Each menu screen shows specific information; in some cases menus are used only to view the status of the unit, in some cases they are used for checking and clearing alarms, and in some case they are used to set setpoint values.

The ARROW keys on the c ontrol ler ar e used to navigate t hrough t he menus. The keys are also used to change numerical setpoint values contained in certain menus.

Changing Setpoints

Pressing the ENT ER key changes the function of the ARROW keys to the ed iting functi on as sho wn below:

LEFT key Default, changes a value to the factory-set default value. RIGHT key Cancel, cancels any change made to a value and returns to the original setting. UP key Increment, increases the value of the setting

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).

IOMM AGZ1 AGZ 010A through 034A

Most menus containing set point values have several different setpo ints shown on one menu. When in a setpoint menu, the ENTER key is used to proceed from the top line to the second line and on downward. The cursor will blink at the entry point for making a change. The ARROW keys (now in the edit mode) are used to change the setpoint as described above. 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 10).

2. Press SET ( t he UP Key) to go to the setpoint menus.

3. Press UNIT SPs (the Right key) to go to setpoints associated with unit operatio n.

4. Press the DOW N key to scroll down thro ugh the setpoint menus to the thi rd menu which contains

Evap LWT=XX.X°F

5. Press the ENTER key to move the cursor down from the top line to the second line in order to make the change.

6. Use the ARROW keys (now in the edit mode as shown above) to change the setting.

7. When the desired value is achieved, press ENTER to enter it. The cursor will automatically move down.

At this point, the following actions can be taken:

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.

AGZ 010A through 034A IOMM AGZ1

Figure 12, Menu Matrix

UNIT COMP REFRIGERANT FANS

STATUS

VIEW UNIT

TEMP

VIEW COMP

#1 STATUS

⇐ Continued ⇐

(Right side of matrix continued from above)

MENUS

"VIEW"

VIEW COMP #2

STATUS

VIEW EVAP/COND PRESS (1)VIEW UNIT

VIEW EVAP APPROACH (2)

"MENU"

VIEW FAN

STAGING

"ALARM"

ALARM LOG (LAST)

TYPE, TIME

ALARM LOG

(NEXT TO LAST)

ALARM LOG

(SECOND TO LAST)

ALARM LOG

LAST 25 SHOWN

MENUS

ACTIVE ALARM

ADDITIONAL

ACTIVE ALARM

CLEAR/VIEW

⇓

(1)

TYPE, TIME

(2)

TYPE, TIME

(3)

SET UNIT SPs, (1)

MODE

SET UNIT SPs, (2)

MODE

COOL/GLYCOL/

ICE SET UNIT SPs, (3) TEMP EVAP LWT

SET UNIT SPs, (4)

MISC

SET UNIT SPs, (5)

CLOCK

SET UNIT SPs, (6)

ENGLISH

SET UNIT SPs, (7)

PROTOCOL

SET UNIT SPs, (8)

EVAP OFFSET

SET UNIT SPs, (9)

COND OFFSET

SET UNIT SPs,

(10) LWT OFFSET

SET UNIT SPs,

(11) AMBIENT

OFFSET

SET UNIT SPs,

(12) ENTER PASSWORD

"SET"

SET COMP

SPs (1)

STOP/START

SET COMP

SPs (2) INTER-

STAGE

MENUS

SET LIMIT ALARMS (1) EVAP PRESS

SET LIMIT ALARMS (2)

FREEZE/ FLOW

SET LIMIT ALARMS (3)

COND PRESS

SET LIMIT ALARMS (4)

PHASE/VOLT

LOW AM B

LOCKOUT

SET LIMIT ALARMS (5)

LOW EV A P PR

SET FANS (1)

STAGES

FANTROL

SET FANS (2)

STAGE ON

SET FANS (3)

STAGE OFF

Menu Structure (Hierarchical)

As discussed previously, a hierarchical menu structure can be used to access the various screens. One to twelve levels are used with two or three being typical. Optionally, the last menu selection can access one of a set of screens that can be navigated with the UP/DOWN ARROW keys (see the scrolled menu struct ure below).

IOMM AGZ1 AGZ 010A through 034A

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. An example follows showing the selection of the “VIEW COMPRESSOR (n) screen.

Suppose the initial screen is as below or any other menu screen:

ALARM LOG (data) (data) (data)

After pressing the

key, the top level menu screen will show:

< ALARM < VIEW < SET

After pressing the “

VIEW

” menu key, a menu screen will show:

VIEW < UNIT < COMPRESSOR < REFRIGRANT < FANS

Selection of any of these will advance to the appropriate data menu. For example, after pressing the “

REFRIGERANT

” menu button, the selected data screen will show:

VIEW REFRIG PSI °°°°F

SAT EVAP XXX.X XX.X SAT COND XXX.X XX.X

The ARROW keys will automatically return to the “scroll” mode at this time.

Screen Definitions VIEW

This section contains information on each screen. The menu screens are in order of the matrix in Figure 12, goi ng from left to right and then down when there are sub-menus. Many menus are selfexplanatory.

VIEW UNIT

VIEW UNIT STATUS Unit = AUTO Compr.#1/#2=OFF/OFF Evap Pump = RUN

Unit states 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.

AGZ 010A through 034A IOMM AGZ1

VIEW UNIT TEMP °°°°F Evap LWT = XX.X°°°°F Outside Amb = XX.X°°°°F LEW Target = XX.X°°°°F

LEW Target is the chilled fluid setpoint. It is the temperature that the controller controls to. Evap LWT is the chilled fluid (usually water) temperature leaving the evaporator..

VIEW COMPRESSORS

VIEW COMP#1 State = OFF LEAD Hours = XXXXX Starts = XXXXX

VIEW COMP#2 State = OFF LAG Hours = XXXXX Starts = XXXXX

VIEW REFRIGERANT

VIEW REFRIG (1) psi °°°°F

SAT EVAP XXX.X XX.X SAT COND XXX.X XX.X

VIEW REFRIG (2) Evap Approach=XX.X°°°°F

Approach is the difference between the leaving fluid temperature and the saturated evaporator temperature. It is an indication of the evaporator efficiency; an increasing approach temperature indicates decreasing heat transfer efficiency

VIEW FANS

VIEW FANS Stages ON = 2 of 3

IOMM AGZ1 AGZ 010A through 034A

Screen Definitions – ALARM

ALARM ACTIVE (X) Alarm Description hh:mm:ss dd/mmm/yyyy

ALARM ACTIVE (X) No more alarms Press ENTER to clear all active alarms

If the unit is off on a shutdown alarm or running but in a limit alarm condition, the ca use and da te will appear in the upper screen. If there is a simultaneous occurrence of more than one alarm, the others will appear in additional screens below this one, accessed by the DOWN ARROW. Either type alarm will light a red light in back of the LEFT-KEY. The light will go out when the fault is cleared.

To clear the fault, scroll down to the last screen and press ENTER. If other faults have appeared, they will all be cleared at the same time.

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 la st 25 o ccurr ences. T he sc reens ar e numbered (1), (2), (3), etc.

Screen Definitions – SET

Changing setpoints;

1. Select the desired menu by scrolling through SET menus with the UP and DOWN ARROWS .

2. When the desired menu is selected, select the desired entry by moving between lines using the ENTER key.

3. If a numerical value is being changed, use the INCREMENT key (UP ARROW) to increase or the DECREMENT key (DOWN ARROW) to decrease the value of the setpoint.

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 setpoi nt options using the UP ARROW key.

4. Enter the desired value or word into the controller by pressing the SET key.

in general, setpoints are changed as follows:

AGZ 010A through 034A IOMM AGZ1

SET UNIT SPs

SET UNIT SPs (1) Unit Enable=OFF Mode=COOL Source=KEYPAD

Unit Enable is an external signal or a keypad setting that keeps the unit off when the setting is OFF and allows it to run if there is a call for cooling. The source for the signal is selected in the 4 and can be:

1. KEYPAD, in which case the selection is made in line 2 and would be normally selected as ON. This is the normal setting when no external signals are controlling the unit.

2. SWITCHES, in which an external switch is wired across terminals #25 and #35. (See wiring diagram page 19).

3. NETWORK, used with BAS signal, which is wired to the three communication ports.

Unit Mode settings can be

1. COOL, normal setting used with chilled water air-condition applications.

2. COOL w/GLYCOL, used with low temperature, glycol applications. It allows a lower LW T setpoint to be used.

3. ICE w/GLYCOL, used with ice storage systems, allows changing from chilled glycol operation to lower temperature ICE operation. In ICE, the unit runs at full load until the ICE setpoint is reached, at which time the unit shuts off. A three-position switch wired to terminals #28 and #38 initiates the change from glycol cooling to making ice. (See wiring diagram on page 19.)

line

SET UNIT SPs (2) 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 front panel (FP) must be in the OFF position before the MODE can be changed. T his prevents a mode change while the unit is operating.

line is a reminder that the ON/OFF switch on the

SET UNIT SPs (3) Evap LWT = XX.X°°°°F Ice LWT = XX.X°°°°F EvapDeltaT= XX.X°°°°F

IOMM AGZ1 AGZ 010A through 034A

SET UNIT SPs (4) StartDelta= XX.X°°°°F

Staging StartDelta is the number of degrees above the temperature setting that determines when the compressor starts. Compressor start and stop is determined by the dead band and StartDelta settings. The dead band is automatically set of 60% of the EvapDeltaT selected in menu 3 above. For example, for settings of:

EvapDelta T = 10°F (Dead Band = 6°F) StartDelta = 2°FLWT = 40°F

lead

EWT

Evap Delta-T Set

LWT Set

setting (default at 30 sec.), the lead compressor will remain on. This would be normal operatio n. If for some reason the temperature does not rise, the lead compressor will also shut off. The lead compressor will start when the chilled water temperature reaches 45°F.

50.0°F

10.0°F

40.0°F

Start Delta-T

45.0°F

43.0°F

½ DB

40.0°F

½ DB

37.0°F

For a warm start-up the lead compressor will start at any temperature above 45°F. T he lag will start after the start interval has timed out. The chilled water temperature will begin to be pulled down. At 37°F the lag compressor will shut off. If the temperature climbs above 37°F within the StageDownTimer

SET UNIT SPs (5) CLOCK dd/mmm/yyyy hh:mm:ss

SET UNIT SPs (6) Units = °°°°F/psi

Lang = ENGLISH

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.

SET UNIT SPs (7) Protocol = NONE Ident Number=001 Baud Rate=9600

Protocol selection for BAS will be available in June 2002.

SET UNIT SPs (8) Evaporator Refrig Press Sensor Offset= 00.0 psi

AGZ 010A through 034A IOMM AGZ1

The pressure offsets on menus 8 and 9 and the temperature offsets on menus 10 and 11 correct the controller's display of the parameters. The sensors used in these units have a high degree of repeatability but may need correction (offset). An accurate pressure gauge or thermometer is used to determine the correct temperature or pressure. A positive or negative offset value is then entered to make the controller reading agree with the measured value.

SET UNIT SPs (9) Condenser Refrig Press Sensor Offset= 00.0 psi

SET UNIT SPs (10) Leaving Evaporator Water Temp Sensor Offset= 00.0oF

SET UNIT SPs (11) Outside Ambient Temperature Sensor Offset= 00.0oF

SET UNIT SPs (12) 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. The Operator Password is 0100. Either password must be entered using the ENTER PASSWORD (12) screen before a protected setting can be changed.

This screen can be accessed either through the SET OT HER menu or by simply pressing the ENT ER key while on one of the SET screens. The controller will automatically go from the screen with the setting change to this screen. After the correct password has been entered, the controller will automatically return to the original set screen.

Once a password has been entered, it remains valid for 15 minutes after the last key-press.

SET COMP SPs

SET COMP SPs (1) Stop-Start =XXmin Start-Start =XXmin

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 recommended that these default values not be changed.

IOMM AGZ1 AGZ 010A through 034A

SET COMP SPs (2) InterStageUp=XXXsec InterStageDn=XXXsec

InterStageUp is the time delay since the last stage change before a compressor can stage on. InterStageDn is the time delay since the last stage change before a compressor can stage off normally

(not by an alarm).

SET LIMIT ALARMS

SET ALARM LMTS (1) LowEvPrHold=XXXpsi LowEvPrUnld=XXXpsi LowEvPrStop=XXXpsi

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 compresso r is running, the LowEvPrH old is in effect and the lag compressor is prevented fr om starting, thereby holding the unit capacity.

The last action to take place is the shutoff of all compressors r unning when the LowEvPrStop setting is reached (default is 58 psi).

SET ALARM LMTS (2) Evap Freeze= XX.X°°°°F

LowEvpPrDelay=XXs EvapFlowProof=XXXsec

Evap Freeze (the unit freeze protection shutdown) is actually a stop alarm and shuts off the unit when the LW T reaches 36°F. It is cleared by going to the CLEAR ALARM menu in the ACTIVE ALARM hierarchy.

LowEvPrDelay is a time delay on the low pressure trip that reduces nuisance low-pressure trips. The default setting is 30 seconds.

EvapFlowProof is the flow switch interlock. Closing the flow switch and therefor proving the existence of chilled water flow resets this trip.

SET ALARM LMTS (3) HighCondPr = XXXpsi HiCondStgDn = XXXpsi

HighCondPr ( the unit high-discharge -pressure shutd own) is a stop ala rm that shuts off the unit when the discharge pressure reaches the setting. 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.

SET ALARM LMTS (3) PhaseVoltage=YES/NO

LowAmbientLock=XX°°°°F

AGZ 010A through 034A IOMM AGZ1

LowAmbientLock prevents unit operation below the setting. If the unit is equipped with the standard FanTrol pressure-activated control, the available range is 35°F to 60°F with a default of 35°F. With the optional SpeedTrol variable speed control, the range becomes –2°F to 60 °F with default of 0°F. Input to line 3 of the next screen, SET FANS SP (1), informs the controller which type of control is installed and which range of setting to allow.

SET FANS STAGES

SET FANS SPs (1) Fans = 2 Speedtrol = NO

The Fans line tells the controller the number of fans on the unit. The UP ARROW toggles between 1, 2, and 3. 1 is not used; 2 should be used for Models AGZ 010, 013, and 017; and 3 should be used for AGZ 020, 025, 029, and 034.

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.

SET FANS SPs (2) Stage ON psi #1 #2 #3 150 290 310

SET FANS SPs (3) Stage Off psi #1 #2 #3 UNIT 170 180

These two menus set the on and off staging pressures for the fans. The left-hand two are for three-fan units, the right-hand two are for two-fan units. 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.

SET FANS SPs (2) Stage ON psi #1 #2 150 290

SET FANS SPs (3) Stage Off psi #1 #2 UNIT 170

Editing, Review

Editing is accomplished by pressing the ENTER key until the desired field is selected. This field is indicated by a blinking cursor under it.. The arrow keys shall then operate as defined below.

CANCEL...................Reset the current field to the value it had when editing began.

DEFAULT.................Set value to original factory setting.

INCREMENT ............Increase the value or select the next item in a list.

DECREMENT ...........Decrease the value or select the previous item in a list.

During edit mode, the display shall show a two-character-wide menu pane on the right as shown below.

SET UNIT SPs (X) <D (data) <C (data) <+ (data) <-

Additional fields can be edited by pressing the ENTER key until the desired field is selected. When the last field is selected, pressing the ENTER key switches the display out of “edit” mode and returns the ARROW keys to “scroll” mode.

IOMM AGZ1 AGZ 010A through 034A

Service

WARNING

Disconnect all power before doing any service inside the unit. Failure to do so can cause

serious personal injury.

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.

Note:

Repeated tripping of safety controls must be investigated and corrected.

Thermostatic Expansion Valve

The expansion valve is responsible for allowing the proper amount of refrigerant to enter the evaporator regardless of cooling load. It does this by maintaining a constant superheat. (Superheat is the difference between refrigerant temperature as it leaves the evaporator and the saturation temperature corresponding to the evaporator pressure.) Typically, superheat should run in the range of 8°F to 12°F (4.4°C to 6.6°C).

The superheat setting can be adjusted by removing the cap at the bottom of the valve to expose the adjustment screw. Turn the screw clockwise (when viewed from the adjustment screw end) to increase the superheat setting and counterclockwise to reduce superheat. Allow time for system rebalance after each superheat adjustment.

The expansion valve, like the solenoid valve, should not normally require replacement, but if it does the unit must be pumped down by following the steps involved when changing a filter-drier.

If the problem can be traced to the power element only, unscrew the element from the valve body without removing the valve, but only after pumping the unit down.

Filter-Driers

If the pressure drop across the filter-drier is in the 6 to 10 psi range, it should be monitored and changed when the pressure drop reaches 10 psi. To change the liquid line sealed filter, de-energize the unit and pump out the refrigerant. After changing the filter-drier, check for leaks before recharging and r eturning unit to operation.

Liquid Line Solenoid

The liquid line solenoid valve does not normally require any maintenance. It may, however, require replacement of the solenoid coil. The solenoid coil may be removed from the valve body without opening the system by disconnecting power to the unit. The coil can then be removed from the valve body by simply removing the nut or snap ring located at the top of the coil.

AGZ 010A through 034A IOMM AGZ1

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.

The SpeedTrol fan motor is a single-phase, 230/460 volt, thermally protected motor specially designed for variable speed operation. The solid-state speed control is mounted in the unit control panel and is connected to a Schrader fitting on the liquid line. The control is factory-set to start modulating fan speed at 230 psig, and it will maintain a minimum condensing pressure of 170 to 180 psig. Minimum starting voltage for SpeedTrol motors is 120 volts.

A low ambient timer function is included in the microprocessor. When the solenoid valve and lead compressor are energized by the controller, the low pressure cutout control is bypassed and the compressor is allowed to start with the low pressure control open.

After about 2-3/4 minutes, the time delay will open and the low pressure cutout function is again operable. I f the system has not built up enough e vapor ator pr essure to close the low pressur e se tting, the compressor will stop.

Due to the vertical condenser design, it is recommended that the unit be oriented so that prevailing winds blow parallel to the unit length, thus minimizing effects on minimum ambient operation. If it is not practical to orient the unit in this manner, a wind deflector should be constructed.

Hot Gas Bypass

Hot gas bypass is a system for maintaining evaporator pressure at or above a minimum value. The purpose for do ing this is to keep the velocity of the refri gerant as it passes through the eva porator high enough for prope r oil return to the compressor when cooling load conditions a re light. It al so maintains continuous operation of the chiller at light load conditions.

The solenoid valve should be wired to open whenever the liquid line solenoid valve is energized. This can be accomplished by wiring the hot gas solenoid (SV5) in parallel with the liquid line solenoid at t erminals 14 and 16. The p ressure-regul ating valve is fac tory-set to begin op ening at 58 PSIG (32°F for R-22) when the air-charged bulb is in an 80°F ambient temperature. The bulb can be mounted anywhere as long as it senses a fairly constant temperature at various load conditions. The compressor suction line is one such mounting location. It is generally in the 50°F to 60°F range.

The chart below indicates that when the bulb is sensing 50°F to 60°F temperatures, the valve will begin opening at 54 PSIG. This setting can be changed as indicated above, by changing the pressure setting, remove the cap on the bulb and turn the adjustment screw clockwise. To lower the setting, turn the screw counterclockwise. Do not force the adjustment beyond the range it is designed for, as this will damage the adjustment assembly.

The regulating valve opening point can be determined by slowly reducing the system load (or increasing the required chiller water temperature setting indicated on the unit thermostat), while observing the suction pressure. 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 AGZ1 AGZ 010A through 034A

WARNING

The hot gas line may become hot enough to cause injury in a very short time, be careful 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.

Figure 13, Hot Gas Bypass Piping

uction Line

Hot Gas Bypass

Solenoid Valve

Adjustable Remote Bul

External Equalizer Connection to Suction Side of Evaporator

Discharge

Line

Hot Gas

Bypass Valve

To Evaporator Inlet After Expansion Valve

Figure 14, Hot Gas Bypass Adjustment

VALVE OPENING PRESSURE (PSIG)

30 40 50 60 70 80 90 100 110

REMOTE BULB ADJUSTMENT RANGE

TEMP (°F) AT BULB LOCATION

RANGE

ADJUSTMENT

AGZ 010A through 034A IOMM AGZ1

Troubleshooting Chart

Table 16, Troubleshooting Chart

PROBLEM POSSIBLE CAUSES POSSIBLE CORRECTIVE STEPS

COMPRESSOR WILL NOT RUN

COMPRESSOR NOISY OR VIBRATING

HIGH DISCHARGE PRESSURE

LOW DISCHARGE PRESSURE

HIGH SUCTION PRESSURE

LOW SUCTION PRESSURE

UNIT WILL NOT LOAD OR UNLOAD LOAD/UNLOAD INTERVAL TOO SHORT

COMPRESSOR LOSES OIL

MOTOR OVERLOAD RELAYS OPEN OR BLOWN FUSES

COMPRESSOR THERMAL SWITCH OPEN

1. Main switch open

2. Fuse blown, breakers open

3. Thermal overloads tripped

4. Defective contactor or coil

5. System off by safety device

6. No cooling required

7. Liquid line solenoid will not open

8. Motor electrical problem

9. Loose wiring

1. Refrigerant flooding compressor

2. Improper line support

3. Worn compressor

1. Noncondensables in system

2. Refrigerant overcharge

3. Fan not running

4. Dirty condenser coils

5. FanTrol out of adjustment

1. Faulty condenser control

2. Low refrigerant charge

3. Low suction pressure

1. Excessive load

2. Expansion valve overfeeding

1. Lack of refrigerant

2. Evaporator dirty

3. Clogged filter-drier

4. Expansion valve malfunctioning

5. Low condensing temperature 1 Faulty controller sensor/broken wire

2. Stages not set for application

1. Erratic water thermostat

2. Insufficient water flow

1. Lack of refrigerant

2. Suction superheat too high

3. Crankcase heater burned out

1. Low voltage during high loads

2. Defective or grounded motor wiring

3. Loose power wiring

4. High condensing temperature

5. Unbalanced voltage

1. Operating beyond design conditions 1. Add facilities so conditions are within allowable limits

1. Close switch

2. Check electrical circuits and motor windings for shorts. Check for overloads and loose connections. Replace fuse or reset breaker.

3. Check unit when back on line, auto reset

4. Repair or replace

5. Determine cause and correct

6. None, should start on call for cooling

7. Repair or replace coil

8. Check motor for open or short circuit, or burnout

9. Check all wire junctions. Tighten all terminals.

1. Check expansion valve setting

2. Relocate or add supports

3. Replace

1. Remove with authorized procedures

2. Remove excess

3. Check electrical circuit

4. Clean coil

5. Adjust FanTrol setting

1. Check condenser control operation

2. Check for leaks. Add refrigerant

3. See low suction pressure steps below

1. Reduce load or add capacity

2. Check remote bulb. Regulate superheat

1. Check for leaks. Repair and replace refrigerant.

2. Clean chemically

3. Replace

4. Check and adjust for proper superheat

5. Check discharge pressure control settings

1. Replace

2. Adjust thermostat setting

1. Replace

2. Adjust flow

1. Check for leaks and repair

2. Adjust superheat

3. Replace crankcase heater

1. Check supply voltage

2. Replace compressor

3. Check all connections and tighten

4. See steps for high discharge pressure

5. Check voltage. Contact power company.

IOMM AGZ1 AGZ 010A through 034A

AGZ 010A through 034A IOMM AGZ1

Post Office Box 2510, Staunton, Virginia 24402 USA • (540) 248-0711 • www.mcquay.com

McQuay AGZ 010A Installation Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

MODEL CODE

Introduction

General Description

Inspection

Installation

Handling

Location

Unit Placement

Service Access

Clearances

Sound Isolation

Vibration Isolators

Corner Weights

Chilled Water System

System Volume

Variable Chilled Water flow

Flow Switch

Water Connections

Refrigerant Charge

Unit Component Location

Glycol Solutions

Evaporator Water Flow and Pressure Drop

Control Layout and Operation

Control Center

Start-up and Shutdown

Pre Start-up

Start-up

Sequence of Operation

Start-Up

Equipment Protection Alarms

Unit Enable Selection

Unit Mode Selection

Condenser fan control

Shutdown

Physical Data

Electrical Data

Field Wiring

Notes for “Electrical Data Single Point"

Power Limitations:

Notes for “Compressor and Condenser Fan Amp Draw”:

Notes for “Field Wiring Data” - Single Point Power:

Dimensional Data

Lubrication

Electrical Terminals

Condensers

Refrigerant Sightglass

Standard MicroTech II Controller

Table of Contents

Overview

Operator-friendly

Staging

General Description

Compressor Motor Protection

FanTrol Head Pressure Control

Inputs/Outputs

Analog Inputs

Setpoints

Equipment Protection Alarms

Limit Alarms

Unit Enable

Unit Mode Selection

Low Ambient Start

Low Ambient Start Method

Low Ambient Restart

Automatic Adjusted Limits

Evaporator Leaving Water Temperature

Compressor Staging Parameters

Compressor Lead/ Lag

Capacity Overrides

Digital Output Control

Evaporator Water Pump State Control (Evap State)

Using the Controller

4x20 Display & Keypad

Getting Started

Navigating Through the Menus

MENU Key