McQuay AGZ 026BH Installation Manual

Installation and Maintenance Manual
IMM AGZ-8
Group: Chiller Part Number: 331374001
Air-Cooled Scroll Compressor Chiller
AGZ 026BS/BH through 130BS/BH R-22, R-407C 60 Hertz
Effective: Supercedes:
July 2007
Table of Contents
Introduction.........................................3
General Description....................................... 3
Inspection....................................................... 3
Nomenclature................................................. 3
Installation ...........................................4
Handling ........................................................ 4
Location......................................................... 5
Vibration Isolators....................................... 12
Ambient Air Temperature Limitations......... 15
Water Piping ................................................ 17
Flow Switch................................................. 19
Water Connections.......................................20
System W ater Volume Considerations......... 20
Variable Speed Pumping.............................. 20
Glycol Solutions .......................................... 20
Operating/Standby Limits............................ 24
Evaporator Flow and Pressure Drop Water
Flow Limitations..........................................
Wind Baffles and Hail Guards..................... 26
24
Optional Features..............................28
Controls ....................................................... 28
BAS Interface .............................................. 28
Remote Operator Interface Panel................. 29
Physical Data, R-22 ...........................31
Physical Data, R-407C ......................36
Electrical Data, R-22.........................41
AGZ BS, Standard Ambient ........................ 41
AGZ-BH, High Ambient ............................. 51
Electrical Data, R-407C....................58
AGZ BS, Standard Ambient ........................ 58
AGZ-BH, High Ambient ............................. 64
Dimensional Data..............................71
R-407C Charging & Service............. 74
Startup................................................ 78
Pre Start-up .................................................. 78
Start-Up........................................................ 78
Shutdown..................................................... 79
Water Piping Checkout ................................79
Refrigerant Piping Checkout........................ 79
Electrical Check Out.................................... 80
Component Operation......................80
Hot Gas Bypass (Optional).......................... 80
VFD Low Ambient Control (Optional)........81
Filter-Driers..................................................81
System Adjustment ......................................81
Liquid Line Sight Glass ............................... 81
Refrigerant Charging....................................81
Thermostatic Expansion Valve ..................... 82
Crankcase Heaters........................................ 82
Evaporator.................................................... 82
Phase Voltage Monitor (Optional) ............... 82
Unit Maintenance.............................. 83
Preventive Maintenance Schedule ...............84
Service ................................................ 85
Liquid Line Solenoid Valve ......................... 85
Evaporator.................................................... 86
Refrigerant Charging....................................86
Warranty Statement..........................87
AGZ Troubleshooting Chart ............
88
Unit controllers are LONMARK certified with an optional LONWORKS communication module.
Manufactured in an ISO Certified
"McQuay" is a registered trademark of McQuay International
Illustrations and data cover McQuay International products at the time of publication and we reserve the right
to make changes in design and construction at anytime without notice.
2 AGZ 026B through 130B IMM AGZ-8
©2005 McQuay International
Introduction

General Description

McQuay Air-Cooled Global Water Chillers are complete, self-contained automatic refrigerating units. Every unit is completely assembled, factory wired, charged, and tested. Each unit consists of twin air-cooled condensers with integral subcooler sections, two tandem or triple scroll compressors, brazed-plate or replaceable tube, dual circuit shell-and-tube evaporator, and complete refrigerant piping. Liquid line components include manual liquid line shutoff valves, sight-glass/moisture indicators, solenoid valves, and thermal expansion valves. Other features include compressor crankcase heaters, an evaporator heater for chilled water freeze protection, limited pumpdown during “on” or “off” periods, automatic compressor lead-lag to alternate the compressor starting sequence, and sequenced starting of compressors.
The electrical control center includes all equipment protection and operating controls necessary for dependable automatic operation. Condenser fan motors are protected in all three phases and started by their own three-pole contactors.

Manuals

This manual covers the installation, maintenance and service for dual circuit, AGZ packaged scroll compressor chillers. Information on remote evaporator units is in IMM ACZ/AGZ-4. Operating information is contained in the operating manual OM AGZ-1.

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, making certain it agrees with the power supply available. McQuay is not responsible for physical damage after the unit leaves the factory.
Note: Unit shipping and operating weights are available in the Physical Data tables beginning on page 31.

Nomenclature

A G Z - XXX B S
Scroll Compressor
Air-Cooled
Global
Application S= Standard Ambient, Packaged M= Standard Ambient, Remote H= High Ambient, Packaged B= High Ambient, Remote
Design Vi ntage
Model Size (Nominal Tons)
IMM AGZ-8 AGZ 026B through 130B 3

Installation

Note: Installation is to be performed by qualified personnel who are familiar
with local codes and regulations.
WARNING
Sharp edges on unit and coil surfaces are a potential hazard to personal safety.
Avoid contact with them.

Handling

Be careful to avoid rough handling of the unit. Do not push or pull the unit from anything other than the base. Block the pushing vehicle away from the unit to prevent damage to the sheet metal cabinet and end frame (see
To lift the unit, 2 1/2" (64mm) diameter lifting tabs are provided on the base of the unit. Arrange spreader bars and cables to prevent damage to the condenser coils or cabinet
Figure 2).
(see
Figure 1, Suggested Pushing Arrangement
Blocking is required across full width
Figure 1).
Figure 2, Suggested Lifting Arrangement
Number of fans may vary
from this diagram. The lifting
Spreader bars
Spreader bars
required
required
(use caution)
(use caution)
method will remain the same.
All rigging locations must be used.
4 AGZ 026B through 130B IMM AGZ-8

Location

Unit Placement

AGZ units are for outdoor applications and can be mounted either on a roof or at ground level. For roof mounted applications, install
Figure 3, Clearances
SEE ATTACHED TABLE
DIMENSION “A”
the unit on a steel channel or I-beam frame to support the unit above the roof. For ground level applications, install the unit on a substantial base that will not settle. A one-
4 FT. (1220mm) CLEARANCE FOR
SERVICE ACCESS
4 FT. (1220) CLEARANCE FOR
SERVICE ACCESS
piece concrete slab with footings extended below the frost line is recommended. Be sure the foundation is level within 1/2" (13mm) over its length and width. It is recommended
SEE ATTACHED TABLE
DIMENSION “A”
that the unit be raised a few inches with suitable supports, located at least under the mounting locations, to allow water to drain from under the unit and to facilitate cleaning under it. The foundation must be strong enough to support the weights listed in the Physical Data Tables beginning on page
31.
Table 1, Recommended Minimum Clearances
Model Size
026B – 070B 075B – 130B
Coil Side “A”
ft (m)
4 (1.2) 8 (2.4) 6 (1.8) 4 (1.2) 4 (1.2) 6 (1.8) 12 (3.6) 8 (2.4) 4 (1.2) 4 (1.2)
“B”
ft (m)
“C”
ft (m)
End Opposite
Controls ft (m)
Control Panel End
ft. (m)

Clearances

Do not block the flow of air to and from the condenser coil. Restricting airflow or allowing air recirculation
AIR
DISCHARGE
will result in a decrease in unit performance and efficiency because discharge pressures are increased. There must be no obstruction above
AIR FLOW AIR FLOW
AIR FLOW
“B”
the unit that would deflect discharge air downward where it could be recirculated back to the inlet of the
The recommended minimum side clearance between two units is dimension “B’ in table on this page.
condenser coil. The condenser fans are propeller type and will not operate with ductwork.
AIR FLOW AIR FLOW
AIR
DISCHARGE
Install the unit with enough side clearance for air to enter the coil and for servicing. Provide service access to the evaporator, compressors,
“C” “C”
electrical control panel and piping components.
Do not allow debris to accumulate near the unit where it could be drawn
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 dimension “C” in table on this page.
into the condenser coil. Keep condenser coils and fan discharge free of snow or other obstructions to permit adequate airflow for proper operation.
AIR
DISCHARGE
IMM AGZ-8 AGZ 026B through 130B 5
Restricted Air Flow General
The clearances required for design-life operation of AGZ air-cooled condensers are described in the previous section. Occasionally, these clearances cannot be maintained due to site restrictions such as units being too close together or a fence or wall restricting airflow, or both.
Fortunately, the McQuay AGZ chillers have several features that can mitigate the problems attributable to restricted airflow.
The condenser section is shaped as shown
Figure 4. This allows inlet air for these coils to come in from either side. A vertical coil and its adjacent angled coil are manifolded together to serve one refrigerant circuit.
The MicroTech II® control is proactive in response to “off-design conditions”. In
the case of single or compounded influences restricting airflow to the unit, the microprocessor will act to keep the compressor(s) running (possibly at reduced capacity) rather than allowing a shut-off on high discharge pressure.
The MicroTech II® control can be programmed to sequence the compressors in the
most advantageous way. For example, in the diagram shown below, it might be desirable to program circuit #1 to be the lag circuit (last circuit to reach full load) during periods of high ambient temperatures.
Figure 4, Coil and Fan Arrangement
Building
Circuit #1 Circuit #2
NOTE: Models AGZ 026 to 035 do not have an interior slanted coil.
The following sections discuss the most common situations of condenser air restriction and give capacity and power adjustment factors for each. Note that in unusually severe conditions, the MicroTech II® controller would adjust the unit operation to remain online until a less severe condition is reached.
6 AGZ 026B through 130B IMM AGZ-8

Case 1, Building or Wall on One Side of One Unit

The existence of a screening wall or the wall of a building in close proximity to an air-cooled chiller is common in both rooftop and ground level applications. Hot air recirculation on the coils adjoining the wall will increase compressor discharge pressure, decreasing capacity and increasing power consumption. Only the compressor(s) connected to these coils will be affected. Circuits opposite the wall are unaffected.
When close to a wall, it is desirable to place chillers on the north or east side of them. It is also desirable to have prevailing winds blowing parallel to the unit’s long axis. The worst case is to have wind blowing hot discharge air into the wall.
Figure 5, Unit Adjacent to Wall
H
Figure 6, Adjustment Factors
3.0
2.0
1.0
.5
D
AGZ
075-130
4.5 ft.
(1.4m)
6 ft.
(1.8m)
8 ft.
(2.4m)
AGZ
026-070
3.5 ft.
(1.0m)
4 ft.
(1.2m)
6 ft.
(1.8m)
4.0
3.0
2.0
AGZ
6 ft.
8 ft.
AGZ
026-070
3.5 ft.
(1.0m)
4 ft.
(1.2m)
6 ft.
(1.8m)
075-130
4.5 ft.
(1.4m)
(1.8m)
(2.4m)
0
0
IMM AGZ-8 AGZ 026B through 130B 7

Case 2, Two Units Side By Side

Two or more units sited side by side are common. If spaced closer than 12 feet (3.7 meters) or 8 feet (2.5meters) depending on size, it is necessary to adjust the performance of each unit; circuits adjoining each other are affected. NOTE: This case applies only to two units side by side. See Case 3 for three or more parallel units. If one of the two units also has a wall adjoining it, see Case 1. Add the two adjustment factors together and apply to the unit located between the wall and the other unit.
Mounting units end to end will not necessitate adjusting performance. Depending on the actual arrangement, sufficient space must be left between the units for access to the control panel door opening and/or evaporator tube removal. See “Clearance” section of this guide for requirements for specific units.
Figure 7, Two Units Side by Side
Figure 8, Adjustment Factor
3.0
2.0
1.0
0
AGZ 075-130
AGZ 026-070
9
(2.7)
6.5
(2.0)
10
(3.0)
7
(2.1)
11
(3.3)
7.5
(2.2)
12
(3.6)
8
(2.4)
AGZ 075-130 AGZ 026-070
6.0
4.0
2.0
0
9
(2.7)
6.5
(2.0)
10
(3.0)
7
(2.1)
11
(3.3)
7.5
(2.2)
12
(3.6)
8
(2.4)
8 AGZ 026B through 130B IMM AGZ-8

Case 3, Three or More Units Side By Side

When three or more units are side by side, the outside chillers (1 and 3 in this case) are influenced by the middle unit only on their inside circuits. Their adjustment factors will be the same as Case 2. All inside units (only number 2 in this case) are influenced on both sides and must be adjusted by the factors shown below.
Figure 9, Three or More Units
AGZ 075-130
AGZ 026-070
Chiller 1 Chiller 2 Chiller 3
Figure 10, Adjustment Factor
4.0
3.0
2.0
1.0
0
15
(4.6)
11
(3.3)
16
(4.9)
12
(3.7)
17
(5.2)
13
(4.0)
18
(5.5)
14
(4.3)
AGZ 075-130 AGZ 026-070
8.0
6.0
4.0
2.0
0
15
(4.6)
11
(3.3)
16
(4.9)
12
(3.7)
17
(5.2)
13
(4.0)
18
(5.5)
14
(4.3)
IMM AGZ-8 AGZ 026B through 130B 9

Case 4, Open Screening Walls

Decorative screening walls are often used to help conceal a unit either on grade or on a rooftop. These walls should be designed such that the combination of their open area and distance from the unit do not require performance adjustment. It is assumed that the wall height is equal to or less than the unit height when mounted on its base support. This is usually satisfactory for concealment. If the wall height is greater than the unit height, see Case 5, Pit Installation.
The distance from the ends of the unit to the end walls should be sufficient for service, opening control panel doors, and pulling evaporator tubes, as applicable.
If each side wall is a different distance from the unit, the distances can be averaged providing either wall is not less than 8 feet (2.4 meters) from the unit. For example, do not average 4 feet and 20 feet to equal 12 feet.
Figure 11, Open Screening Walls
Figure 12, Wall Free Area vs Distance
AGZ
026-070
4
(1.2)
3.5
(1.0)
3.0
(0.9)
2.5
(0.7)
AGZ
075-130
6
(1.8)
5
(2.0)
4
(1.2)
3
(0.9)
01020304050
10 AGZ 026B through 130B IMM AGZ-8
Case 5, Pit/Solid Wall Installation
A
A
A
A
A
A
A
Pit installations can cause operating problems and great care should be exercised if they are to be used on an installation. Recirculation and restriction can both occur. A solid wall surrounding a unit is substantially the same as a pit and the data presented here should be used.
Steel grating is sometimes used to cover a pit to prevent accidental falls or trips into the pit. The grating material and installation design must be strong enough to prevent such accidents, yet provide abundant open area or serious recirculation problems will occur. Have any pit installation reviewed by McQuay application engineers prior to installation to make sure it has sufficient air-flow characteristics. The installation design engineer must approve the work to avoid the risk of accident.
Figure 13, Pit Installation
Figure 14, Adjustment Factor
D=4
(1.4)
D=6
(1.8)
D=5 (2.0)
D=8 (2.4)
075-130
GZ
026-070
AGZ
075-130
GZ
D=10
(3.1)
GZ
026-070
D=7 (2.1)
D=4 (1.4)
D=6 (1.8)
D=5 (2.0)
D=8 (2.4)
GZ
075-130
D=10
(3.1)
GZ
026-070
D=7 (2.1)
GZ
026-070
GZ
075-130
IMM AGZ-8 AGZ 026B through 130B 11

Sound Isolation

The low sound level of the AGZ chiller is 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 transmission through electrical conduit. Spring isolators are effective in reducing the low amplitude sound generated by scroll compressors and for unit isolation in sound sensitive areas.

Vibration Isolators

Vibration isolators are recommended for all roof-mounted installations or wherever vibration transmission is a consideration.
Table 2 lists isolator loads for all unit sizes.
RP-4, Neoprene-in-Shear Dimensions
CP-2, Spring Isolator Dimensions
Figure 15 shows isolator locations. See Dimensional Data starting on page 41 for detailed mounting hole locations.
Isolators are also recommended for slab installations, primarily to keep the unit base from resting its entire length directly on the slab.

Isolator Installation

The unit should be initially installed on shims or blocks at the listed free height. When all piping, wiring, flushing, charging, etc. is completed, adjust the springs upward to load them and to provide clearance to remove the shims or blocks.
Installation of spring isolators requires flexible piping connections and at least three feet of conduit flex tie-ins. Piping and conduit must be supported independently of the unit.
Bolting: if the chiller base is to be bolted to the isolators, it is recommended that the short threaded studs usually found on isolators be replaced with eight-inch threaded rod that can extend through the holes on the top of the base and then be bolted. Washers will be required.
Figure 15, Isolator Locations
4 or 6 FAN U N IT 8 FAN UN IT
34
45
6
CONTROL
PANEL
12
12 AGZ 026B through 130B IMM AGZ-8
CONTROL
PANEL
12
3
Table 2, AGZ-BS/BH, Packaged, Isolator Loads At Each Mounting Location
(With Aluminum Fins)
Unit
Qty.
Size
Fan
026B 030B 035B 040B 045B 050B 055B 060B 065B 070B 075B 085B 090B 100B 110B 120B 130B
4 1281 580 941 426 1020 462 748 339 - - - - 3990 1807 72 32 4 1297 588 952 431 1032 467 759 344 - - - - 4040 1830 72 32 4 1283 581 942 427 1069 484 786 356 - - - - 4080 1848 72 32 4 1360 616 940 426 1082 490 748 339 - - - - 4130 1871 72 32 4 1377 624 952 431 1148 520 793 359 - - - - 4270 1934 72 32 4 1384 627 1016 460 1153 522 847 384 - - - - 4400 1993 119 54 4 1391 630 1085 492 1159 525 905 410 - - - - 4540 2057 119 54 4 1410 639 1099 498 1175 532 916 415 - - - - 4600 2084 142 65 4 1382 626 1214 550 1205 546 1059 480 - - - - 4860 2202 142 65 4 1419 643 1246 564 1238 561 1087 492 - - - - 4990 2260 217 99 6 1854 840 1411 639 1854 840 1411 639 - - - - 6530 2958 217 99 6 1942 880 1479 670 1856 841 1413 640 - - - - 6690 3031 217 99 6 1975 895 1450 657 1975 895 1450 657 - - - - 6850 3103 217 99 8 1464 663 1341 607 1219 552 1400 634 1282 581 1164 527 7870 3565 289 131 8 1513 685 1358 615 1204 545 1513 685 1358 615 1204 545 8150 3692 289 131 8 1656 750 1486 673 1317 597 1582 717 1420 643 1259 570 8720 3950 289 131 8 1714 776 1508 683 1303 590 1714 776 1508 683 1303 590 9050 4100 289 131
NOTE (1): Additional weight for copper coils is per mounting location.
1 2 3 4 5 6 Total Unit
lb kg lb kg lb kg lb kg lb kg lb kg lb kg lb. kg
Table 3, Isolator Kit Numbers
AGZ
Model
Spring Kit
Part No. R-I-S Kit Part No.
026, 030
035
330349603 330349603 330349605 330349606 330349607 330349609 330349612 330349613 330349614 330349702 330349703 330349704 330349704 330349705 330349706 330349707 330349708 330349709
040, 045
050
055 060 065, 070
075, 085
090
100 110 120,130
(1) Copper
Fin Add
Table 4, Isolator Locations
AGZ-B, Chillers
Operating Weight. Neoprene-In-Shear Mountings Spring-Flex Mountings
Unit
Size
026B 030B 035B 040B 045B 050B 055B 060B 065B 070B 075B 085B 090B 100B 110B 120B 130B
lbs kg 3990 1807 4040 1830 4080 1848 4130 1871 4270 1934 4400 1993 4540 2057 4600 2084 4860 2202 4990 2260 6530 2958 6690 3031 6850 3103 7870 3565 8150 3692 8720 3950 9050 4100
1 2 3 4 5 6 1 2 3 4 5 6
Black Gray Gray Gray - - Orange Purple Purple Red - ­Black Gray Gray Gray - - Orange Purple Purple Red - ­Black Gray Gray Gray - - Orange Purple Purple Red - ­Black Gray Black Gray - - Orange Purple Purple Red - ­Black Gray Black Gray - - Orange Purple Purple Red - ­Black Gray Black Gray - - Orange Purple Purple Red - ­Black Black Black Gray - - Orange Purple Purple Purple - ­Black Black Black Gray - - Orange Purple Orange Purple - ­Black Black Black Black - - Orange Orange Orange Purple - ­Black Black Black Black - - Orange Orange Orange Purple - -
Red Black Red Black - - Gray Orange Gray Orange - ­Red Black Red Black - - Gray Orange Gray Orange - ­Red Black Red Black - - Gray Orange Gray Orange - -
Black Black Black Black Black Black Orange Orange Orange Orange Orange Orange
Red Black Black Red Black Black Green Orange Orange Green Orange Orange Red Red Black Red Red Black Green Green Orange Green Green Orange Red Red Black Red Red Black Green Green Orange Green Green Orange
NOTE: Neoprene-in-shear isolators: Gray=RP-3 Gray, Black=RP-4 Black, Red=RP-4 Red.
IMM AGZ-8 AGZ 026B through 130B 13
Table 5, AGZ BM/BB, Isolator Loads At Each Mounting Location (With
Aluminum Fins)
AGZ-
BM/BB
Model
AGZ 026
AGZ 030
AGZ 035
AGZ 040
AGZ 045
AGZ 050
AGZ 055
AGZ 060
AGZ 065
AGZ 070
NOTE (1): Additional weight for copper coils is per mounting location.
Shipping
lbs 3550 3600 1227 901 849 623 3600 72
kg 1608 1631 556 408 385 282 1631 32
lbs 3550 3600 1227 901 849 623 3600 72
kg 1608 1631 556 408 385 282 1631 32
lbs 3550 3600 1227 901 849 623 3600 72
kg 1608 1631 556 408 385 282 1631 32
lbs 3550 3610 1261 872 873 604 3610 72
kg 1608 1635 571 395 395 274 1635 32
lbs 3590 3650 1275 881 883 611 3650 72
kg 1626 1653 578 399 400 277 1653 32
lbs 3730 3800 1295 951 896 658 3800 119
kg 1690 1721 587 431 406 298 1721 54
lbs 3780 3850 1303 1016 860 671 3850 119
kg 1712 1744 590 460 390 304 1744 54
lbs 3820 4040 1367 1066 903 704 4040 142
kg 1730 1830 619 483 409 319 1830 65
lbs 3970 4070 1305 1146 862 757 4070 142
kg 1798 1844 591 519 390 343 1844 65
lbs 4080 4180 1278 1192 885 825 4180 217
kg 1848 1894 579 540 401 374 1894 99
Wt
Operating.
Wt
Loc. 1 Loc. 2 Loc. 3 Loc. 4 Total
(1) Add’l for
Copper Fins
Table 6, Isolator Loads At Each Mounting Location (With Aluminum Fins)
AGZ-
BM/BB
Model
AGZ 075
AGZ 085
AGZ 090
AGZ 100
AGZ 110
AGZ 120
AGZ 130
Shipping
lbs 5510 5630 1649 1166 1649 1166 - - 5630 217
kg 2496 2550 747 528 747 528 - - 2550 99
lbs 5670 5790 1734 1227 1657 1172 - - 5790 217
kg 2569 2623 786 556 751 531 - - 2623 99
lbs 5830 5950 1770 1205 1770 1205 - - 5950 217
kg 2641 2695 802 546 802 546 - - 2695 99
lbs 6820 6970 1323 1188 1053 1265 1135 1006 6970 289
kg 3089 3157 599 538 477 573 514 456 3157 131
lbs 7080 7230 1396 1205 1014 1396 1205 1014 7230 289
kg 3207 3275 632 546 459 632 546 459 3275 131
lbs 7360 7480 1477 1275 1073 1411 1218 1026 7480 289
kg 3334 3388 669 578 486 639 552 465 3388 131
lbs 7640 7760 1555 1293 1032 1555 1293 1032 7760 289
kg 3461 3515 704 586 467 704 586 467 3515 131
NOTE (1): Additional weight for copper coils is per mounting location.
Wt.
Operating
Wt.
Loc 1 Loc 2 Loc 3 Loc 4 Loc 5 Loc 6 TOTAL
(1) Add’l for
Copper Fins
Table 7, Isolator Kit Part Numbers
AGZ-BM Model 026 - 035 040 - 060 065 070 075 - 090 100, 110 120, 130
Spring Kit Part No.
R-I-S Kit Part No.
330349601 330349602 330349603 330349604 330349608 330349610 330349611 330349701 330349701 330349703 330349703 330349706 330349707 330349708
14 AGZ 026B through 130B IMM AGZ-8
Table 8,AGZ BM/BB, Remote Evaporator, Isolator Locations
ACZ-BS, AGZ-BM Less Evaporator Units
AGZ-
BM/BB
Model
026 030 035 040 045 050 055 060 065 070 075 085 090 100 110 120 130
NOTE (1): Position #4 is a CP-1, single spring isolator for ACZ 030 to 065 and AGZ 026 to 060. All others are CP-2, two
Operating
Weight
lbs kg 1 2 3 4 5 6 1 2 3 4 (1) 5 6
3600 1631 Black Gray Gray Green - - Orange Purple Red Orange 3600 1631 Black Gray Gray Green - - Orange Purple Red Orange - ­3600 1631 Black Gray Gray Green - - Orange Purple Red Orange - ­3610 1635 Black Gray Gray Green - - Orange Purple Purple Orange - ­3650 1653 Black Gray Gray Green - - Orange Purple Purple Orange - ­3800 1721 Black Gray Gray Green - - Orange Purple Purple Orange - ­3850 1744 Black Gray Gray Green - - Orange Purple Purple Orange - ­4040 1830 Black Gray Gray Green - - Orange Purple Purple Orange - ­4070 1844 Black Black Gray Gray - - Orange Purple Purple Red - ­4180 1894 Black Black Gray Gray - - Orange Orange Purple Red - ­5630 2550 Red Black Red Black - - Green Orange Green Orange - ­5790 2623 Red Black Red Black - - Green Orange Green Orange - ­5950 2695 Red Black Red Black - - Green Orange Green Orange - ­6970 3157 Black Black Black Black Black Black Orange Orange Purple Orange Orange Purple 7230 3275 Black Black Black Black Black Black Orange Orange Purple Orange Orange Purple 7480 3388 Red Black Black Red Black Black Green Orange Purple Green Orange Purple 7760 3515 Red Black Black Red Black Black Green Orange Purple Green Orange Purple
spring.
Neoprene-In-Shear Mountings Spring-Flex Mountings

Ambient Air Temperature Limitations

Standard/High Ambient Panels

Models AGZ-B (26 to 130 tons, two circuit) have electrical data and subsequent field wiring requirements that are tailored to individual applications.
There are many installations where the expected summer ambient air temperatures will be at 105°F (40.1°C) or less, resulting in smaller unit electrical requirements compared to operation at 106°F (41.1) and above. In these lower temperature cases, there can be considerable installation cost savings by using smaller and more appropriate electrical service.
Therefore, the AGZ electrical data is divided into two classifications based on the design ambient temperature where the unit will operate. Standard Ambient unit electrical data (BS and BM models) is for operation in ambient temperatures of 105°F (40.1°C) or less. Units with the High Ambient designation (BH and BB models) are for use above 105°F (40.1°C) to 125°F (51.7°C).
The AGZ-B units for high ambient operation require the addition of the High Ambient Control Panel Option, which includes the addition of a small fan with a filter in the air intake to cool the control panel, and a unit nameplate that lists the larger electrical requirements.
All units with the optional VFD low ambient fan control automatically include the High Ambient Control Panel Option. Operation of the VFD generates a quantity of panel heat best removed by use of a control panel fan.
IMM AGZ-8 AGZ 026B through 130B 15
Winter Operation Temperatures
0°F to 34°F 35°F and Above
Fan Control Optional VFD (1) Standard FanTrol (2) Design Ambient Air Temperature
Electrical Data (3)
105°F >106°F 105°F >106°F
Standard
Ambient
High
Ambient
Standard Ambient
High
Ambient
Panel Fan Required (4) Yes Yes No Yes Model Designator (5)
Packaged BS BH BS BH Remote Evaporator BM BB BM BB
NOTES
1. VFD is variable speed, fan control through the MicroTech II controller.
2. FanTrol is fan cycling off discharge pressure.
3. Standard Ambient electrical data begins on page
4. The VFD option automatically includes the factory-installed panel fan and filter set
5. The designator is the last two characters in the model number, i.e. AGZ 100BS.
41, High Ambient data begins on page 51.

Panel Ratings

Vo ltage
208-230
240
380-460
575
Standard
Standard Options
Panel
Optional
VFD
High Short Circuit
Panel (kA)
High Interrupt Panel w/
Disconnect Swt. (kA)
35 5 120 120 35 5 100 100 35 5 65 65
5 5 25 25

Water Flow Limitations, Constant Flow

The evaporator flow rates and pressure drops shown on page 25 are for full load design purposes. The maximum flow rate and pressure drop are based on a 6-degree temperature drop. Avoid higher flow rates with resulting lower temperature drops to prevent potential control problems resulting from very small control bands and limited start up/shut off temperature changes.
The minimum flow and pressure drop is based on a full load evaporator temperature drop of 16-degrees.
Evaporator flow rates below the minimum values can result in laminar flow causing freeze-up problems, scaling and poor control. Flow rates above the maximum values will result in unacceptable pressure drops and can cause excessive erosion, potentially leading to failure.

Water Flow Limitations, Variable Flow

The full load, minimum flow limitation for constant flow is not to be confused with the part load minimum flow rate that must be maintained for chillers operating in primary variable flow pumping systems. As chiller capacity drops, the flow rate for this pumping system will reduce proportionally. See the following table for the part load minimum flo w rates.
Other design practices for variable flow systems requiring a range of evaporator flow rates can be found below.
These minimum flow rates assume that flow will be reduced proportionally to the cooling load.
16 AGZ 026B through 130B IMM AGZ-8
Table 9, Minimum Part Load Flow Rates
AGZ Model 034 026 030 035 040 045 050 055 060
Minimum Part
Load Flow (GPM)
AGZ Model 065 070 075 085 090 100 110 120 130
Minimum Part
Load Flow (GPM)
33 26 29 32 37 41 45 50 55
59 63 71 119 128 146 161 180 194

Variable Speed Pumping

Variable water flow involves changing the water flow through the evaporator as the load changes. McQuay chillers are designed for this duty provided that the rate of change in water flow is slow and the minimum and maximum flow rates for the vessel are not exceeded.
The recommended maximum change in water flow is 10 percent of the change per minute.
The water flow through the vessel must remain above the values listed on
Table 9. If
flow drops below the minimum allowable, large reductions in heat transfer can occur.

Drain Valves at Start-up

Model sizes AGZ 075 and larger have shell-and-tube evaporators. They are drained of water in the factory and shipped with evaporator drain plugs removed and stored in the control panel or with an open ball valve in the drain holes. The drain is located on the bottom of the vessel. Be sure to replace plugs or close the valves prior to filling the vessel with fluid.

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. The following issues must be considered when designing and installing water piping:
1. Vibration eliminators to reduce vibration and noise transmission to the building.
2. Shutoff valves are required to isolate the unit from the piping during unit servicing.
3. Manual or automatic air vent valves at the high points of the system. Drains must
be installed at the lowest points in the system.
4. Adequate water pressure must be maintained (expansion tank or regulating valve).
5. Temperature and pressure indicators located at the unit are required to aid in unit
servicing.
6. A strainer or other means of removing foreign matter from the water before it enters
the pump must cavitation at the pump inlet (consult pump manufacturer for recommendations). The use of a strainer will prolong pump life and keep system performance up.
7. Flush the system water piping thoroughly before making connections to the unit
evaporator. Be sure to install a strainer (40-mesh for models AGZ 010 through 070 and 20-mesh for AGZ 075 through 130) in the return water line before the inlet to the chiller. Design the water piping so the chilled water circulating pump discharges into the evaporator inlet.
8. The unit’s evaporator has a thermostat and heater to prevent freeze-up down to -
20°F (-29°C). The heating cable can be wired to a separate 115V supply circuit. As shipped from the factory, the heating cable is wired to the control circuit. All water piping to the unit must also be protected to prevent freezing.
be installed. Place the strainer far enough upstream to prevent
IMM AGZ-8 AGZ 026B through 130B 17
CAUTION
If separate disconnect is used for the 115V supply to the evaporator heating
cable, mark the disconnect clearly to ensure the disconnect is not accidentally
shut off during cold seasons causing a possible damaging evaporator freeze-up.
9. If the unit is used as a replacement chiller, flush the system thoroughly before unit
installation. Regular water analysis and chemical water treatment for the evaporator loop is recommended immediately at equipment start-up.
10. The total water volume in the system should be sufficient to prevent frequent “on-
off” cycling. Turnover rate should not be less than 4 minutes for normal variable cooling loads.
11. 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. When Glycol or Ice are selected as Unit Mode, the MicroTech II will automatically reset the available range for the Leaving Water Temperature, Freezestat and Evaporator Pressure settings.
12. Reset the freezestat setting to 6 degrees F (3.3 degrees C) below the leaving chilled
water setpoint temperature. See the section titled “Glycol Solutions” for additional information concerning glycol.
13. Perform a preliminary leak check before insulating the piping and filling the
system.
14. Piping insulation should include a vapor barrier to prevent condensation and
possible damage to the building structure.
Figure 16, AGZ 075 – AGZ 130, Typical Field Evaporator Water Piping
THERMOWELL
T
INLET
T
18 AGZ 026B through 130B IMM AGZ-8
Figure 17, AGZ 026 - AGZ 070, Typical Field Evaporator Water Piping
Air
T
Inlet
Outlet
T
Thermowell
Vent
P
Drain
Vibration
Eliminators
40-Mesh Strainer
Isolation
Valves
Flow
Switch
NOTE: Outdoor piping must be protected if freezing temperatures are a possibility.

Flow Switch

Mount a water flow switch in the leaving water line to shut down the unit when water flow is interrupted. A flow switch is an equipment protection control and should never be used to cycle a unit.
A “paddle” type flow switch is available from McQuay (part number 017503300). Certain flow rates are required to open the switch and are listed in Wire from switch terminals Y and R to the unit control panel terminals shown on the field wiring diagram (page
Installation should be as shown in
70). Figure 18. Connect the normally open contacts of
the flow switch in the unit control center at terminals 44 and 61. 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. Manufacturer’s instructions included with the switch should be followed.
Table 10 on page 19.
NOTE: Differential pressure switches are not recommended for outdoor installation. They can freeze and not indicate a no-flow condition.
Table 10, Flow Switch Minimum/Maximum Flow Rates
(NOTE !)
Min.
Adjst.
Max.
Adjst.
Flow
Flow Lpm 0.8 1.1 2.2 2.8 4.3 11.4 22.9 35.9 38.6 Flow
Flow Lpm 2.8 4.1 6.1 7.3 11.4 27.7 53.4 81.8 90.8
NOTES:
1. A segmented 3-inch paddle (1, 2, and 3 inches) is furnished mounted, plus a 6-inch paddle loose.
2. Flow rates for a 2-inch paddle trimmed to fit the pipe.
3. Flow rates for a 3-inch paddle trimmed to fit the pipe.
4. Flow rates for a 3-inch paddle.
5. Flow rates for a 6-inch paddle
inch 1 1/4 1 1/2 2 2 1/2 3 4 5 6 8 Pipe Size mm 32 (2) 38 (2) 51 63 (3) 76 102 (4) 127 (4) 153 (4) 204 (5)
gpm 5.8 7.5 13.7 18.0 27.5 65.0 125.0 190.0 205.0 Lpm 1.3 1.7 3.1 4.1 6.2 14.8 28.4 43.2 46.6 gpm 3.7 5.0 9.5 12.5 19.0 50.0 101.0 158.0 170.0
No
gpm 13.3 19.2 29.0 34.5 53.0 128.0 245.0 375.0 415.0 Lpm 3.0 4.4 6.6 7.8 12.0 29.1 55.6 85.2 94.3 gpm 12.5 18.0 27.0 32.0 50.0 122.0 235.0 360.0 400.0
No
IMM AGZ-8 AGZ 026B through 130B 19
Figure 18, Flow Switch Installation
Flow direction marked on switch
1" (25mm) NPT flow switch
Tee
connection

Water Connections

Bring water piping to the evaporator through the side between the vertical supports. Provide taps for the connection of pressure gauges and thermometers in the inlet and outlet lines. Check the inlet and outlet labels on the unit against the certified drawings supplied on the job and be sure the water piping is hooked up correctly. Contact the McQuay sales office if any discrepancies exist.

System Water Volume Considerations

All chilled water systems need adequate time to recognize a load change, respond to that load change and stabilize, without undesirable short cycling of the compressors or loss of control. In air conditioning systems, the potential for short cycling usually exists when the building load falls below the minimum chiller plant capacity or on close-coupled systems with very small water volumes.
Some of the things the designer should consider when looking at water volume are the minimum cooling load, the minimum chiller plant capacity during the low load period and the desired cycle time for the compressors.
Assuming that there are no sudden load changes and that the chiller plant has reasonable turndown, a rule of thumb of “gallons of water volume equal to two to three times the chilled water gpm flow rate” is often used.
A properly designed storage tank should be added if the system components do not provide sufficient water volume.

Variable Speed Pumping

Variable water flow involves reducing the water flow through the evaporator as the load decreases. McQuay chillers are designed for this duty provided that the rate of change in water flow is not greater than 10 percent of the change per minute.
The water flow through the vessel must remain above the values shown on
17. If flow drops below the minimum allowable, large reductions in heat transfer
page can occur.
Table 9 on

Glycol Solutions

The use of a glycol/water mixture in the evaporator to prevent freezing will reduce system capacity and efficiency, as well as increase pressure drop. The system capacity, required glycol solution flow rate, and pressure drop with glycol may be calculated using the following formulas and tables.
1. Capacity – Multiply the capacity based on water by the Capacity correction factor
Table 11 through Table 14.
from
2. Flow – Multiply the water evaporator flow by the Flow correction factor from
Table 11 through Table 14 to determine the increased evaporator flow due to glycol.
20 AGZ 026B through 130B IMM AGZ-8
If the flow is unknown, it can be calculated from the following equation:
T
)(24
×
=
CapacitykW
Delta
18.4
×
For Metric Applications
(gpm) Flow Glycol FactorCorrectionFlow
– Use the following equation for metric applications:
=
(l/s) Flow Glycol
3. Pressure drop -- Multiply the water pressure drop from page
correction factor from
Table 11 through Table 14. High concentrations of
glycolCapacityTons
TDelta
×
×
FactorCorrectionFlow
)
25 by Pressure Drop
propylene glycol at low temperatures may cause unacceptably high pressure drops.
4. Power -- Multiply the water system power by Power correction factor from
11 through
Table 14.
Table
Test coolant with a clean, accurate glycol solution hydrometer (similar to that found in service stations) to determine the freezing point. Obtain percent glycol from the freezing point table below. It is recommended that a minimum of 25% solution by weight be used for protection against corrosion or that additional compatible inhibitors be added. Concentrations above 35 percent do not provide any additional burst protection and should be carefully considered before using.
CAUTION
Do not use an automotive grade antifreeze. Industrial grade glycols must be
used. Automotive antifreeze contains inhibitors which will cause plating on the
copper tubes within the chiller evaporator. The type and handling of glycol used
must be consistent with local codes.
Table 11, Ethylene Glycol Factors for Models AGZ 026B to 070B
% E.G.
10 20 30 40 50
Freeze Point
o
F
26 -3.3 0.998 0.998 1.036 1.097 18 -7.8 0.993 0.997 1.060 1.226
7 -13.9 0.987 0.995 1.092 1.369
-7 -21.7 0.980 0.992 1.132 1.557
-28 -33.3 0.973 0.991 1.182 1.791
o
C
Capacity Power Flow PD
Table 12, Propylene Glycol Factors for Models AGZ 026B to 070B
% P.G.
10 20 30 40 50
Freeze Point
o
F
26 -3.3 0.995 0.997 1.016 1.100 19 -7.2 0.987 0.995 1.032 1.211
9 -12.8 0.978 0.992 1.057 1.380
-5 -20.6 0.964 0.987 1.092 1.703
-27 -32.8 0.952 0.983 1.140 2.251
o
C
Capacity Power Flow PD
IMM AGZ-8 AGZ 026B through 130B 21
Table 13, Ethylene Glycol Factors for Models AGZ 075B to 130B
% E.G.
10 20 30 40 50
Freeze Point
o
F
26 -3.3 0.994 0.998 1.038 1.101 18 -7.8 0.982 0.995 1.063 1.224
7 -13.9 0.970 0.992 1.095 1.358
-7 -21.7 0.955 0.987 1.134 1.536
-28 -33.3 0.939 0.983 1.184 1.755
o
C
Capacity Power Flow PD
Table 14, Propylene Glycol Factors for Models AGZ 075B to 130B
% P.G.
10 20 30 40 50
Freeze Point
o
F
26 -3.3 0.988 0.996 1.019 1.097 19 -7.2 0.972 0.992 1.035 1.201
9 -12.8 0.951 0.987 1.059 1.351
-5 -20.6 0.926 0.979 1.095 1.598
-27 -32.8 0.906 0.974 1.142 2.039
o
C
Capacity Power Flow PD

Pumpdown

The pumpdown capacity of AGZ units is given in the Physical Data Tables. Care should be exercised to include all equipment and lines when calculating the system charge relative to pumpdown capacity on remote evaporator units. The AGZ remote evaporators have an insignificant operating charge.

Altitude Correction Factors

Performance tables are based at sea level. Elevations other than sea level affect the performance of the unit. The decreased air density will reduce condenser capacity consequently reducing the unit's performance. For performance at elevations other than sea level, refer to

Evaporator Temperature Drop Factors

Performance tables are based on a 10-degree F (5-degree C) temperature drop through the evaporator. Adjustment factors for applications with temperature ranges from 6 to 16-degree F (3.3 to 8.9-degree C) are in
Temperature drops outside this 6 to 16-degree F (3.3 to 8.9-degree C) range can affect the control system's capability to maintain acceptable control and are not recommended.
The maximum water temperature that can be circulated through the evaporator in a non-operating mode is 100°F (37.8°C).

Fouling Factor

Performance tables are based on water with a fouling factor of
As fouling is increased, performance decreases. For performance at other than 0.0001 (0.0176) fouling factor, refer to
Table 15 and Table 16.
Foreign matter in the chilled water system will adversely affect the heat transfer capability of the evaporator and could increase the pressure drop and reduce the water flow. Maintain proper water treatment to provide optimum unit operation.
22
)/0176.0(/0001.0
kWCmorBTUFhrft °×°×× per ARI 550/590-98.
22 AGZ 026B through 130B IMM AGZ-8
Table 15, Capacity and Power Derates, Models AGZ 026B to 070B
Fouling Factor
Altitude
Sea
Level
2000 feet
610 meters
4000 feet
1220 meters
6000 feet
1830 meters
Chilled Water
Delta T
°F °C Cap. Power Cap. Power Cap. Power Cap. Power
6 3.3 0.978 0.993 0.975 0.991 0.963 0.987 0.940 0.980
8 4.4 0.989 0.996 0.986 0.994 0.973 0.990 0.950 0.983 10 5.6 1.000 1.000 0.996 0.999 0.984 0.994 0.961 0.987 12 6.7 1.009 1.003 1.005 1.001 0.993 0.997 0.969 0.990 14 7.7 1.018 1.004 1.014 1.003 1.002 0.999 0.978 0.991 16 8.9 1.025 1.007 1.021 1.006 1.009 1.001 0.985 0.994
6 3.3 0.977 1.001 0.973 1.000 0.961 0.996 0.938 0.989
8 4.4 0.987 1.006 0.984 1.004 0.971 1.000 0.948 0.993 10 5.6 0.998 1.009 0.995 1.007 0.982 1.003 0.959 0.996 12 6.7 1.007 1.011 1.004 1.010 0.991 1.006 0.967 0.998 14 7.7 1.014 1.014 1.011 1.013 0.998 1.009 0.974 1.001 16 8.9 1.022 1.016 1.018 1.014 1.005 1.010 0.981 1.003
6 3.3 0.973 1.011 0.970 1.010 0.957 1.006 0.935 0.998
8 4.4 0.984 1.014 0.980 1.013 0.968 1.009 0.945 1.001 10 5.6 0.995 1.019 0.991 1.017 0.979 1.013 0.955 1.005 12 6.7 1.004 1.021 1.000 1.020 0.987 1.016 0.964 1.008 14 7.7 1.011 1.024 1.007 1.023 0.994 1.018 0.971 1.011 16 8.9 1.018 1.027 1.014 1.026 1.002 1.021 0.978 1.014
6 3.3 0.969 1.021 0.966 1.020 0.954 1.016 0.931 1.008
8 4.4 0.980 1.026 0.977 1.024 0.964 1.020 0.942 1.013 10 5.6 0.989 1.029 0.986 1.027 0.973 1.023 0.950 1.015 12 6.7 0.998 1.033 0.995 1.031 0.982 1.027 0.959 1.020 14 7.7 1.007 1.036 1.004 1.034 0.991 1.030 0.967 1.022 16 8.9 1.014 1.037 1.011 1.036 0.998 1.031 0.974 1.024
0.0001 (0.0176) 0.00025 (0.044) 0.00075 (0.132) 0.00175 (0.308)
Table 16, Capacity and Power Derates, Models AGZ 075B to 130B
Fouling Factor
Altitude
Sea
Level
2000 feet
610 meters
4000 feet
1220 meters
6000 feet
1830 meters
Chilled Water
Delta T
°F °C Cap. Power Cap. Power Cap. Power Cap. Power
6 3.3 0.990 0.997 0.976 0.994 0.937 0.983 0.868 0.964
8 4.4 0.994 0.998 0.981 0.995 0.942 0.984 0.872 0.965 10 5.6 1.000 1.000 0.987 0.996 0.947 0.986 0.877 0.967 12 6.7 1.005 1.001 0.991 0.997 0.951 0.986 0.881 0.968 14 7.7 1.009 1.002 0.995 0.998 0.955 0.987 0.884 0.968 16 8.9 1.013 1.004 1.000 1.000 0.960 0.989 0.889 0.970
6 3.3 0.987 1.005 0.974 1.002 0.934 0.991 0.865 0.972
8 4.4 0.992 1.006 0.979 1.003 0.940 0.992 0.870 0.973 10 5.6 0.997 1.008 0.984 1.004 0.944 0.994 0.875 0.975 12 6.7 1.002 1.009 0.989 1.005 0.949 0.994 0.879 0.975 14 7.7 1.007 1.011 0.993 1.007 0.953 0.996 0.883 0.977 16 8.9 1.011 1.012 0.998 1.008 0.958 0.997 0.887 0.978
6 3.3 0.985 1.014 0.972 1.010 0.933 0.999 0.864 0.980
8 4.4 0.991 1.015 0.977 1.012 0.938 1.001 0.869 0.981 10 5.6 0.995 1.016 0.982 1.013 0.943 1.002 0.873 0.982 12 6.7 1.000 1.018 0.987 1.014 0.947 1.003 0.877 0.984 14 6.8 1.005 1.019 0.991 1.015 0.951 1.004 0.881 0.985 16 8.9 1.009 1.021 0.995 1.017 0.955 1.006 0.884 0.987
6 3.3 0.982 1.023 0.969 1.020 0.930 1.009 0.861 0.989
8 4.4 0.988 1.025 0.975 1.022 0.935 1.010 0.866 0.991 10 5.6 0.992 1.026 0.979 1.022 0.940 1.011 0.870 0.992 12 6.7 0.997 1.028 0.984 1.024 0.944 1.013 0.875 0.994 14 7.7 1.002 1.029 0.989 1.025 0.949 1.014 0.879 0.995 16 8.9 1.006 1.031 0.992 1.027 0.952 1.016 0.882 0.996
0.0001 (0.0176) 0.00025 (0.044) 0.00075 (0.132) 0.00175 (0.308)
IMM AGZ-8 AGZ 026B through 130B 23

Evaporator Freeze Protection

Evaporator freeze-up can be a concern in the application of air-cooled water chillers. To protect against freeze-up, insulation and an electric heater cable are furnished with the unit. This protects the evaporator down to -20°F (-29°C) ambient air temperature. Although the evaporator is equipped with freeze protection, it does not protect water piping external to the unit or the evaporator itself if there is a power failure or heater cable burnout. Consider the following recommendations for additional protection.
1. If the unit will not be operated during the winter, drain evaporator and chilled water piping
and flush with glycol. Drain and vent connections are provided on the evaporator to ease draining.
2. Add a glycol solution to the chilled water system to provide freeze protection. Freeze
point should be approximately ten degrees below minimum design ambient temperature.
3. The addition of thermostatically controlled heat and insulation to exposed piping.
4. Continuous circulation of water through the chilled water piping and evaporator.
The evaporator heater cable is factory wired to the 115-volt circuit in the control box. This power should be supplied from a separate source, but it can be supplied from the control circuit. Operation of the heater cable is automatic through the ambient sensing thermostat that energizes the evaporator heater cable for protection against freeze-up. Unless the evaporator is drained in the winter, the disconnect switch to the evaporator heater must not be open.

Operating/Standby Limits

Maximum standby ambient air temperature, 130°F (55°C) Maximum operating ambient air temperature
Standard Ambient Unit, 105°F (40.6°C) and below, Models BS and BM
High Ambient Unit, above 105°F (40.6°C) to 125°F 51.7°C), Models BH and BB Minimum operating ambient temperature (standard), 35°F (2°C) Minimum operating temperature (with optional low-ambient control), 0°F (-18°C) Leaving chilled water temperature, R-22, 40ºF to 60°F (4.4°C to 15.6°C) Leaving chilled water temperature, R-407C, 42°F to 60°F (5.5°C to 15.6°C) Leaving chilled fluid temperatures (with anti-freeze), 20°F to 60°F (-7°C to 16°C) Design chilled water Delta-T range, 6 to 16 degrees F (3.3 to 8.9 degrees C) Part load minimum flow for variable flow systems; varies with unit size, see below Maximum operating inlet fluid temperature, 76°F (24°C) Maximum non-operating inlet fluid temperature, 100°F (38°C) Electric power supply, see page
69

Evaporator Flow and Pressure Drop Water Flow Limitations

The evaporator flow rates and pressure drops shown on page 25 are for full load, constant flow design purposes.
See the page systems requiring a range of evaporator flow rates can be found on page
24 AGZ 026B through 130B IMM AGZ-8
16 for the part load minimum flow rates. Other design practices for variable flow
20.
Figure 19, AGZ 026B – 130B, Evaporator Pressure Drop
040
045
050
055
026-030
065-070
035
075-085-090
120-130
060
100-110
AGZ Unit
Model
026B 030B 035B 040B 045B 050B 055B 060B 065B 070B 075B 085B 090B 100B 110B 120B 130B
NOTE: Minimum and maximum flows provide a Delta-T for each unit size within a 6 - 16°F range for proper control.
Inch-Pound S.I. Inch-Pound S.I. Inch-Pound S.I.
gpm DP ft. lps DP kpa gpm DP ft. lps DP kpa gpm DP ft. lps DP kpa
41 1.6 2.6 4.7 65 3.9 4.1 11.6 109 10.4 6.9 30.9 45 1.9 2.9 5.7 72 4.7 4.6 14.1 121 12.7 7.6 37.8 50 1.9 3.1 5.6 80 4.6 5.0 13.8 133 12.4 8.4 36.9 58 1.9 3.6 5.7 92 4.7 5.8 14.0 154 12.6 9.7 37.5 64 1.8 4.0 5.4 102 4.5 6.4 13.4 170 12.1 10.7 35.9 71 1.8 4.4 5.4 113 4.5 7.1 13.3 188 12.0 11.9 35.7 78 1.8 4.9 5.3 125 4.4 7.9 13.0 209 11.7 13.2 34.8 86 1.7 5.4 5.2 137 4.3 8.6 12.8 228 11.5 14.4 34.2 92 1.6 5.8 4.9 147 4.1 9.3 12.1 246 10.9 15.5 32.5
98 1.9 6.2 5.6 157 4.6 9.9 13.7 262 12.3 16.5 36.8 111 5.6 7.0 16.5 177 12.5 11.2 37.4 295 30.4 18.6 90.7 119 6.3 7.5 18.9 191 14.3 12.1 42.7 318 34.8 20.1 103.6 128 7.2 8.1 21.4 205 16.2 12.9 48.4 342 39.4 21.6 117.3 146 2.6 9.2 7.7 234 6.1 14.8 18.2 390 15.5 24.6 46.2 161 3.1 10.2 9.2 258 7.3 16.3 21.7 430 18.5 27.1 55.1 180 3.5 11.3 10.4 288 8.9 18.1 26.5 479 24.6 30.2 73.4 194 4.1 12.2 12.1 311 10.4 19.6 30.9 518 28.7 32.7 85.6
IMM AGZ-8 AGZ 026B through 130B 25
Minimum Nominal Maximum

Wind Baffles and Hail Guards

CO
G
Protection against negative effects from wind and protection against fin damage from hail can be achieved from two separate options from McQuay. Factory or field installed louvers are available as well as the box-type enclosures described below.
Wind Baffles/Hail Guards are a field installed option that are used to stabilize unit operation in high wind areas and to assist in operation at low ambient temperatures. sketch of a typical panel assembly on an AGZ unit. The actual number of panels and parts will vary by model size, being one set per fan, on each side (see
Table 19 through Table 22 for number of fans. The parts are shown in the table below and referenced by balloon numbers.
Figure 20, Installation Sequence

Rib Attachment (First)

RIB FLANGES ON THE END
MUST POINT TO CENTER OF COIL TO HAVE A FINISHED LOOK. INTERIOR RIB FLANGES
CAN POINT IN ANY DIRECTION.
U
V
T
N
I
E
R
C
T
I
C
A
O
L
L
I
Figure 20 is a

Front Panel Attachment (Second)

PLACE FRONT "A" AND FASTEN TO BOTH SIDES
L
I
C
O
L
A
C
I
T
E
R
V
T
N
I
U
C
B
2
1
A
3
ATTACH ALL RIBS TO
IL VERTICAL CHANNELS.
E
D
PLACE FRONT "B" BY LAPPIN OVER "A" AND REPEAT ATTACHMENT PROCEDURE.
26 AGZ 026B through 130B IMM AGZ-8

Top Panel Attachment (Last)

A
.
O
TTACH TOP "A" AT HORIZONTAL COIL CHANNEL FIRST.
THIS WILL SQUARE THE PANEL.
OVERLAP THE FRONT PANEL FLANGE.
C
O
I
L
C
L
A
I
T
R
E
I
V
T
U
N
B
A
Table 17, Packing List
Description Part Number Bubble Number
Vertical Support Rib 074758501 1
Top Cover 330409401 2
¼ - 20 x ½” Screw (Place in Poly Bag) 046093807
Front Panel 330409501 3
E
D
C
ATTACH LEFT SIDE SECOND.
LAP PANEL "B" OVER PANEL "A" AND REPEAT ATTACHMENT PROCEDURE
Figure 21, Components
Top Panel, Install Last
Overlap the Front panel
T
REAR (AGAINST UNIT)
VERTICAL SUPPORT RIB TOP COVER FRONT PANEL
P
Front Panel, Install Second
Rib, Install First
IMM AGZ-8 AGZ 026B through 130B 27
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