Daikin McQuay AGZ-D 25 Operating instructions

Operating and Maintenance Manual OMM 1087-1
Group: Chiller
Part Number: OMM 1087
Effective: August 2012
Supersedes: May 2012
Air-Cooled Scroll Compressor Chiller
AGZ-D 25 to 190 Tons
50 - 60-Hertz, R-410A
Software Version 251699201

2AGZ 025D through 190D OMM 1087-1
Table of Contents
Introduction........................................3
Operating/Standby Limits............................ 9
Pressure Drop Curves........................9
MicroTechIII Controller .............13
Controller Section Table of Contents......... 13
Security...................................................... 20
Unit Functions..................................20
Definitions................................................. 20
Unit Enable................................................ 21
Unit Mode Selection.................................. 22
Unit States.................................................. 22
Power Up Start Delay................................ 23
Ice Mode Start Delay................................. 23
Unit Status ................................................. 23
Evaporator Pump Control.......................... 24
LWT Target................................................ 25
Unit Capacity Control................................ 26
Unit Capacity Overrides ............................ 27
Circuit Functions..............................29
Definitions................................................. 29
Circuit Control Logic................................. 29
Pumpdown Procedure................................ 31
LowAmbient Starts ................................... 31
Circuit Status ............................................. 31
Compressor Control................................... 31
Condenser Fan Control.............................. 32
EXV Control.............................................. 34
Liquid Line Solenoid Valve....................... 35
Hot Gas Bypass Solenoid Valve ................ 35
Capacity Overrides – Limits of Operation. 35
Alarms...............................................35
Unit Fault Alarms....................................... 35
Unit ProblemAlarms................................. 37
Unit Warning Alarms..................................38
Circuit Fault Alarms...................................38
Circuit Events.............................................40
Circuit Warning Alarms..............................41
Events............................................... 41
Unit Events.................................................42
Circuit Events.............................................42
Clearing Alarms..........................................43
Using the Controller........................ 44
Navigating..................................................45
Menus.........................................................47
Optional Low Ambient Fan VFD .. 60
VFD Interface (HMI).................................61
Recommended Periodic Inspection............65
Optional BAS Interface.................. 65
Startup.............................................. 66
Operation......................................... 68
Unit Maintenance............................ 72
Planned Maintenance Schedule..................73
Service.............................................. 75
R-410A.......................................................75
Refrigerant Charging..................................76
Evaporator..................................................79
AGZ-D Troubleshooting Chart...... 80
Warranty Statement........................ 82
Cover picture: AGZ 190D, 190 nominal tons capacity.
Our facility is ISO Certified
©2012 McQuay International. Illustrations and data cover the McQuay International product at the time of publication and we reserve the right
to make changes in design and c
onstruction at anytime without notice. ™® The following are trademarks or registered trademarks of their
respective companies: BACnet from ASHRAE; LONMARK, LonTalk, LONWORKS, and the LONMARK logo are managed, granted and used by
LONMARK International under
a license granted by Echelon Corporation; Compliant Scroll from Copeland Corporation; ElectroFin from AST
ElectroFin Inc.; Modbus from Schneider Electric; FanTrol, MicroTech III, Open Choices from McQuay International. *Unit Controllers are
LONMARK certified with an optional LONWORKS communication module.

OMM 1087-1 AGZ 025D through 190D 3
Introduction
General Description
Daikin McQuay Air-Cooled Global Water
Chillers are complete, self-contained automatic
refrigerating units. Every unit is completely
assembled, factory wired, charged, and tested
(except remote evaporator option). 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, , 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.
This manual covers units with Software
Version 251699201 which must be used with
firmware version 9.XX.
Installation, information is in IM 1100 (or
current, latest dash number) manual.
Nomenclature
A GZ-XXX DH
Hazard Identification Information
!
DANGER
Dangers indicate a hazardous situation which will result in death or serious injury if not avoided.
!
WARNING
Warnings indicate potentially hazardous situations, which can result in property damage, severe
personal injury, or death if not avoided.
!
CAUTION
Cautions indicate potentially hazardous situations, which can result in personal injury or equipment
damage if not avoided.
Air-Cooled
Global
Scroll Compressor
Design Vintage
Model Size
(Nominal Tons)
Application
H= Packaged Chiller

4AGZ 025D through 190D OMM 1087-1
Ambient Air Temperature
Limitations
Standard/High Ambient Panels
The maximum operating ambient temperature
for standard units is 104°F (40°C). AGZ-D
units for high ambient operation (105°F to
125°F maximum) 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.
All units with the optional variable frequency
drive (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.
Water Flow Limitations
The evaporator flow rates and pressure drops
shown on page 11 are for full load design
purposes in order to maintain proper unit
control. 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.
Variable Speed Pumping
Variable water flow involves changing the
water flow through the evaporator as the load
changes. Daikin 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.
When units are operated with flow rates less
than nominal (see Table 8 on page 11), the
“Evap Delta T” setpoint must be changed
proportionally to match the minimum
operating flow rate. The “Delta T” setting
should be increased by the same percentage as
the flow reduction is from the nominal rating
in order to prevent short cycling. This will
require reevaluation of “Cool LWT”, “Startup
Delta T”, and “Stop Delta T” settings as well
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
temperature 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.

OMM 1087-1 AGZ 025D through 190D 5
Glycol Solutions
The use of a glycol/water mixture in the evaporator to prevent freezing reduces 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 Table 1.
1. Capacity –Multiply the capacity based on water by the Capacity correction factor from Table 2
through Table 5.
2. Flow – Multiply the water evaporator flow by the Flow correction factor from Table 2 through
Table 5 to determine the increased evaporator flow due to glycol.
If the flow is unknown, it can be calculated from the following equation
3. Pressure drop -- Multiply the water pressure drop from page 10 by Pressure Drop correction
factor from Table 2 through Table 5. High concentrations of propylene glycol at low temperatures
can cause unacceptably high pressure drops.
4. Power -- Multiply the water system power by Power correction factor from Table 2 - Table 5.
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 tables 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 % do not provide any additional burst protection and should be carefully
considered before using.
Table 1, Flow/Tons/Delta-T Relationship
Glycol Flow (gpm)
FactorCorrectionFlow
TDelta
glycolCapacityTons × ×)(24
Glycol Flow (l/s) FactorCorrectionFlow
TDelta
CapacitykW ×
−×
18.4
!
WARNING
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 2, Ethylene Glycol Factors for Models AGZ 025D to 130D
% E.G. Freeze Point Capacity Power Flow PD
oF oC
10
26 -3.3 0.998 0.998 1.036 1.097
20 18 -7.8 0.993 0.997 1.060 1.226
30 7 -13.9 0.987 0.995 1.092 1.369
40 -7 -21.7 0.980 0.992 1.132 1.557
50 -28 -33.3 0.973 0.991 1.182 1.791
Table 3, Propylene Glycol Factors for Models AGZ 025D to 130D
% P.G. Freeze Point Capacity Power Flow PD
o
F
o
C
10
26 -3.3 0.995 0.997 1.016 1.100
20 19 -7.2 0.987 0.995 1.032 1.211
30 9 -12.8 0.978 0.992 1.057 1.380
40 -5 -20.6 0.964 0.987 1.092 1.703
50 -27 -32.8 0.952 0.983 1.140 2.251

6AGZ 025D through 190D OMM 1087-1
Table 4, Ethylene Glycol Factors for Models AGZ 140D to 190D
% E.G.
Freeze Point
Capacity Power Flow PD
oF oC
10 26 -3.3 0.994 0.998 1.038 1.101
20
18 -7.8 0.982 0.995 1.063 1.224
30 7 -13.9 0.970 0.992 1.095 1.358
40
-7 -21.7 0.955 0.987 1.134 1.536
50 -28 -33.3 0.939 0.983 1.184 1.755
Table 5, Propylene Glycol Factors for Models AGZ 140D to 190D
% P.G.
Freeze Point
Capacity Power Flow PD
oF oC
10 26 -3.3 0.988 0.996 1.019 1.097
20 19 -7.2 0.972 0.992 1.035 1.201
30 9 -12.8 0.951 0.987 1.059 1.351
40
-5 -20.6 0.926 0.979 1.095 1.598
50 -27 -32.8 0.906 0.974 1.142 2.039
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 Table 6 and Table 7.
Evaporator Temperature Drop
Factors
Performance tables are based on a 10°F (5°C)
temperature drop through the evaporator.
Adjustment factors for applications with
temperature ranges from 6°F to 16°F (3.3°C to
8.9°C) are in Table 6 and Table 7.
Temperature drops outside this 6°F to 16°F
(3.3°C to 8.9°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:
)/0176.0(/0001.0 22 kWCmorBTUFhrft °×°××
per ARI 550/590-98.
As fouling is increased, performance
decreases. For performance at other than
0.0001 (0.0176) fouling factor, refer to Table 6
or Table 7.
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.

OMM 1087-1 AGZ 025D through 190D 7
Table 6, Capacity and Power Derates, Models AGZ 025D to 130D
Altitude Chilled Water Delta
T Fouling Factor
0.0001 (0.0176) 0.00025 (0.044) 0.00075 (0.132) 0.00175 (0.308)
°F °C Cap. Power Cap. Power Cap. Power Cap. Power
Sea
Level
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
2000 feet
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
4000 feet
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
6000 feet
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

8AGZ 025D through 190D OMM 1087-1
Table 7, Capacity and Power Derates, Models AGZ 140D to 190D
Altitude Chilled Water
Delta T Fouling Factor
0.0001 (0.0176) 0.00025 (0.044) 0.00075 (0.132) 0.00175 (0.308)
°F °C Cap. Power Cap. Power Cap. Power Cap. Power
Sea
Level
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
2000 feet
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
4000 feet
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
6000 feet
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
8000 feet
6 3.3 0.979 1.034 0.966 1.031 0.927 1.019 0.859 1.000
8 4.4 0.984 1.036 0.971 1.032 0.932 1.021 0.863 1.002
10 5.6 0.990 1.037 0.976 1.033 0.937 1.022 0.868 1.002
12 6.7 0.993 1.039 0.980 1.035 0.941 1.024 0.871 1.004
14 7.7 0.998 1.041 0.985 1.037 0.945 1.026 0.875 1.006
16 8.9 1.003 1.041 0.990 1.038 0.950 1.026 0.879 1.007
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

OMM 1087-1 AGZ 025D through 190D 9
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 105°F (40.6°C)
•Minimum operating ambient temperature (standard), 35° F (2° C)
•Minimum operating ambient temperature (with optional low-ambient control), -10° F (-23.3°C)
•Leaving chilled water temperature, 40°F to 60°F (4.4° C to 15.6° C)
•Leaving chilled fluid temperatures (with anti-freeze), 15° F to 60° F (-9.4°C to 15.6°C)
•Chilled water Delta-T range, 6 degrees F to 16 degrees F (3.3 degrees C to 8.9 degrees C)
•Part load minimum flow for variable flow systems, varies with unit size; see Table 8 on page 11.
•Maximum operating inlet fluid temperature, 76° F (24° C)
•Maximum non-operating inlet fluid temperature, 100°F (38°C).
Pressure Drop Curves
Evaporator pressure drop curves on the
following page. They apply to either packaged
or remote evaporator applications. Figure 1,
Evaporator Pressure Drops. See following page
for curve cross-reference on the next page
contains the evaporator reference letter and the
minimum and maximum flows allowed for
each unit.
Occasionally the same evaporator is used on
multiple units resulting in overlapping lines.
The minimum and maximum flows for a given
unit will be at the point where the unit
reference number appears.

10 AGZ 025D through 190D OMM 1087-1
Figure 1, Evaporator Pressure Drops. See following page for curve cross-reference
See following page for curve cross-reference and min/max flow rates.
AGZ Water Pressure Drop
A
B
B
C
C
D
D
E
E
F
F
G
G
H
H
I
I
J
J
K
K
L
L
M
M
N
N
O
O
P
P
Q
Q
R
R
S
S
T
T
U
U
A
1
10
100
10 100 1000
Flow Rate (gpm)
Dp (ft)
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U