McQuay AGZ 030CB Installation Manual
Operation Manual
Air-Cooled Scroll Compressor Chiller
AGZ 030CH through 190CH, Packaged
AGZ 030CB through 190CB, Remote Evaporator
60 Hertz, R-410A
Software Version AGZDU0102G
OM AGZC-1
Group: Chiller
Part Number: 331376301
Effective: February 2010
Supercedes: April 2009
Table of Contents
Introduction........................................3
General Description..................................... 3
Nomenclature .............................................. 3
Ambient Air Temperature Limitations......... 4
Water Flow Limitations ............................... 4
System Water Volume Considerations ......... 5
Glycol Solutions .......................................... 5
Operating/Standby Limits............................ 9
Pressure Drop Curves........................9
oTech II Controller ..................13
Micr
Controller Section Table of Contents ........ 13
Overview ................................................... 14
General Description................................... 14
Setpoints .................................................... 16
Dynamic Defaults...................................... 18
Security...................................................... 19
Control Functions...................................... 19
Unit Enable................................................ 20
Unit Mode Selection.................................. 21
Unit State................................................... 22
Power Up Start Delay................................ 23
Ice Mode Start Delay................................. 23
Low Ambient Lockout............................... 23
Evaporator Water Pump State.................... 23
Leaving Water Temperature (LWT) Reset. 24
Maximum LWT Rate................................. 24
Unit Capacity Overrides ............................ 24
Circuit Capacity Overrides – Limits of Operation
................................................................... 25
Low Ambient Starts ................................... 26
Compressor Sequencing ............................ 26
Manual Compressor Control ..................... 27
Normal Circuit Shutdown.......................... 28
Rapid Circuit Shutdown ............................ 28
Cycle Timers.............................................. 28
Liquid Line Solenoid................................. 28
Hot Gas Bypass Solenoid .......................... 28
EXV Control.............................................. 28
Condenser Fan Control.............................. 29
Alarms and Events.......................... 31
Unit Stop Alarms........................................31
Circuit Stop Alarms....................................31
Circuit Events.............................................33
Clearing Alarms .........................................34
4x20 Display & Keypad.................. 35
Layout ........................................................35
Keys ...........................................................37
Navigation..................................................37
Editing........................................................39
Screen Definitions – MENU......................39
Screen Definitions – VIEW .......................40
Screen Definitions – ALARM/EVENT .....44
Screen Definitions – SET...........................44
Screen Definitions – TEST ........................51
Building Automation System Interface
........................................................... 52
Protocols Supported...................................52
Available Parameters..................................52
Parameter Details....................................... 53
Optional Low Ambient VFD.......... 55
Startup.............................................. 66
Operation......................................... 68
Hot Gas Bypass (Optional) ........................68
VFD Low Ambient Control (Optional)......69
Filter-Driers................................................69
System Adjustment ....................................69
Liquid Line Sight Glass .............................69
Refrigerant Charging .................................69
Thermostatic Expansion Valve...................69
Crankcase Heaters......................................70
Evaporator..................................................70
Phase Voltage Monitor (Optional) .............70
*
©2007 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 construction at anytime without notice. ™® The following are trademarks or registered trademarks of their
respective companies: BACnet from ASHRAE;
L
ONMARK International under a license granted by Echelon Corporation; Compliant Scroll from Copeland Corporation; ElectroFin from AST
ElectroFin Inc.; Modbus from Schneider Electric; FanTrol, MicroTech II, Open Choices, and SpeedTrol from McQuay International. *Unit
Controllers are L
2 AGZ 030C through 190C OM AGZC-1
ONMARK certified with an optional LONWORKS communication module.
Our facility is ISO Certified
LONMARK, LonTalk, LONWORKS, and the LONMARK logo are managed, granted and used by
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
(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,
BOOT Version 3.0F
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.
This manual covers units with Software
Version AGZDU0102G. Installation,
maintenance and service information is in
IMM AGZC (or current, latest dash number)
manual.
BIOS Version 3.62
Scroll Compressor
Air-Cooled
Global
Nomenclature
A G Z - XXX C H
Application
H= Packaged Chiller
B= Chiller with Remote Evap.
Design Vintage
Model Size
(Nominal Tons)
OM AGZC-1 AGZ 030C through 190C 3
Ambient Air Temperature Limitations
Standard/High Ambient Panels
The AGZ-C units for high ambient operation
(105F to 125F 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.
Table 1, Panel Ratings
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.
Voltage
208-230
240
380-460
575
Standard
Standard Options
Optional
Panel
35 5 120 120
35 5 100 100
35 5 65 65
5 5 25 25
VFD
Water Flow Limitations
The evaporator flow rates and pressure drops
shown on page 9 (and following) are for full
load design purposes in order to m
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.
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.
aintain
High Short Circuit
Panel (kA)
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.
When units are operated with flow rates less
than nominal (see Table 8), the “Evap Delta T”
setpoint m
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.
ust be changed proportionally to
High Interrupt Panel w/
Disconnect Swt. (kA)
4 AGZ 030C through 190C OM AGZC-1
System Water Volume
T
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.
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
from Table 2 through Table 5.
2. Flow – Multiply
by the Flow correction factor from Table 2
through Table 5 to determine the increased
evaporator flow due to gly
If the flow is unknown, it can be calculated
from the following equation:
the water evaporator flow
col.
glycolCapacityTons
)(×24
=(gpm) Flow Glycol
TDelta
×
FactorCorrectionFlow
For Metric Applications
– Use the following equation:
(l/s) Flow Glycol
3. Pressure drop -- Multiply the water
pressure drop from page 10 by Pr
essure
Drop correction factor from Table 2
through Table 5. High concentrations of
lene glycol at low temperatures can
propy
cause unacceptably high pressure drops.
4. Power -- Multiply the water system power
by Power correction factor from Table 2 Table 5.
est coolant with a clean, accurate glycol
T
CapacitykW
Delta
18.4
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.
FactorCorrectionFlow
solution hydrometer (similar to that found in
!
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
OM AGZC-1 AGZ 030C through 190C 5
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