McQuay MAC 080 C User manual

MAC-C-2004
Air-Cooled Mini Chiller
Models: MAC 080 C/CR
MAC 100 C/CR
MAC 120 C/CR
MAC 150 C/CR
M4AC 080 C/CR
M4AC 100 C/CR
M4AC 120 C/CR
M4AC 150 C/CR

Contents
Nomenclature.................................................................................................................. 2
General Features and Specifications...................................................................... 2 - 3
Chiller Panel Controller .......................................................................................... 4 - 35
Specifications ........................................................................................................ 36 - 39
Performance Table ................................................................................................ 40 - 45
Technical Data ....................................................................................................... 46 - 47
Outlines and Dimensions...................................................................................... 48 - 50
Wiring Diagrams .................................................................................................... 51 - 54
Special Precautions for R407C............................................................................. 55 - 56
Installation ............................................................................................................. 57 - 61
Servicing and Maintenance ......................................................................................... 62
Troubleshooting ........................................................................................................... 63
Schematic Diagram ...................................................................................................... 64
Parts List and Exploded View............................................................................... 65 - 66
Note: Installation and maintenance are to be performed only by qualified personnel who are
familiar with local codes and regulations, and experienced with this type of equipment,
Caution: Sharp edges and coil surfaces are a potential injury hazard. Avoid contact with them.
Warning: Moving machinery and electrical power hazards. May cause severe personal injury or death.
Disconnect and lock off power before servicing equipment.
"McQuay" is a registered trademark of McQuay International. All rights reserved throughout the world.
2003 McQuay International
"Bulletin illustrations cover the general appearance of McQuay International products at the time of publication
and we reserve the right to make changes in design and construction at any time without notice."
1

Nomenclature
M4AC080 C R
Brand Name _ R22 Equipment Air Cooled Norminal Generation
(McQuay) 4 R407C Equipment Chiller Cooling _ Cooling
Capacity R Heating
General Features and Specifications
Refrigerant circuit
The unit has been designed with two separate refrigerant circuits, i.e. it has two compressors. By doing so,
the unit has part loading capabilities, i.e. 0-50-100% of rated capacity. This will improve the reliability and
energy efficiency of the unit, especially during low loading operations. Each circuit is factory brazed and
evacuated before accurately charged with refrigerant to ensure optimum performance. Because each circuit
is separated, there is no danger of crosscontamination should either one of the compressors experiences a
burnt-up. Each circuit is also equipped with a carefully sized thermostatic expansion valve (for cooling only
units) to give optimum performance characteristics. For the heat pump versions, the expansion process is
done with capillary tubes.
Scroll compressors are used in the unit to give quiet and reliable performance over a wide operating
temperature range. However, in order to protect the compressors from damage, a phase protector is
provided to prevent the compressors from rotating in the wrong direction.
Condenser Fan Motor
The unit is equipped with two high air flow propeller fan blades which are made of metal. The fans are
directly driven by weather proof motors, the motors are of single phase type.
Evaporator
The heat exchanger is made of stainless steel plates closely arranged and brazed together (BPHE) to
ensure high heat exchange efficiency. The water flows through the BPHE in a channel on its own, while
because of the two compressors, the refrigerant flows through another two separate channels. The
refrigerant will either be in a counter-flow or parallel-flow with respect to the water, depending on the mode
of operation (cooling or heating).
Safety Protection
The safety protections provided for in the chiller unit are:
a) High and low pressure switches
b) Differential water flow switch
c) Compressor, water pump and fan motor overload protectors
d) Anti-freeze protection sensor
During abnormal condition, the electronic controller will turn off the unit and then display the fault of
operation.
Other than that, the unit also has pressure gauges (analog) for each compressor suction and discharge
pipes. These are useful for detecting abnormal operating conditions, especially during maintenance
services.
2

Water buffer tank & pipe connection
The unit does not come with a water buffer tank. However, the unit does come with an 8 liters expansion
tank.
(A 135L water tank is available as optional item)
The external water piping connection can be made either from the left or right side of the unit. Connection is
done with I1-1/4” female thread couplings for both supply and return pipes.
Anti-freeze protection
The chiller unit has several anti-freeze protection features:
1. Brazed plate heat exchanger anti-freeze
The BPHE has a strip heater around it to prevent water freezing inside.
2. Auto mode
The chiller controller will force-on the unit to the heat mode if the outdoor ambient air temperature
becomes too cold.
Maintenance
In order to facilitate maintenance of the controller, a rocker switch is provided to power-off the supply to the
PCB. However, switching off this switch will not disconnect the main incoming power supply to the chiller
unit.
Coil Guard
The unit also comes with two sets of coil guards (i.e. on the left and right side coils). Each guard is basically
a metal mesh which protects the coil from damage due to a side impact on the coil surface itself.
Fin Coating
The finned tube heat exchanger coil used on the chiller unit is made of staggered rows of 3/8” seamless
copper tubes, mechanically expanded into die-formed louvered fins. The slit openings on the fins enhance
the heat transfer coefficient between the fin surfaces and air.
In order to protect these fins from corrosion, a special fin coating (gold fin) is applied on the surface. This
coating is standard on the heat pump version, whereas it is an option on the cooling only model.
3

Chiller Panel Controller
1. SAFETY CONSIDERATION
Only specially trained and qualified technicians and installers are authorized to install and service this equipment.
1.1 General Installation Recommendations
xOnly supply DC voltage (9-17V, typically 12V, maximum current 200mA) as a power source to the device.
xInput contact voltage supply should limit to 12VDC or 24VAC.
xIsolated all the low voltage wiring (communication bus, etc.) from high voltage power supply wiring.
2. GENERAL DESCRIPTION
2.1 General
The Chiller Panel Controller is designed to control the Chiller operation. This device allows the user to have
customized control for each connected unit.
2.2 Features
The requirements of user friendly and easy to use have been taken into account in designing this Chiller
Panel Controller. It can do the task as follow:
xWhole system configuration
xUnique parameter settings
xOperation status display
xTracing fault record (easy in hardware troubleshooting)
The display is shown in an 8-line graphical LCD display. There are 8 dedicated keys available in the panel,
which allow user to do the following task:
xMenu selection
xNavigation on the screen
xModification of the selected value
During first start-up, the panel will have a default configuration (timer schedule, set point, miscellaneous
settings, etc). User can do the changes on that particular configuration later.
2.3 Panel Position
The Chiller Panel Controller can be installed anywhere, as long as it is easy to accessed by authorized
personnel.
The requirements of installation are:
xAvoid exposure to shocks
xAvoid any source of electromagnetic pollution
xAvoid installation on uneven vertical surface
2.4 Operation Environmental Condition
xTemperature:
-10ºC to 65ºC Operating Temperature
-20ºC to 85ºC Storage Temperature
xRelative Humidity:
0 to 95% Non - Condensing
4

3. HARDWARE DESCRIPTION
9
Front View
Back View
3.1 Key Explanation
The 2 navigation keys permit item selection and modifying the selected value.
ENTER key is used to execute the navigation instruction
ESC key is used to cancel the navigation instruction
Shortcut key to switch the operation mode in the Summary Pages
Shortcut key to trigger ON/OFF in the Summary Pages
Shortcut key to show fault / alarm in the Summary Pages
10
1
3
2
Legend
1 & 2 Navigation key
3 Execute instruction key
4 Cancel instruction key
5 Switching to Heat mode shortcut key
6 Switching to Cool mode shortcut key
7 Toggle ON/OFF shortcut key
8 Show alarm key
9 Graphical LCD display
10 ON/OFF indicator
5
7
8
6
4
Legend
1 & 2 Chiller terminal unit connection
3Not available
4CMOS reset jumper (JH2)
5Chiller bus resistor configuration (JH3)
6Not available
7Not available
8Not available
9Backup battery
5

4. INSTALLATION
4.1 Chiller Bus
Su
pp
orted u
p
to 50 units of Chille
r
Chiller 0 Chiller 1 Chiller 2 5 way wire (CN8)
Chille
r
Communication bus
Chille
r
Panel 1
(Slave)
Chiller Panel 0
(Master)
CHILLER NETWORK
Chiller panel needs to be energized with +12Vdc. The 5 way wires that provided is once on the easiest solution to
establish a communication between the panel and chiller main board (CN8-CN8). If the 5-way wires socket has been
occupied in main board, just using 2 insulation wires connected to the +12Vdc and GND terminal block from main
board to panel can still energize a panel. Beside that, another 2 insulation wired are needed to establish a
communication between panel and chiller main board.
Chiller panel can support maximum up to 50 units of chiller. In the chiller network, duplication of main board unit
address is not allowed. Each chiller main board should have their unique unit address (0 – 50).
For first time running, user need to assign a unique unit address to each main board in the chiller network. User
should follow the procedure below:
xOnly power ON one main board at once time. Make sure not others main boards are energized.
xBy using the panel connected to the main board.
<ENTER> <ENTER>
Summary Pages Main Menu Settings Menu
1. General Set ParameterG7 Unit No
<ENTER>
<ENTER>
Key in “0001” as
password
<ENTER>
xKey in a unique unit address and press ENTER to execute.
xDe-energized the main board and repeat the procedures again until all the main boards have been assigned a unique unit
address
IMPORTANT: Do not assign a same unit address to more than one chiller main board.
RECOMMENDATION: Please select a coherent model (G1 Model) to all the chiller main boards in the same
network
6

4.2 Others Configuration
xJH2 in Chiller panel should let it open (put the jumper header on one pin only) all the time unless user need to
do CMOS reset to that particular panel.
xJH3 should let it open (put the jumper header on one pin only) all the time as well.
xRemember to put in the coin cell battery on the panel. Without the backup battery, the panel will always reset
the time to 12:00am, 1st Jan 2000.
4.3 Installation of the Chiller Panel Controller
xDisconnect the unit and ensure no others unit energy source that supplies the panel.
xOpen the rear panel of the Chiller Panel (insert a ‘flat-head’ screwdriver in the top joint of main casing with
rear panel to open the rear panel)
xPass the necessary wires of the panel across the large opening in the rear panel. Place the rear panel flat
support against the wall and make marks on the wall through the four installation holes (inner or outer).
xDrill four appropriate holes in the marked places.
xAttach the rear panel to the wall and put on the screws on it. Ensure that all cables are passed through the
hole of the rear panel.
xConnect the wires to the corresponding terminal according to the wiring bus network. The power supply and
communication wires must be correctly connected to ensure that the panel works.
xClose the Chiller panel (ensure the bottom joint is aligned for the casing, then complete others joint part.
Ensure that the contacts at the back of the panel are aligned with each others)
BUS WIRING NETWORK
7

5. SOFTWARE DESCRIPTION
5.1 Introduction
The Chiller Panel Controller can be used to control/display the status of Chiller.
Status viewing:
xON/OFF status
xMode (Cooling/Heating/Boiling)
xMode set temperature
xCompressor status (ON/OFF/DEFROST)
xWater in, Water out, Outdoor air and Panel temperature
xChiller Model (Chiller, Heat Pump, Chiller/Boiler, Chiller+Boiler, Heat Pump/Boiler, Heat Pump+Boiler)
xAdvance Parameter settings
xDefrost sensor temperatures
xCompressor Discharge sensor temperatures
xCompressor run times
xIncoming alarm/fault/error
Status settings:
xON/OFF switching
xMode setting (Cooling/Heating/Boiling)
xMode set temperature
xManual entering defrost
xAdvance Parameter settings
xPassword changing
xPanel Option setting (Backlight, Alarm Buzzer, Screen saver, Contrast, Brightness, temperature unit)
xTime and Date settings
x7 day programmable settings
xClearing compressor run time
8

5.2 Menu Structure
Menu Structure Diagram for Chiller
9