DX Remote & Self-Contained A/C v
INSTALLATION • OPERATION
Direct Expansion Systems
Revised: 20170710
L-2086
v
English
v
English
L-2086
Table of Contents
DX Remote & Self-Contained A/C Systems
• Introduction
Drawings and Diagrams ..................................................................4
Air Conditioning Basics ....................................................................4
The Effect of Seawater Temperature ...............................................4
Types of DX Systems .......................................................................4
Subsystems ....................................................................................5
System Controls ..............................................................................5
Condensate Drain ............................................................................5
DX Remote & Self-Contained A/C Systems
• Installation
Installation Procedures ...................................................................6
Electrical System .............................................................................6
Installing The Self-Contained A/C Unit 6
Selecting the Site .............................................................................6
Site Location Checklist ....................................................................7
Mounting the Self-Contained Unit ....................................................7
Installing The Condensing Unit 7
Selecting the Site ............................................................................7
Site Location Checklist ....................................................................7
Mounting the Remote Condensing Unit ...........................................7
Installing The Cooling/Heating Unit 8
Selecting the Site ............................................................................8
Site Location Checklist ....................................................................8
Mounting the Cooling/Heating Unit ..................................................8
Installing the Refrigerant Tubing ......................................................8
Installing the Seawater Cooling System 9
Importance of a Self-Draining System .............................................9
Through-Hull Inlet Fitting .................................................................9
Seacock ...........................................................................................9
Strainer ............................................................................................9
Seawater Pump ...............................................................................9
Manifolds .......................................................................................10
Overboard Discharge .....................................................................10
Seawater Piping ............................................................................10
Bonding ......................................................................................... 10
Installing The Air Distribution System 10
Return Air Grill (RA Grills) .............................................................10
Ducts .............................................................................................10
Discharge Air Grill .......................................................................... 11
Installing the Control Unit 11
The SMX Control ......................................................................... 11
The Rotary Knob Switch Assembly ................................................ 11
Installing the Pump Relay 11
Location ......................................................................................... 11
Voltage and Triggers ......................................................................12
Electrical Connections 12
Three Phase Power ....................................................................... 12
Final Inspection 13
Inspecting the Seawater Cooling System ......................................13
Inspecting the Self Contained Unit ................................................13
Inspecting the Condensing Unit
(Remote Condensing Unit Systems Only) ..................................13
Inspecting the Cooling/Heating Unit
(Remote Condensing Unit Systems Only) ..................................13
Inspecting the Refrigerant Connections
(Remote Condensing Unit Systems Only) ..................................13
Inspecting the Air Distribution System ...........................................13
Inspecting the Control/Switch Assembly and Electrical Wiring ...... 13
Charging the System with Refrigerant 14
Charging a New System ................................................................ 14
Field Charging the System.............................................................14
Removing Refrigerant from the System .........................................15
Initial Start Up 15
DX Remote & Self-Contained A/C Systems
• Operation
Operating Instructions - Rotary Controls 16
SA & SSA Models ..........................................................................16
Operation Instructions - SMX Controls 16
SMX II/SMX Net Operation ............................................................16
Power On .......................................................................................16
System Off ..................................................................................... 16
Selecting Setpoint..........................................................................16
Displaying Temperature ................................................................. 16
Cool Mode ..................................................................................... 17
Heat Mode ..................................................................................... 17
Automatic Changeover ................................................................ 17
Manual Fan Speed Control ............................................................ 17
Automatic Fan Speed Control .......................................................17
Adjusting Brightness ...................................................................... 17
Using The Humidity Control Routine ........................................... 17
Anti-Ice Routine ............................................................................. 17
Owner Maintenance - Routine 18
Condensate Drains ........................................................................18
Air Filters ........................................................................................18
Seawater Connections ...................................................................18
Seawater Pump .............................................................................18
Seawater Strainer ..........................................................................18
Refrigerant Gas ............................................................................. 18
Winterizing the System .................................................................. 18
Trouble Shooting Limited
Descriptions of Figures
18
19
Copyright 2004 Dometic Corporation, All Rights Reserved - Every precaution has been taken in the preparation of this manual to insure its accuracy. However, Dometic Corporation assumes no
responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of this product and information contained herein.
3
v
English
L-2086 Introduction
DX Remote & Self-Contained A/C Systems • Introduction
Warning
This manual contains essential information concerning
the safe and proper installation and operation of your
Cruisair air conditioning system. If there are any statements or procedures in this manual that you do not understand, contact the Dometic Corporation Applications
Department for assistance. Phone
804-746-1313 (8 am - 5 pm US Eastern Time),
Fax 804-746-7248, or email sales@tmenviro-va.com.
Notice
US federal law prohibits the intentional release of refrigerant gases into the environment, including the R -22 refrigerant used in most Cruisair air conditioning systems.
Special care must be taken when installing, charging,
and servicing Cruisair equipment to prevent any loss of
equipment. Only EPA certied technicians with the proper equipment should perform service on the refrigerant
circuit of the system.
Drawings and Diagrams
The gures that are referenced throughout this manual can be
found immediately after the warranty section of the manual. In
addition, some Cruisair equipment will be shipped with specic
installation sheets or wiring diagrams that may supercede the
information located in this manual.
Air Conditioning Basics
The basic principle of an air conditioner is the movement of
heat. In a direct expansion (DX) water-cooled air conditioner,
heat is transferred from the cabin air to the refrigerant gas,
which then releases the heat into the seawater. In reverse cycle
heating (heat pump), the refrigerant ow is reversed and heat
is extracted from the seawater and then discharged into the
cabin.
The heat exchange process relies on the movement of both
cabin air and seawater to effectively work. If air ow or seawa
ter ow is compromised, the efficiency of the system will drop,
and the unit could eventually be damaged, or at least shut
down on one of its safety protection devices.
Part of the cooling process, in addition to lowering the air tem
perature, is the removal of moisture from the air. This lowers
the humidit
helps keep the boat dry, reducing mold growth and other mois
ture related problems.
y, which makes the area feel more comfortable and
-
-
-
best when the seawater temperature is below 90°F (32°C). At
higher water temperatures the unit will operate, but at reduced
capacity. As the water temperature rises, so does the refriger
ant gas pressure. A high-pressure safety switch will shut the
wn if the water temperature gets too hot, or there is a
unit do
loss of cooling water ow.
In heat mode, the opposite is true. As the seawater tem
perature gets colder, there is less heat available and heating
perf
ormance drops. Full heating capacity is available in water
temperatures as low as 55°F (13°C), but drops to about 50%
capacity in 40°F (4.4°C) water. Below this, the refrigerant pres
sure can be so low that the unit will not produce heat, (or may
shut do
wn on low-pressure fault, if this option is installed).
-
-
-
Types of DX Systems
Self-contained units have all major mechanical components of an air conditioning system mounted on one chassis,
including the compr
blower, electrical box and related parts.
The self-contained unit is normally mounted low in the living
area - under a settee or berth, or in a closet or locker. Cabin
air is pulled into the unit, where it is cooled or heated, then dis
charged through ducting to a grill usually located on a bulkhead
high in the compartment.
The refrigerant circuit in a self-contained unit is pre-charged
and sealed at the factory, and no additional charging is needed
at installation. A typical self-contained unit is shown in Figure 1.
Remote systems, also called split-gas, have the air condition
ing components mounted on two separate chassis that are
installed in different locations and are connected by copper
refrigerant tubing.
The condensing unit consists of the compressor, seawater
condenser, and electrical components, and is mounted in the
engine room or other mechanical space.
The cooling/heating unit includes the evaporator coil and a
fan or blower mounted on a drip pan. It is installed in the living
area in a similar manner to a self-contained unit. Two or three
cooling/heating units can be connected to one condensing unit
so that multiple or large cabins can be cooled.
A remote system must be charged with refrigerant after instal
lation by a certied technician. A typical condensing unit is
shown in Figure 2, and Figure 3 is a typical draw-through type
cooling/heating unit.
essor, seawater condenser, evaporator coil,
-
-
-
The Effect of Seawater Temperature
The efficiency of the system is dependent on both the seawater
and cabin temperatures. In cooling, the air conditioner works
4
v
English
L-2086 Introduction
Subsystems
Both self-contained units and remote condensing systems
require subsystems that are purchased separately because of
the many variations and options available. These include the
seawater, air distribution, and control subsystems.
Seawater System
The seawater cooling system consists of an inlet through-hull
tting, seacock (water shut-off valve), strainer, pump, and
overboard discharge tting all connected by hose or piping. If
multiple air conditioning units are served by a single seawater
pump, then a pump relay and water manifold are required.
Air Distribution System
Cabin air is drawn into the self-contained unit or cooling/heating unit through a return air grill. It is then cooled or warmed
and b
lown back into the cabin through a ducting system. The
air should be discharged high in the cabin and away from the
return air grill to ensure good circulation. An air lter is locat
ed on the cooling unit or on the return air grill and must be
cleaned r
egularly.
-
System Controls
Two different types of controls are available, either an electromechanical rotary knob switch assembly or one of the Cruisair
SMX ser
The electromechanical switch assemblies are typically 3-knob
switches that control mode (OFF, FAN, RUN), thermostat
(temperature setting), and fan speed. Other versions include 1
and 2 knob switches for control of “slave” cooling units, and a
4-knob switch for use on systems with auxiliary electric heat.
ies of microprocessor controls.
grammable functions allow the user to customize the system to
suit the specic needs of their boat and boating en
The two SMX control systems available are SMX II and the
SMX Net. Each system consists of:
• Power/Logic (P/L) board - Monitors and controls all func
tions of the air conditioning unit. SMX II and SMX Net hav
different P/L boards and are not interchangeable.
• Keypad/Display - The SMXir is a 10-button user interface
with a digital readout and LED indicators. It is used with
SMX II or SMX Net systems.
• Temperature-Sensing Element - Air temperature is moni
tored by a temperature-sensing element (TSEP) that plugs
into the power/logic board.
• Connecting Cable - The keypad/display connects to the
P/L board with a CX or CXP connecting cable.
SMX Net systems may also have additional network cables
and an outside temperature sensor that plug into the P/L board.
vironment.
-
Condensate Drain
When the air conditioner is running in the cooling mode, moisture is removed from the air by the evaporator coil. This condensation is then caught in a drain pan and must be drained
of
f to a sump or overboard. In humid climates the system can
produce a large amount of condensate water that could cause
signicant damage to your boat if the drain system doesn’t
work properly.
e
-
Cruisair SMX controls are advanced microprocessor systems
that provide a more comfortable environment and better system
protection than mechanical controls. In addition, over 20 pro
-
5
v
English
L-2086 Installation
DX Remote & Self-Contained A/C Systems • Installation
Installation Procedures
This rst section covers installation procedures for Cruisair
direct expansion (DX) air conditioning systems, both self-contained units and remote systems. Please read and understand
the man
ual before attempting to install any equipment.
SMX Installation
For installation instructions for your SMX Control, refer to
SMXII Control Systems (L-2066) or the SMX Net Control Systems (L-2067) manuals.
Electrical System
Cruisair air conditioning systems are available for use with
common power supplies throughout the world. In the United
States and most of North and South America, the systems are
115V or 230V, 60Hz, single phase AC (alternating current). In
Europe and most of Asia, power systems are typically 230V
50Hz single phase.
Compressors larger than 20,000 Btu/hr are only available in
230V single phase, 230V or 380/460V 3 phase. On 380/460V
3-phase units there is often a separate, lower voltage circuit for
the controls and blower, either 115V or 230V. On some power
systems this can be supplied by using one input line and the
neutral. If not, a separate control power feed or a transformer
will be required.
Running and starting loads of an air conditioning system are of
ten the largest electrical loads on a boat. It is important that the
po
wer supply system is large enough to handle these loads,
and is installed properly. Contact an electrician if you are not
sure about the proper wiring procedures. Always follow local
codes or ABYC codes for proper wiring guidelines.
Voltage and Frequency
The voltage rating of a unit is a nominal rating. The actual
voltage in a given location may be higher or lower by as much
as 10% and the system will still operate ne. For example, at
60 Hz, you will sometimes see 110VAC to 120VAC, or 208VAC
to 240VAC, or 440VAC to 480VAC. In a 50Hz environment,
common voltages range from 220V to 240V, or 380V to 415V.
When choosing a system, the voltage and frequency must be
known. While standard 60Hz equipment can often be run at
50Hz, it will experience a 17% drop in performance, however,
50Hz equipment can not be run at 60Hz because the 50Hz
motor will run too fast and cause damage. Seawater pumps
will lose even more performance at 50 Hz due to the nature of
centrifugal pumps.
at 50Hz. If a boat is traveling in 50Hz and 60Hz environments,
then 60Hz equipment should be installed, with special attention
to sizing (especially the pumps) so that the system performs up
to expectations. When running 60Hz equipment at 50Hz, the
voltage should be reduced 17% to prevent overheating a motor.
Installing The Self-Contained
A/C Unit
Safety Warning
A Cruisair self-contained unit should never be placed
such that it can circulate carbon monoxide, fuel vapors
or other noxious fumes into the boat’s living spaces. Do
not install or operate a self-contained unit in the engine
room or near an internal combustion engine. Failure to
follow this precaution could result in serious injury or
death.
Selecting the Site
Self-contained units are designed for built-in installation low in
a closet, under a dinette seat or bunk, or any other convenient
location, with discharge air ducted to a grill high in the com
partment. See Figure 4 for a typical installation.
-
Ignition Protection Warning
Self-contained units do not meet federal requirements
for ignition protection. Do not install in spaces containing
gasoline engines, tanks, LPG/CPG cylinders, regulators,
valves or fuel line ttings. Failure to comply may result in
injury or death.
The self-contained unit must be mounted in a space large
enough to provide clearance on all sides for air circulation. It is
not necessary that the coil be placed directly behind the return
air grill, but an unobstructed path must be provided for the air
to get to the coil. A 2” (50 mm) space in front of the evaporator
coil must be maintained.
Measure carefully for horizontal and vertical clearance prior to
proceeding with installation. It is a good practice to place each
component physically in the area you have selected to ensure
that there is enough space and that connections can be easily
made.
Note that some Cruisair self-contained units have a detachable
electrical box, which can be remotely mounted to save space in
the installation.
-
Dedicated 50Hz units will give full performance at 50Hz, and
should be used when the system is going to be run exclusively
6
v
English
L-2086 Installation
Site Location Checklist
• Unit is not located in an engine room or near an internal
combustion engine
• There is no obstruction of airow from return air grill to coil
• Seawater can be piped to the unit with no loops, dips, or
kinks
• Accessible for service and maintenance, including the return
air lter
• Adequate space for seawater and condensate drain connec
tions
Flat, horizontal and sturdy mounting location
•
• Condensate drain can be run continuously downhill from
unit to overboard tting or sump
• Space is sealed from the bilge or outside air
Mounting the Self-Contained Unit
Before mounting the unit, rotate the blower for discharge in
the desired direction by removing the screws from the blower
mounting ange and any supporting the rear of the blower,
then replacing all screws and remounting the electrical box (if
needed).
Mount the unit on a horizontal surface, and fasten securely
with the hold-down clips provided. If the unit has a detachable
electrical box and you wish to mount it remotely, it should be
securely fastened to a bulkhead or deck.
Route the condensate drain so that it ows freely to an over
board tting or sump. Do not permit condensate to puddle in
the bilge
condensate drains, one at each end. It is recommended that
you use both drains for best results, but if you choose to use
only one condensate drain, place the included plug in the other
hole.
Once the unit is correctly mounted, proceed to section titled
“Installing The Seawater Cooling System.”
. Note that most Cruisair self-contained units have two
-
Installing The Condensing Unit
This section applies only to remote condensing unit systems. If
you are installing a self-contained unit, skip this section and go
to “Installing The Seawater Cooling System.”
Selecting the Site
Cruisair condensing units are designed to be installed in any
convenient location. The unit is normally placed in the engine
room or other machinery space, but it can be located in the
living areas. The condensing unit will produce condensation so
a drip pan may be needed. The space around the unit can be
insulated to reduce noise if desired. The unit is internally cooled
and does not require ventilation.
-
Ignition Protection Warning
Most Cruisair remote condensing units meet federal
requirements for ignition protection. However, there are
some condensing units, such as those with 3 -phase
compressors, that are not ignition protected. Do not
install non-ignition protected units in spaces containing
gasoline engines, tanks, LPG/CPG cylinders, regulators,
valves or fuel line ttings. Failure to comply may result in
injury or death.
Site Location Checklist
• Adequate space for access to refrigerant, and seawater and
electrical connections
• Accessible for service and maintenance
• Flat, horizontal surface
• Away from direct spray from engine air intakes or water
washdown
• Maximum refrigerant tube run is 50ft (15m)
Mounting the Remote Condensing
Unit
Orient the unit so the refrigerant, electrical connections and
service ports are accessible.
On models with a plywood base, simply drill 4 mounting holes
through the base in appropriate locations and fasten the unit
with screws or bolts. Do not remove the plywood base or shock
mounts as they are part of the vibration and noise isolation
built into the unit.
Some models utilize a drain pan with bottom or side conden
sate drains. Screw or bolt through all corner holes of the pan to
mount the unit.
Do not remove any covers, caps or ttings that may expose any
wiring or refrigerant. Only remove these items when you are
ready to complete the installation. Removal of any covers may
result in damage to the electrical components. Removal of the
caps or ttings may result in refrigerant loss.
-
7
v
English
L-2086 Installation
Installing The Cooling/Heating
Unit
This section applies only to remote condensing unit systems. If
you are installing a self-contained unit, skip this section and go
to “Installing The Seawater Cooling System”.
Safety Warning
A Cruisair cooling/heating unit should never be placed
such that it can circulate carbon monoxide, fuel vapors
or other noxious fumes into the boat’s living spaces.
Failure to follow this precaution could result in serious
injury or death.
Ignition Protection Warning
Cooling/heating units do not meet federal requirements
for ignition protection. Do not install in spaces containing
gasoline engines, tanks, LPG/CPG cylinders, regulators,
valves or fuel line ttings. Failure to comply may result in
injury or death.
Safety Warning
Do not terminate air handler condensate drain lines within 3 feet (1m) of any outlet of engine exhaust systems,
nor in a compartment housing an engine or generator,
nor in a bilge, unless the drain is properly connected to a
sealed condensate or shower sump pump. Exhaust and/
or bilge fumes can travel up a drain line and mix with the
return air blowing into living areas.
Selecting the Site
Because of the diversity of available cooling/heating units,
there is a great deal of exibility in selecting the location. Typically the unit is located low in the cabin, with the discharge grill
as high as possib
from the return air for proper air circulation.
There are basically 2 types of cooling/heating units, drawthrough and blow-through. Figures 5 and 6 show typical cool
ing/heating unit installations.
1
. Draw-through units typically have squirrel-cage blowers
that are strong enough to push air through ducting to the
discharge grill.
2. Blow-through units use a fan or blower to blow air across
the evaporator coil for direct discharge through a grill. The
discharge air from these units should not be ducted.
le for good cooling performance and away
-
It is not necessary for the evaporator coil to be placed directly
in front of the return air grill, but an unobstructed path must be
available for the air to get to the coil. A 2” (50mm) space in front
of the evaporator coil must be maintained.
Site Location Checklist
• Unit is not located in an engine room or near an internal
combustion engine
• There is no obstruction of airow from return air grill to coil
• Accessible for service and maintenance, including the return
air lter
• Adequate space for and condensate drain connections
• Flat, horizontal and sturdy mounting location
• Condensate drain can be run continuously downhill from
unit to overboard tting or sump
• Space is sealed from the bilge or outside air
• Maximum copper tubing run between condensing unit and
cooling unit is 50 ft. (15m)
Mounting the Cooling/Heating Unit
Mount the cooling/heating unit so that the condensate drip pan
is beneath the unit. Some models require a mounting frame or
mounting leg kit, which is supplied separately. Other models
have integral mounting frames or the condensate pan itself
is the mounting base. See individual spec sheets for specic
guidelines.
Route the condensate drain hose steadily downhill so that the
condensate ows freely to an overboard tting or sump. Do not
permit condensate to puddle in the bilge. Some Cruisair cool
ing/heating units have two condensate drains, one at each end.
It is recommended that you use both drains for best results. If
you choose to use only one condensate drain, plug the other.
Be careful when bending the extension tubes on the evapora
tors. Do not allow the tubing to kink and do not twist or bend
the tubing at the connection point close t
may crack. If bending by hand make large radius bends. Use a
tube bender if a tight bend is required.
o the coil or the joints
-
-
Installing the Refrigerant Tubing
Use refrigerant-grade soft copper tubing of the correct sizes to
connect the cooling/heating unit to the condensing unit. Note
that tee-joints will be needed if more than one cooling/heat
ing unit is used with a single condensing unit. The tees must
be properly oriented to provide best efficiency. (See Figure 7,
Refrigerant Line Size Chart.)
-
Some cooling/heating units are designed for overhead use,
and may be mounted below a ybridge console or seating. This
setup will draw return air through the overhead, with discharge
air either directly blown back down into the area or ducted to
overhead grills.
Only use refrigerant-grade seamless soft copper tubing. Never
use any type of plastic or rubber hose or tubing.
The refrigerant tubes can run uphill, downhill or sloping as re
quired and can have as many bends as necessary. Avoid sharp
bends that could result in kinks in the tubing. The cooling/heat-
8
-
v
English
L-2086 Installation
ing unit has additional tubing to help with installation. Take care
when bending this tubing as it can easily kink or crack a weld
joint resulting in refrigerant loss.
A self-draining seawater system will allow air in the piping to
rise naturally through the pump and then be expelled. It will
also make winterizing the system much easier.
Both refrigerant lines should be insulated individually.
When putting the recommended closed cell foam insulation
over the tubes, cover the ends of the copper tubes to prevent
foreign material and moisture from getting inside the copper
tubing. After checking for leaks, insulate the connecting are
nut joints and tee-joints to prevent secondary condensation.
Secure tubing every 3 feet (1m) as necessary for support.
The copper tubing is connected to the condensing unit and
cooling/heating unit with are joints. To prevent refrigerant
leaks, ares must be formed correctly with the proper aring
tool. Only 45-degree single ares should be used.
Flares should be made following the instructions of the partic
ular aring tool. Make sure to slide the are nut onto the tube
before aring. A drop of oil on the tube can ease the aring
process. The surface of the are face must be smooth and free
of defects to ensure that the joint won’t leak. The are should
be large enough in diameter to ll the are nut completely.
Once you have completed installing the cooling/heating unit
and have made the refrigerant connections between the cool
ing/heating unit and the condensing unit, proceed to on to the
next section “Installing The Seawater Cooling System.”
-
-
Installing the Seawater Cooling
System
The following installation instructions apply to both self-contained and remote condensing units.
Importance of a Self-Draining System
Along with restricted ducting, a poorly plumbed seawater
system is one of the most common installation problems on
marine air conditioners. When water ow is lost, not only will
the air conditioning units no longer cool or heat, the units and
the pump could be damaged from running with no water ow.
When using a centrifugal seawater pump, it is imperative that the
seawater piping be routed continually uphill from the through-hull
inlet to pump and to the condenser, then smoothly up or down
to the overboard discharge, without any dips or loops, and with
only one high point in the system. This is said to be self-draining
because all water would drain out of the piping if the boat were
lifted out of the water.
Whenever air gets into the system, which can happen in heavy
seas or a sharp turn, it can become trapped in the pump.
Because a centrifugal pump cannot pump air, ow through the
system is lost.
Figure 8 shows a properly plumbed system and some common
mistakes.
Through-Hull Inlet Fitting
A separate through-hull tting must be installed for each air
conditioning seawater pump. Do not attempt to draw water from
an engine, generator, or other through-hull tting.
A scoop-type through hull should be installed facing forward,
and as far below the water line and close to the keel as possi
ble.
Drill a properly sized hole for the through-hull tting. Bed the
scoop with marine sealant designed for underwater use, and
tighten the nut onto the through-hull to secure it.
-
Seacock
A full ow seacock should be installed directly onto the
through-hull tting. Use Threaded-seal tape or other sealant on
the threads. The seacock must be accessible and easy to close
in case of emergency, or to clean the strainer.
Strainer
A seawater strainer must be installed between the seacock
and the pump, and should be situated to provide easy access
for cleaning. The strainer must be located vertically above
the seacock and below the pump so any air that gets into the
strainer can get out.
Make sure the water ow through the strainer is in the correct
direction. Some strainers have an arrow that shows correct ow
direction.
Mount the strainer to a bulkhead so it is properly supported
before connecting hoses. Use Threaded-seal tape or other
sealant on pipe threads.
Seawater Pump
Centrifugal pumps are not self-priming, and must be mounted so that they are below the heeled waterline in any given
operating condition. The pump should be accessible for future
service.
Mount the pump so the outlet is directed upward so air can
escape. The head on some pumps can be rotated to allow
mounting on a vertical bulkhead. See Figure 9.
Self-priming pumps are available if the pump cannot be mount
ed below the waterline.
Required seawater owrate is 4 gpm per ton
(12,000 Btu/hr) of total system capacity.
-
9
v
English
L-2086 Installation
Manifolds
If a pump is serving multiple units, then a seawater manifold
will be needed to supply water to all units. This can be as
simple as a TEE for 2 units, or a custom made manifold for up
to 7 or 8 units.
It is very important to consider manifold orientation so that all
air conditioning units get the proper ow of water. See Figure
10 for manifold information.
need to be larger than the outlet pipe size. Do not use
pump connections to determine hose size.
• The “Pump Inlet” recommended pipe size includes all
ttings and hose (through-hull, seacock, strainer, etc.) up to
the pump inlet connection. The “Pump Discharge” includes
all piping/hose and ttings from the pump to the air condi
tioning unit or manifold, and to the overboard discharge.
• Use larger hose when the run is longer than 16 feet (5m).
-
A manifold can also be used on the outlets of the air condition
ing units when using a single overboard discharge.
Overboard Discharge
The overboard tting should be located between 1 to 2 inches
(25 - 50 mm) above the water line. This is to facilitate visual
conrmation of water ow, but also close enough to the water
to minimize splashing noise.
If the overboard tting must be installed below the heeled water
line, then a valve must be installed per ABYC standards.
Seawater Piping
• Only use reinforced marine grade hose or other suitable
piping (PVC, CPVC, Cupronickle, or Stainless steel).
• Double clamp all hose connections.
• Use only plastic, bronze, or stainless steel ttings (do not
use brass).
• Avoid loops or dips in the hose runs.
• Make sure enough hose is used to allow future removal of
components.
-
Bonding
Bond all metallic parts (through-hull ttings, valves, strainer,
manifolds, etc.) that are in contact with seawater to the vessel’s
bonding system in accordance with ABYC standards E-8 and
E-9. Items should only be bonded or grounded once. If an item
is in contact with an electrically grounded part (pump head or
seawater condenser) then it should not be bonded again.
Installing The Air Distribution
System
The following instructions apply to both self-contained units
and remote condensing systems, except as noted. Refer to
Figure 11 for proper grill and duct sizes.
Return Air Grill (RA Grills)
The return air grill should be located so there is unobstructed
airow to the unit’s evaporator coils. Installing ducting between
the return air grill and the air conditioning unit is not normally
necessary and should be avoided. The grill may be located on
a side opposite the evaporator coil so long as airow to the coil
is unobstructed.
• Use the correct size hose, ttings, and components. See
the table below for proper seawater sizing. Note that the
pump inlet piping (including through-hull and strainer) may
An air lter must be used to prevent the evaporator coil from
collecting dirt and lint. The lter can be located at the evap
orator coil or at the grill. Only one lter should be used. Most
self-cont
lter, but if the lter is not easily accessible, use a lter on the
return air grill.
ained units and cooling units are supplied with an air
Ducts
Insulated exible ducting or built-in ducting may be used to
route air from the blower to the discharge grill. Note that blow
through cooling units are installed directly behind the discharge
grill, and ducts are unnecessary. Likewise, with some overhead
cooling/heating units, air is discharged directly into the com
partment without ducts.
Ducting Guidelines
Secure duct to blower or transition box (plenum) with screws
and duct tape. When using insulated exible ducting, make
sure inner duct is secured and sealed to adapter before pulling
insulation over connection.
10
-
-
v
English
L-2086 Installation
Plenums, or transition boxes are used with exible ducting to
split and route the discharge air as needed. Figure 12 shows
several plenum congurations.
• Ducting must be properly sized for the airow. If the duct run is
longer than 10 feet (3m), use the next larger duct size.
• Use of insulated duct is recommended, and is mandatory
when used in high heat areas or where condensation would
be a problem.
• Run exible ducting tightly and smoothly, with as few bends
as possible.
• Keep ducts as short as possible.
• Support ducting to prevent sagging during boat operation.
• Trim excess ducting before attaching to transition adapters.
• Make sure ducting is not crushed or kinked.
• Use a exible transition duct between blower and any builtin ducting.
• If possible, rotate blower to keep duct run as short and
direct as possible.
Discharge Air Grill
When used with exible ducts, a grill plenum should be incorporated behind the discharge grill. Location of this grill should
be as high as possib
ow between discharge and return encompasses as great an
area as possible in the cabin. Care should be taken to avoid
“short cycling,” a situation where the conditioned air is returned
to the coil without being substantially affected by the cabin air.
le in the cabin, and oriented so that air
Installing the Control Unit
The SMX Control
If your system has SMX controls, refer to the appropriate SMX
II or SMX Net Control System Installation/Operation Manual.
be rear access with sufficient clearance for the wiring and the
protective cover. The thermostat bulb is on a 10 ft (3m) long
capillary tube, and the switch assembly must be installed close
enough to the unit so the bulb can be mounted in the return air
path.
Remote condensing systems use SA type switches which
have terminal strips that must be mounted to the back of the
bulkhead where all eld wiring terminates. This location must
be easily accessible for wiring connections and service.
One and two-knob slave switch assemblies should be installed
in the cabin where the slave cooling unit is operating.
Mounting
Cut a hole in the bulkhead using the template shipped with the
switch, or one from the back of this manual. See Figures 13a
and 13b for templates and switch dimensions.
Attach the terminal strip to an accessible location on the back
of the bulkhead (remote systems only). Self-contained systems
have a 10-foot (3m) harness with a plug that connects to the
self-contained unit.
Carefully route the thermostat bulb from the switch to the
return air path of the unit so the capillary tube does not get
kinked. The large bulb must sense the return air, and not touch
the evaporator coil. If a second smaller “anticipator” bulb is
attached to the main bulb, it should be installed into the dis
charge duct.
After making all wire connections, install the protective plastic
cover (remote systems only) over the terminal strip. Next install
the plastic cover over the back of the switch assembly (remote
and self-contained systems) and mount the switch to the bulk
head with the 4 screws provided.
-
-
Installing the Pump Relay
The Rotary Knob Switch Assembly
The following instructions apply to both self-contained and
remote condensing unit systems using a rotary-knob switch
assembly.
Warning
The rotary knob switch assembly switches line voltage
(115 or 230VAC) and in many case full power of the unit.
The selected mounting location must be safe in regards
to voltage as well as heat produced by the switch assembly.
Location
The switch assembly should be mounted on a vertical bulkhead where it can easily be seen and reached. There should
The following instructions apply to both self-contained and
remote condensing unit systems that have multiple A/C units
served by a single seawater pump. If you only have one A/C
unit, or each unit has it’s own seawater pump, then skip to the
next section.
Location
The pump relay is generally located in the engine room near
the seawater pump, but it can be mounted anywhere that is
convenient and accessible. It must be in a dry location, away
from any possible water spray, with room for some heat dissi
pation.
11
-
v
English
L-2086 Installation
Warning
PR3X and PR8X pump relays are certied ignition
protected. However, pump relays with electromechanical
relays or contactors (such as 3-phase pump relays) are
not ignition protected and must never be installed in
spaces containing gasoline engines, tanks, LPG/CPG
cylinders, regulators, valves or fuel line ttings. Failure to
comply may result in injury or death.
Voltage and Triggers
PR3X and PR8X pump relays are identical in operation. When
the rst A/C unit turns on, the pump relay will turn on the seawater pump, and the pump will stay on until the last A/C unit
shuts do
The PR3X can operate up to 3 A/C units, and the PR8X can
operate up to 8 A/C units. Both can operate 115V and 230V
pumps.
Triggers are used in the pump relays to isolate the signals from
each A/C unit. Some pump relays come with pre-installed trig
gers, or you can buy triggers separately. Triggers come in 115V
and 230V
Both 115V and 230V triggers can be used in a single pump
relay if the system requires it.
wn.
-
, and must match the control voltage of the A/C unit.
• If there is only one a/c unit, the seawater pump does not re
quire a separate breaker, but make sure the breaker is siz
for the combined load of the unit and the pump. If multiple
a/c units are supplied by a single pump, then a pump relay
will be needed, and will require it’s own circuit breaker.
• All units must be grounded to minimize the potential hazard
of electrical shock and personal injury.
• All metallic ttings in the seawater system that are isolated
from the a/c unit or pump by rubber hose should be bonded
per ABYC standards E-8 and E-9.
• On larger F-type condensing units a fuse can be added to
protect the fan and control wires.
-
ed
The trigger is simply a relay that closes when the A/C unit turns
on. Because each trigger is isolated, the polarity of the signals
from the A/C units does not matter.
Electrical Connections
Warning
Make sure all power is off before opening any
electrical box.
The following guidelines apply to both self-contained and
remote condensing unit systems:
• Failure to properly ground and bond the system will void
warranty.
• All electrical connections should be made within the
electrical junction boxes supplied with the units. Most units
have terminal strips that are labeled or have color-coded
wiring. Open terminal strips (such as supplied with switch
assemblies) require that the included terminal strip covers
be installed over the strip and switch back after installation
is complete.
• Wiring diagrams are included in the back of this manual and
under the cover of the electrical boxes on all units. Contact
Dometic Corporation if you are not sure if you have the
correct diagrams.
• Each air conditioning unit requires it’s own dedicated circuit
breaker, of the appropriate size. See the table below for
suggested circuit breaker and wire sizing.
Note
Always follow ABYC guidelines or local codes when selecting
breakers and wire sizes.
Three Phase Power
Some larger compressors and pumps have 3 phase motors
that will run forwards or backwards depending on the wire
connections. Reciprocating (piston type) compressors can run
either way without any problem, but scroll compressors and
centrifugal pumps are direction sensitive and must be wired
so the motors run the correct direction. If running backwards,
Scroll compressors will usually make loud, unusual noises and
will not perform properly.
12
Loading...