Mars Air Systems L-2254 User Manual
vector compact
Installation & Operation
Direct Expansion Systems
Revised: 7-18-05
L-2254
TABLE OF CONTENTS
Table of Contents
IF YOU HAVE A DIGITAL CONTROL......................................................................................................... 3
Introduction
How It Works ............................................................................................................................................... 4
Installation
Unpacking and Inspection.......................................................................................................................... 5
Safety Considerations ................................................................................................................................ 5
Placement of System ................................................................................................................................. 5
Condensate Drains..................................................................................................................................... 6
Blower Assembly ........................................................................................................................................6
Mounting Brackets ...................................................................................................................................... 6
Supply & Return Air Grilles and Transition Boxes...................................................................................... 6
Ducting........................................................................................................................................................ 6
Seawater Pump and Plumbing .................................................................................................................. 7
Electrical Connections, Grounding and Bonding ....................................................................................... 8
Manual Control Panel (MCP) Installation ................................................................................................... 8
Installation Checklist (Review prior to installation) ..................................................................................... 9
Operation
Mechanical Control Panel (MCP) Operation............................................................................................ 10
Quick Start Operations Checklist .............................................................................................................10
Troubleshooting
General Troubleshooting .......................................................................................................................... 11
Digital Controls Troubleshooting .............................................................................................................. 12
MCP Mechanical Control Panel Troubleshooting ....................................................................................14
Maintenance
Winterization ............................................................................................................................................. 15
Manufacturers Limited Warranty Agreement 16
Description of Figures 17
Distributor Listing 27
IF YOU HAVE A DIGITAL CONTROL
Please refer to either the Elite Control manual (L-2230) or the Passport I/O Control manual (L-2231) for installation and
operation of those digital control panels. Mechanical control information and wiring diagrams for both types of controls
are in this manual.
Copyright 2005 Dometic Environmental Corporation, All Rights Reserved - Every precaution has been taken in the preparation of this manual to insure its accuracy. However, Dometic
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.
L-2254
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INTRODUCTION
Congratulations on the purchase of your Marine Air
Systems’ Vector Compact
which of the following features was the reason for your
purchase of this air conditioner, we are sure it will meet
your needs and will give you many years of efficient and
trouble free use. The Vector Compact self-contained
direct expansion air conditioners are designed for marine
applications incorporating the following features:
• Patented compact design with the condenser coil in
the evaporator shroud
• High efficiency rotary compressor or scroll (24K)
compressors
• Cupronickel condenser coil
• Enhanced fin designed evaporator coil
• 2" deep drain pan with multiple condensate drain
locations
• Anti-vibration base pad
• Pre-charged and pre-wired systems for easy
connections
• Rotatable blower assembly
• Charge Guard® ensures environmental protection
and system integrity
This manual is intended to provide the information
necessary to ensure proper installation, operation, and
maintenance of the unit. The figures that are referenced
throughout this manual can be found immediately after
the warranty section. Improper installation or misunderstood operating procedures can result in unsatisfactory
performance and/or premature failure of these units, so
before proceeding
The Vector Compact units are covered under the existing
Dometic Environmental Corporation (Dometic) warranty
policy contained in this manual. In the interest of product
improvement, Dometic’s specifications and design are
subject to change without prior notice.
®
air conditioner. No matter
please read this manual completely.
Clean Air Act Amendments of 1990
[Title VI - Section 608(C-1)]
“Effective July 1, 1992, it shall be unlawful for any
person, in the course of maintaining, servicing, repairing,
or disposing of an appliance or industrial process
refrigeration, to knowingly vent or otherwise knowingly
release or dispose of any Class I* or Class II** substance used as a refrigerant in such appliance (or
industrial process refrigeration) in a manner which
permits such substance to enter the environment. De
minimis releases associated with good faith attempts to
recapture and recycle or safely dispose of any such
substances shall not be subject to the prohibition set
forth in the proceeding sentence.”
* Class I substances include CFC-12
** Class II substances include HCFC-22
Marine Air Systems
Marine Air Systems (MAS) is a product of Dometic
Environmental Corporation. Dometic is a recognized
leader in the design and manufacture of high-performance comfort control systems, refrigeration products
and battery charging products for demanding environments, including commercial and recreational marine
craft, vehicles and other applications. We offer an
unparalleled scope of products, dealer networks, applications support, engineering resources and production
capabilities throughout the world. Our team has many
years of experience in the design, manufacture, application and support of our products. Our practical experience and design capability allows our application
engineers and sales representatives to offer optimum
solutions for your environmental control requirements.
Product lines also include well known Cruisair, Grunert,
and Sentry.
How It Works
Your self-contained air conditioner consists of four main
components and a refrigerant gas circulating through the
system. The BLOWER draws warm cabin air across the
fins on the EVAPORATOR where the heat from the air is
transferred to the refrigerant in the evaporator coil. As
the refrigerant evaporates from a liquid into a gas it
absorbs the heat from the cabin air. The COMPRESSOR
then compresses the refrigerant gas and pumps it
through the outer tube in the CONDENSER COIL. The
seawater pump circulates cool seawater through the
inner tube in the condenser coil, this cools the refrigerant and condenses it into a liquid. The heat from the
refrigerant is exchanged to the seawater and discharged
overboard. The liquid refrigerant is then passed through
the EVAPORATOR COIL and the cycle repeats. Removing heat from the cabin air lowers its temperature. The
cooled air is blown through the ducting and out the
supply air grille(s). For reverse cycle heating, the refrigerant flows in the opposite direction through the reversing
valve. Heat is transferred from the seawater in the
condenser coil to the refrigerant and then to the air
blowing through the evaporator into the cabin. Seawater
temperature will directly affect the a/c unit’s efficiency.
This a/c unit can effectively cool your boat in water
temperatures up to 90°F and heat in water temperatures
as low as 40°F. See Figure 1.
L-2254 Introduction
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INSTALLATION
Unpacking and Inspection
When the equipment is received, all items should be
carefully checked against the packing list to ensure all
cartons have been received. Move units in the normal
“up” orientation as indicated by the arrows on each
carton. Examine cartons for shipping damage, removing
the units from the cartons if necessary. If the unit is
damaged, the carrier should make the proper notation on
the delivery receipt acknowledging the damage.
CAUTION: When unpacking and installing the 3-knob
control (if mechanical option is used), care must be
taken not to kink or break the copper cap tube when
uncoiling the sensing bulb. The cap tube is hollow and
kinking or sharp bends will inhibit system operation.
Safety Considerations
VERY IMPORTANT:
in the bilge or engine room areas. Insure that the
selected location is sealed from direct access to
bilge and/or engine room vapors. Do not terminate
condensate drain line within three (3) feet of any
outlet of engine or generator exhaust systems, nor in
a compartment housing an engine or generator, nor
in a bilge, unless the drain is connected properly to a
sealed condensate or shower sump pump.
Installation and servicing of this system can be hazardous due to system pressure and electrical components.
When working on this equipment, always observe
precautions described in the literature, tags and labels
attached to the unit. Follow all safety codes. Wear safety
glasses and work gloves and place a fire extinguisher
close to the work area. The following is a summary of
the labels on the unit:
Danger
Electrical shock hazard. Disconnect voltage at main
panel or power source before opening any cover.
Failure to comply may result in injury or death.
Never install your air conditioner
Notice
This component is charged with hydrochloro-fluorocarbon
(HCFC) refrigerant R22. Effective July 1, 1992 it shall be
unlawful for any person to knowingly vent or otherwise
knowingly release any class 1 (CFC) or class 2 (HCFC)
substance as a refrigerant in a manner which permits
such substance to enter the atmosphere per the clean
air act of 1990. Public law 101-549 Title IV Section 608C. Failure to comply may result in severe penalties,
including fines and imprisonment.
Warning
To minimize the hazard of electrical shock and
personal injury, this component must be effectively
grounded. Refer to the installation guidelines for
further information.
Caution
High compressor temperature is normal.
Do not touch.
Placement of System
Selecting a good location for your air conditioner is the
most important part of your preparations. Be sure to
consider the size of the area you are cooling, the air
distribution needs, and the size of the unit you have
chosen. Keeping in mind that cool air has a tendency to
fall, it is highly recommended that you locate the supply
air grille as high as possible in the cabin. See Figures 2
and 3.
The Vector Compact unit should be installed as low as
possible, BUT NEVER IN THE BILGE OR ENGINE
ROOM AREAS. INSURE THAT THE SELECTED LOCATION IS SEALED FROM DIRECT ACCESS TO BILGE
AND/OR ENGINE ROOM VAPORS. Installing the unit as
low as possible (such as under a V-berth, dinette seat or
bottom of a locker) and ducting the supply air as high as
possible, creates an ideal airflow condition. This type of
installation will prevent short or premature cycling.
Warning
This component does not meet federal requirements for ignition protection. Do not install in
spaces containing gasoline engines, tanks, LPG/
CPG cylinders, regulators, valves or fuel line
fittings. Failure to comply may result in injury or
death.
L-2254 Installation
The unit should be positioned on a firm, level, horizontal
surface and the condensate drain line should run
downward from the unit to a suitable drain location. Plan
all connections which must be made including ducting,
condensate drain, seawater in and out, electrical power
connections, location of control, and seawater pump
placement, to assure easy access for routing and
servicing.
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Minimum Tools Required
• Screws drivers
• Pliers
• Pipe wrenches
• Wire cutters/crimpers
• Drill and assorted bits
• Jig saw
• Duct tape
• Electrical tape
• Teflon tape
• Beding compound to seal thru hull fittings
• Hardware to secure unit, pump, strainer, grilles &
control panel
Condensate Drains
The condensate drain pan is 2" high with up to four drain
locations. During conditions of high humidity, condensate
may be produced at a rate of approximately 1/2 gallon
per hour. With this in mind, it is important to route
condensate drains downward to a sump pump. It is not
recommended to route condensate drains to the bilge.
After the condensate drain installation is complete, test
the installation by pouring a quart of water into the pan
and checking for good flow. See Figure 4.
utilized. This will help to prevent water from standing in
the pan. See item 7 for instructions on connecting two
drain lines.
IMPORTANT! Do not terminate condensate drain line
within three (3) feet of any outlet of engine or generator
exhaust systems, nor in a compartment housing an
engine or generator, nor in a bilge, unless the drain is
connected properly to a sealed condensate or shower
sump pump.
Blower Assembly
With the Vector Compact you can achieve multi-directional supply air discharge from a single unit by rotating
the blower to the desired location. It is ideal for tight
installations as 130° of rotation are available with which
to position the blower. Its advanced design allows the
blower to be easily removed for rotating or servicing by
removing the two mounting ring screws and the screws
attaching the blower to the drain pan. Rotate the blower
to allow the most direct flow of air to the supply air grille.
Reinstall the mounting screws. Plug any unused screw
holes in the blower to prevent air loss.
Mounting Brackets
The a/c unit is supplied with a base pan that also serves
as a condensate pan. Mounting clip brackets are provided to secure the base pan onto a flat, horizontal
surface. See Figure 5.
For installation of the condensate drain:
1. Remove the aft facing watertight plug from the base
pan of the a/c unit (see note).
2. Slip the solid washer and the liquid-seal washer onto
the PVC fitting in that order.
3. Connect the fitting through the exposed hole in the
base pan with the locking nut.
4. Securely tighten with two (2) wrenches to provide a
proper seal.
5. Attach a 5/8" I.D. reinforced hose to the hose barb and
secure with stainless steel hose clamps.
6. Install the condensate drain hose downhill from the
unit and aft to a sump.
7. Two drain fittings may be used and the hoses teed
together provided there is a minimum 2" drop form the
bottom of the base pan to the tee connection.
Note: The reason to use the "aft facing" drain location is
so that water will tend to drain out of the pan when the
vessel is under way. However, the boat owner should
inspect the pan when the vessel is at rest. If water is
collecting in the pan along an edge other than "aft
facing", then the drain on that edge should also be
Supply & Return Air Grilles
and Transition Boxes
Install the supply air grille as high as possible in a
location that will provide uniform air distribution throughout the cabin, grille louvers should be directed upward.
The return air grille should be installed as low and close
to the a/c unit as possible to insure direct uninterrupted
airflow to the evaporator. The return air grille should have
a minimum four inches (4") of clearance in front of it,
free from any furniture or other obstructions. In no
instance should a supply air discharge be directed
towards a return air grille, as this will cause the system
to short cycle. Allow for adequate clearance behind the
supply air grille(s) for the transition box and ducting
connection. The table in Figure 8 shows minimum grille
sizes. See the MAINTENANCE section of this manual for
return air filter cleaning instructions.
Ducting
Good airflow is critical for the performance of the
entire system. It is highly dependent on the quality of
the ducting installation.
straight, smooth and taut as possible minimizing the
number of 90° bends (two tight 90° bends can reduce
airflow by 25%). The table in Figure 8 shows minimum
The ducting should be run as
L-2254 Installation
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duct diameters and their corresponding supply and
return air grille minimum area in square inches. If a
transition box is used, the total area of supply air ducts
going out of the box should at least equal the area of
the supply duct feeding the box. To calculate the square
inch area of a round duct, multiply the radius by itself (r
and multiply that number by 3.1416(π). See Figure 8.
The following is a summary of proper ducting connections:
1. Pull back the fiberglass insulation exposing the inner
mylar duct hose.
2. Slide the mylar duct hose around the mount ring until
it bottoms out.
3. Screw 3 or 4 stainless steel sheet metal screws
through the duct hose into the transition ring.
Make sure to catch the wire in the duct hose with the
heads of the screws. Do not use band clamps, as the
hose will slide off.
4. Wrap duct tape around the ducting and ring joint to
prevent any air leaks.
line and as close to the keel as possible in any
application, but especially on a sailboat, to keep the
intake in the water when the boat heels over so that
air does not get into the system.
2
proper installation.)
)
The speed scoop intake must face forward and not be
shared with any other pump. A seawater strainer is
mandatory between the shut off valve (seacock) and the
pump to protect the pump from any foreign matter.
(See Figure 7 for
Failure to install a seawater strainer will void the
pump warranty.
stalled with an upward incline from the speed scoop &
seacock, through the strainer, to the inlet of the pump
and then up to the inlet of the a/c unit’s condenser coil.
The discharge from the a/c unit should then run to the
seawater outlet thru-hull fitting which should be located
where it can be visually checked for water flow and as
close as practicable to the waterline to reduce noise. All
hose connections shall be secured by means of double/
reversed stainless steel hose clamps. Use teflon tape on
all threaded connections. The following is a summary of
the seawater system installation:
The seawater system should be in-
5. Pull the insulation back up over the mylar to the ring
and tape this joint.
6. Remove excess ducting and use the same connection
method at the supply air grille.
All ducting should:
• Be appropriately sized for each application.
• Run as smoothly and taut as possible.
• Have as few bends or loops as possible.
• Be securely fastened to prevent sagging during boat
operation.
• Have all excess ducting lengths trimmed off.
• Not be flattened or kinked.
• Insulated when located in high heat load areas (hull
side, mechanical compartments, etc.).
• Be properly protected against potential damage
when routed through open areas.
Seawater Pump and Plumbing
Several guidelines should be followed during the installation of the seawater system. Since the circulation pump
is centrifugal and not self-priming, it must be mounted so
that it is always at least one foot below the water line
regardless of which tack the vessel is on. Pump may be
mounted horizontally or vertically, however the discharge
must always be above the inlet. Pump head should be
rotated toward the direction of water flow.
seawater speed scoop intake as far below the water
Install the
1. Install the speed scoop thru-hull inlet as close to the
keel and as far below the water line as possible, facing
forward. Bed the scoop with a marine sealant designed for underwater use.
2. Install a bronze, full flow seacock on the speed scoop
thru-hull inlet.
3. Install a seawater strainer below the level of the pump
with access to filter.
4. Mount the pump above the strainer and at least one
foot below the waterline.
5. Connect the seacock and strainer with an uphill run of
reinforced marine grade hose.
6. Connect the discharge from the pump uphill to the
bottom inlet of the a/c unit’s condenser coil with 5/8"
hose. Connect the discharge from the condenser coil
to the overboard discharge thru-hull fitting with 5/8"
hose.
7. Avoid loops, high spots or the use of 90° elbows with
seawater hose (each 90° elbow is equivalent to 2.5' of
hose and a 90° elbow on the pump outlet is equivalent
to 20' of hose).
8. Double clamp all hose connections with stainless steel
clamps, reversing the clamps.
9. Use teflon tape on all threaded connections.
Connect all metallic parts in contact with seawater
10.
to the vessel’s bonding system including the
speed scoop inlet, strainer, pump and the air
conditioner. Failure to do so will void warranty.
L-2254 Installation
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Electrical Connections, Grounding
and Bonding
All a/c units have a terminal strip mounted inside the
electric box. The terminal strip is labeled for proper
connections of the electrical supply, ground wires and
pump circuits. A wiring diagram is provided in the
electrical box and in this manual. The wiring diagram in
the electrical box supersedes the one in this manual and
ABYC standards. The correct size circuit breaker should
be used to protect the system as specified on the a/c
unit’s data plate label. A minimum of 12 AWG boat cable
should be used to supply power to the a/c unit and the
seawater pump. All connections shall be made with ring
or captive fork terminals. Turn off a/c power supply
circuit breaker before opening electric box. See
Figures 9 and 10.
Each a/c unit installed requires its own dedicated circuit
breaker. If there is only one a/c unit installed, the
seawater pump does not require a circuit breaker; the
wiring from the seawater pump is connected to the
terminal strip in the electric box. If two or more a/c units
use the same seawater pump, the pump wires will be
connected to a pump relay panel (PRP) which in turn
has its own dedicated circuit breaker sized for the pump
(20 amp max). Please see the wiring diagram furnished
with the PRP (NOTE: PRP triac must have its mounting
screw installed in order to dissipate heat). Electrical
connections in the bilge and/or below the waterline
should use heat shrink type butt splices.
ABYC standards are available from:
American Boat and Yacht Council
3069 Solomons Island Rd.
Edgewater, MD 21036
Telephone: (410) 956-1050
The a/c unit must be connected to the ship’s bonding
system to prevent corrosion due to stray electrical
current or voltage. All pumps, metallic valves and
fittings in the seawater circuit that are isolated from the
a/c unit by PVC or rubber hoses must be individually
bonded to the vessels bonding system also. This will
help eliminate any possibility of corrosion due to stray
current or voltage.
FAILURE TO PROPERLY GROUND AND BOND THE
SYSTEM WILL VOID WARRANTY!
3 Phase Notice
It is extremely important to insure that wiring and phase
sequencing of a three phase power source is correct.
Marine wiring standards call for power source phases L1,
L2, and L3 to be color-coded BLACK, WHITE, and RED,
respectively. These must be connected to the unit with
the proper sequence, otherwise, it will not operate
properly. If the wiring sequence is incorrect, the unit’s
compressor (Scroll type only) and pump (if applicable)
will run in the reverse direction at a significantly increased noise level.
Field wiring must comply with ABYC electrical codes.
Power to the unit must be within the operating voltage
range indicated on the data plate. Properly sized fuses
or HACR circuit breakers must be installed for branch
circuit protection. See data plate for maximum fuse/circuit
breaker size (mfs) and minimum circuit ampacity (mca).
All units must be effectively grounded to minimize the
hazard of electrical shock and personal injury.
The following are to be observed:
1. AC (alternating current) grounding (green wire) must
be provided with the AC power conductors and
connected to the ground terminal (marked “GRND”) at
the AC power input terminal block of the unit(s), per
ABYC standard E-8, or equivalent.
2. Connections between the vessel’s AC system grounding conductor (green wire) and the vessel’s DC (Direct
Current) negative or bonding system should be made
as part of the vessel’s wiring, per ABYC standard E-9,
or equivalent.
3. When servicing or replacing existing equipment that
contains a chassis-mounted ground stud, the service
person or installer must check the vessel’s wiring for
the existence of the connection required in item 2
above.
Manual Control Panel (MCP)
Installation
The MCP should be located within cap tube length of the
a/c unit. The 3 knob MCP is configured either vertically
(shown) or horizontally. The cut out size is 2.5" by 7.0",
see MCP (Figure 6) for orientation. Once the cut out is
made, carefully uncoil the copper cap tube with return air
sensor (copper bulb) and route the control wires and cap
tube through the hole and back to the a/c unit
caution not to kink the cap tube
sensor into the clips provided with the Vector Compact
unit. If the return air sensor cannot be mounted on the
evaporator coil, mount it behind the return air grille. The
sensor must be mounted in the return air stream. Make
electrical connections according to the wiring diagram
found in the electric box and/or in this manual. See
Figure 9.
. Mount the return air
using
L-2254 Installation
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Installation Checklist
(Review prior to installation)
Note: Refer to the Elite and Passport I/O manuals
for installation and operation of those digital
controls.
Seawater Cooling System
❑ Speed scoop located as far below the water line and
as close to the keel as possible
Electrical
❑ The wiring diagram is located in the electrical box. If
that diagram is damaged or if you need a copy, please
call Dometic with the unit part number, serial number,
and wiring diagram number, all of which are located on
the unit data plate.
❑ All butt connections on pumps wire tightly crimped and
heat shrunk
❑ AC power source installed and grounded/bonded in
accordance with ABYC standards
❑ Shut off valve (sea cock) and speed scoop properly
sealed and tight
❑ Seawater pump is at least one foot below water line
and securely mounted
❑ Strainer mounted below pump with access to filter
❑ Double/reversed stainless steel hose clamps on all
hose connections
❑ Teflon tape on all threaded connections
❑ Hose runs uphill from speed scoop and sea cock to
strainer, pump and a/c unit, then downhill (if possible)
from a/c unit to overboard discharge
❑ Water flowing freely from overboard discharge while
pump is running
❑ Pump relay panel, if used, must have its own circuit
breaker sized for the pump (20 amp max)
❑ All metal fittings should be bonded
Mounting
❑ Not in engine room or bilge areas, must be sealed
away from exhaust or fumes
❑ Control wires connected to terminal strip with captive
fork or ring terminals
❑ Circuit breakers sized according to specifications on
the data plate label
❑ Digital display cable is connected at both ends
❑ Pump Relay Panel (if used) has a dedicated circuit
breaker sized for the pump but not to exceed 20 amps
maximum.
Grilles and Ducting
❑ Supply air grille mounted as high as possible
❑ Return air grille mounted as low and as close to the
a/c unit as possible
❑ Return air grille mounted away from bilge vapors or
exhaust fumes
❑ Ducting is pulled taut, straight, smooth and properly
connected with no excess
❑ Proper spacing allowed around unit
❑ Attached to solid level platform with hold down clips
provided
❑ Condensate drain routed aft and down hill to a sealed
sump (not bilge)
❑ Blower rotated toward supply air grille
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OPERATION
Mechanical Control Panel
(MCP) Operation
1. Ensure seawater intake ball valve (sea cock) is open.
2. Turn SYSTEM SWITCH control knob to OFF.
3. Turn on AC circuit breaker. If the seawater pump has
its own circuit breaker, turn that on too. Or, if the pump
is connected to a Pump Relay Panel (PRP), then turn
on that circuit breaker also.
4. Turn the SYSTEM SWITCH control knob to START;
this energizes the fan and seawater pump. Turn
THERMOSTAT control knob to the coolest position by
rotating fully clockwise. If system has reverse cycle,
turn knob counter-clockwise for heat.
5. Check for a steady solid stream of seawater from the
overboard discharge.
6. Turn FAN SPEED control knob clockwise to highest
setting for cooling or counter-clockwise for heating.
7. Verify that the fan is running and that there is steady
airflow out of the supply air grille.
8. Turn the SYSTEM SWITCH to RUN; this will start the
compressor. The indicator light on the control will
illuminate.
Quick Start Operations Checklist
❑ Ensure seawater intake ball valve (sea cock) is open.
❑ Turn on the a/c circuit breaker. If the seawater pump
has its own circuit breaker, turn that on.
❑ Turn the system on.
❑ Set the desired cabin temperature (set point).
❑ Check for a steady solid stream of water from the
overboard discharge.
❑ Verify that there is steady airflow out of the supply air
grille.
❑ If the unit does not appear to be operating properly,
refer to troubleshooting guide lines.
Note: Do not turn the unit off and immediately turn it
back on. Allow at least 30 seconds for refrigerant
pressure equalization.
9. To set the thermostat, allow sufficient time for the unit
to cool/heat the area to the desired temperature. When
the area is sufficiently cooled/heated, turn the thermostat knob slowly toward the center position until it
clicks once (the indicator light will turn off). The
thermostat is now set to maintain a constant temperature. While heating, if the ambient temperature is less
than 50°F, set the FAN SPEED control knob to low for
five to ten minutes until the unit begins to heat well,
then increase the fan speed for more heat output and
to prevent the system cycling on high pressure.
The thermostat on the MCP control panel serves to cycle
the compressor on and off and provide an automatic
changeover from cooling to heating (reverse cycle only)
with a 3.5° differential. Rotating the thermostat to the left
after it has been set for cooling will cause the unit to
heat. If you rotate the thermostat to the right, the unit will
cool. If the thermostat is left stationary after being set,
the unit will cycle from cooling to neutral, or heating to
neutral depending on the requirement.
Reverse cycle units have a reversing valve that must be
energized periodically to keep the internal parts moving
freely. To accomplish this, switch the A/C into HEAT for a
few seconds once a month.
Note: Do not turn the unit off and immediately turn it
back on. Wait at least 30 seconds.
L-2254 Operation
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