Mars Comfort-aire Century MCD18B1A Quick start guide

OWNER’S & INSTALLATION MANUAL
Split Horizontal-Vertical
Duct Air Conditioner
Indoor Unit
Models
MCD18B1A MCD24B1A
MCD30C1A MCD36C1A
MCD48C1A MCD60D1A
517.787.2100 • www.marsdelivers.com
Owner’s Manual &
Installation Manual
IMPORTANT NOTE:
Read this manual carefully before installing
or operating your new air conditioning
unit. Make sure to save this manual for
future reference.
Split Horizontal-Vertical Duct Air Conditioner Indoor Unit
Owner’s Manual &
Installation Manual
IMPORTANT NOTE:
Read this manual carefully before installing
or operating your new air conditioning
unit. Make sure to save this manual for
future reference.
Split Horizontal-Vertical Duct Air Conditioner Indoor Unit

Owner’s and Installation Manual - MCD Coil Series
2
Table of Contents
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SAFETY PRECAUTIONS
INTRODUCTION
INSTALLATION
1. INSPECT EQUIPMENT
2. INSTALLATION OF EVAPORATOR COILS
3. REFRIGERANT LINE CONNE
4. CONNECT REFRIGERA
5. REFRIGERANT METERING DEVICE ......................................................................................................................................10
6. CONDENSATE DRAIN LINECONNECTION
7. WASTE LINE CONNECTION
CARE AND MAINTENANCE

Owner’s and Installation Manual - MCD Coil Series
3
Read Safety Precautions Before Operation and Installation
The seriousness of potential damage or injuries is classified as either a WARNING or CAUTION.
Incorrect installation due to ignoring instructions can cause serious damage or injury.
WARNINGS FOR PRODUCT USE
•
If an abnormal situation arises (like a burning smell), immediately turn o the unit and disconnect
the power. Call your dealer for instructions to avoid electric shock, re or injury.
•
Do not
insert fingers, rods or other objects into the air inlet or outlet. This may cause injury, since
the fan may be rotating at high speeds.
•
Do not
use flammable sprays such as hair spray, lacquer or paint near the unit. This may cause
fire or combustion.
•
Do not
operate the air conditioner in places near or around combustible gases. Emitted gas may
collect around the unit and cause explosion.
•
Do not
•
•
Do not
expose your body directly to cool air for a prolonged period of time.
•
•
•
If the air conditioner is used together with burners or other heating devices, thoroughly ventilate
the room to avoid oxygen deficiency.
SAFETY PRECAUTIONS
Do not
allow children to play with the air conditioner. Children must be supervised around the
unit at all times.
operate your air conditioner in a wet room such as a bathroom or laundry room. Too
much exposure to water can cause electrical components to short circuit.
In certain functional environments, such as kitchens, server rooms, etc., the use of specially
designed air-conditioning units is highly recommended.
Improper installation, adjustment, alteration, service or maintenance can cause property damage,
personal injury or loss of life. Installation and service must be performed by a licensed professional
HVAC installer or equivalent, service agency, or the gas supplier.
WARNING
This symbol indicates the possibility
of personnel injury or loss of life.
CAUTION
This symbol indicates the possibility of
property damage or serious consequences.
Safety
Precautions
 Page 4

Owner’s and Installation Manual - MCD Coil Series
4
CAUTION
• Turn o the air conditioner and disconnect the power if you are not going to use it for a long time.
• Turn o and unplug the unit during storms.
• Make sure that water condensation can drain unhindered from the unit.
•Do not operate the air conditioner with wet hands. This may cause electric shock.
•Do not use device for any other purpose than its intended use.
•Do not climb onto or place objects on top of the outdoor unit.
•
•
Do not allow the air conditioner to operate for long periods of time with doors or windows open,
or if the humidity is very high.
ELECTRICAL WARNINGS
• Only use the specified power cord. If the power cord is damaged, it must be replaced by the
manufacturer , its service agent or similarly qualied persons in order to avoid a hazard.
• Keep power plug clean. Remove any dust or grime that accumulates on or around the plug. Dirty
plugs can cause re or electric shock.
•
•
•
•
•
•
•
Do not pull power cord to unplug unit. Hold the plug firmly and pull it from the outlet. Pulling
directly on the cord can damage it, which can lead to fire or electric shock.
Do not modify the length of the power supply cord or use an extension cord to power the unit.
Do not share the electrical outlet with other appliances. Improper or insucient power supply
can cause re or electrical shock.
If connecting power to xed wiring, an all-pole disconnection device which has at least 3mm
clearances in all poles, and have a leakage current that may exceed 10mA, the residual current
device(RCD) having a rated residual operating current not exceeding 30mA, and disconnection
must be incorporated in the xed wiring in accordance with the wiring rules.
For all electrical work, follow all local and national wiring standards, regulations, and the
Installation Manual. Connect cables tightly, and clamp them securely to prevent external forces
from damaging the terminal. Improper electrical connections can overheat and cause re, and may
also cause shock.
All electrical connections must be made according to the Electrical Connection
Diagram located on the panels of the indoor and outdoor units.
All wiring must be properly arranged to ensure that the control board cover can close properly. If
the control board cover is not closed properly, it can lead to corrosion and cause the connection
points on the terminal to heat up, catch re, or cause electrical shock.
The product must be properly grounded at the time of installation, or electrical shock may occur.
TAKE NOTE OF FUSE SPECIFICATIONS
The air conditioner’s circuit board (PCB) is designed with a fuse to provide overcurrent protection.
The specifications of the fuse are printed on the circuit board ,examples of such are T5A/250VAC and
T10A/250VAC.
As with any mechanical equipment, contact with sharp sheet metal edges can result in personal
injury. Take care while handling this equipment and wear gloves and protective clothing.
Safety
Precautions
 Page 5
•Do not
clean the air conditioner with combustible cleaning agents. Combustible cleaning agents
can cause re or deformation.
CLEANING AND MAINTENANCE WARNINGS
• Turn o the device and disconnect the power before cleaning. Failure to do so can cause electrical
shock.
•Do not
clean the air conditioner with excessive amounts of water.

Owner’s and Installation Manual - MCD Coil Series
5
Safety
Precautions
 Page 6
WARNINGS FOR PRODUCT INSTALLATION
1. Installation must be performed by an authorized dealer or specialist. Defective installation can
Excessive Weight Hazard - Use two or more people when moving and installing the unit. Failure
to do so can result in back or other type of injury.
T
ake precautions to ensure Aluminum tubes do not come in direct contact or allow for
condensate run o with a dissimilar metal. Dissimilar metals can cause galvanic corrosion
and possible premature failure.
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care and wear appropriate
protective clothing and gloves when handling parts.
cause water leakage, electrical shock, or re.
2. Installation must be performed according to the installation instructions. Improper installation
can cause water leakage, electrical shock, or re.
(In North America,installation must be performed in accordance with the requirement of NEC
and CEC by authorized personnel only.)
3.
Contact an authorized service technician for repair or maintenance of this unit. This appliance
shall be installed in accordance with national wiring regulations.
4.
Only use the included accessories, parts, and specied parts for installation. Using non-standard
parts can cause water leakage, electrical shock, re, and can cause the unit to fail.
5.
6.
Install the unit in a rm location that can support the unit’s weight. If the chosen location cannot
support the unit’s weight, or the installation is not done properly, the unit may drop and cause
serious injury and damage.
7.
8.
9.
10.
11.
12.
13.
14.
Do not turn on the power until all work has been completed.
When moving or relocating the air conditioner, consult experienced service technicians for
disconnection and reinstallation of the unit.
Follow all safety codes. Wear safety glasses, protective clothing, and work gloves. Use quenching
cloth for brazing operations. Have re extinguisher available.
For units that have an auxiliary electric heater, do not install the unit within 1 meter (3 feet) of
any combustible materials.
Do not install the unit in a location that may be exposed to combustible gas leaks. If combustible
gas accumulates around the unit, it may cause re.
Install drainage piping according to the instructions in this manual. Improper drainage may
cause water damage to your home and property.

Owner’s and Installation Manual - MCD Coil Series
Use this instruction manual to install indoor coil on multi position furnaces. The
coil is enclosed in a casing.
Introduction
 Page 7
INTRODUCTION
Typical Coil Installation on Furnace
Supply Return
Return Supply
Evaporator
Coil
Horizontal Left Furnace Installation
Horizontal Right Furnace Installation
Evaporator
Coil
Return
Return
Supply
Supply
Downow
Furnace
Installation
Upow
Furnace
Installation

Owner’s and Installation Manual - MCD Coil Series
7
INSTALLATION
INSTALLATION OF EVAPORATOR COILS
Upflow coil installation
The cased coil is designed to t furnaces of the
same width.
1. Set coil in place on upow furnace discharge
air opening.
2. Ensure coil is level for proper condensate
drainage. Do not tip coil toward condensate
drain. Coil casing need not be fastened or
screwed to furnace.
3. When installing wider coil on narrow furnace,
create eld fabricated adapter.
NOTE: On upow installations where the indoor
coil is placed in an unconditioned space, a 6”
wide piece of insulation should be applied and
wrapped around the outside of coil casing and
supply duct contact point.
NOTE: Consult the furnace installation instructions
for any special requirements when installing the
coil to the furnace.
Installation
 Page 8
Adapter(s) Installation When Coil Overhangs Furnace
4"minimum
4"minimum
Furnace
Furnace
Coil
Coil
Airow Ductwork
Airow
Ductwork
Horizontal Right & Left Installation
Airow
Airow
Ductwork
Ductwork
4"minimum
Coil
Furnace
4"minimum
Furnace
Coil
Vertical Upow & Downfolw Installation

Owner’s and Installation Manual - MCD Coil Series
8
 Page 9
Downflow Coil Installation
IMPORTANT: Installing “A" coils rotated 90
degrees from the front of the furnace in
downow applications can cause water blow
o or coil freeze up. This is due to the
concentration of air on one coil slab or lack of
air on the opposite coil slab. If the airow is
high due to ductwork or other causes, and
there is a chance for water blow o, it is
recommended that a 4-in. minimum
eld-supplied adapter be placed between
the coil and the furnace to allow the air to
distribute evenly to both coil slabs.
Horizontal Coil Installation
The unit can be installed on a work platform,
secured to roof truss in attic, suspended from
hangers on oor joists in crawl space, or installed
on blocks. It is designed to allow airow in either
direction, to mate with horizontal-left or
horizontal-right furnace installations. Ensure
coil cabinet is level side to side and front to back.
It is allowable to add up to 1/2-in. additional
slope over length and depth of coil cabinet in
the direction of drain pan connection.
Horizontal Right Installation
1. Use eld fabricated attachment plates to
secure coil to furnace.
2. Use self-tapping screws to mount attachment
plates to coil casing.
3. Connect furnace snugly against coil casing.
4. Use self-tapping screws to attach furnace.
5. Seal joint between coil casing and furnace to
create an air tight seal using locally approved
materials.
6. Use cork tape to create air seal between the
undersides of the pan extension and front of
the vertical drain pan as shown below.
8. If coil is wider than furnace, use 4-in minimum
transition and self tapping screws to attach
furnace.
7. Install included condensate pan extension
and two corner screws as shown below.
4. Set cased coil on supply duct opening.
5. Place eld fabricated 4-in. minimum adapter
on coil casing. Adapter should be tapered to
t coil/furnace combination when one of
them is larger than the other.
6. Set furnace on adapter.
NOTE: In downow installation with a 4-way
multipoise furnace, break o perforated duct
anges on furnace. See furnace installation
instructions.
Downow Installation with Coil Rotated 90° Horizontal Left Installation
1. Unbend the 4 tabs at the right side of the
casing.
2. Connect furnace snugly against coil casing.
3. Use self-tapping screws to attach furnace.
4. Seal joint between coil casing and furnace to
create air tight seal using locally approved
materials.
5. If coil is wider than furnace, use 4-in. Minimum
transition and self tapping screws to attach
furnace.
Installation
4"

Owner’s and Installation Manual - MCD Coil Series
9
 Page 10
CONNECT REFRIGERANT, LIQUID,
and SUCTION LINES
WARNING
• Failure to follow this warning could result
in personal injury. Wear eye protection.
•
Coil is factory charged with 15 psi nitrogen.
The coil is under pressure and TXV screen is
in place behind liquid line plug. DO NOT
remove liquid line plug rst, always remove
the suction line plug rst to depressurize
the coil.
CAUTION
Failure to follow this caution may result in
property damage.
Take precautions to ensure Aluminum tubes
do not come in direct contact or allow for
condensate run o with a dissimilar metal.
Dissimilar metals can cause galvanic
corrosion and possible premature failure.
NOTE: Factory nitrogen charge may escape past
rubber plugs during storage. This does not
indicate a leaking coil nor warrant return of the
coil.
Size and install refrigerant lines according to
information provided with outdoor unit. Coil
connection tube sizes are shown in Table .
Route refrigerant lines to the coil in a manner
that will not obstruct service access to the unit
or removal of the lter.
Do not use damaged, dirty, or contaminated
tubing because it may plug refrigerant
ow-control device. ALWAYS evacuate the coil
and eld-supplied tubing before opening
outdoor unit service valves.
For matched and mismatched systems, use line
sizes recommended in outdoor unit Installation
Instructions.
REFRIGERANT LINE CONNECTIONS
The coil can be connected to outdoor units
using eld-supplied tubing of refrigerant
grade.
Always evacuate tubing and reclaim refrigerant
when making connections or aring tubing.
Leak check connections before insulating entire
suction line.
See Table for coil connection tube size.
1. Remove cabinet access door.
2. Remove rubber plugs, suction plug then liquid
plug, from coil stubs using a pulling and
twisting motion. Hold coil stubs steady to avoid
bending or distorting.
3. Remove tubing plate with rubber grommets
and slide plate with grommets onto the
refrigerant lines (eld line-set), away from
braze joints.
4. Fit refrigerant lines into coil stubs. Wrap a heat
sinking material such as a wet cloth behind
braze joints.
5. Wrap TXV and nearby tubing with a heat-sinking
material such as a wet cloth.
6. Use 1/2 psig Nitrogen purge in the suction and
out the the liquid line.
7. Braze using a Sil-Fos or Phos-copper alloy. Do
not use soft solder.

Owner’s and Installation Manual - MCD Coil Series
10
 Page 11
Installation
REFRIGERANT METERING DEVICE
CONDENSATE DRAIN LINE
CONNECTION
WARNING
•
Failure to follow this warning could result
in personal injury or death.
Provide trap with air gap in drain line when
connecting to waste (sewer) line。
CAUTION
Failure to follow this caution may result in
product damage.
To avoid valve damage to the refrigerant
control device while brazing, valves must be
wrapped with a heat-sinking material such
as a wet cloth.
CAUTION
Failure to follow this caution may result in
property damage.
When installing over a nished ceiling and/
or living area, install a eld-fabricated
secondary condensate pan under the entire
unit.
CAUTION
Failure to follow this caution may result in
product damage.
DO NOT BURY MORE THAN 36 IN. OF
REFRIGERANT TUBING IN GROUND. If any
section of tubing is buried, there must be
a 6 in. vertical rise to the valve connections
on the outdoor unit. If more than the
recommended length is buried, refrigerant
may migrate to cooler buried section during
extended periods of unit shutdown, causing
refrigerant slugging and possible compressor
damage at start-up
These Coils have a factory installed hard shut-o
TXV designed only for use with R-410A refrigerant.
Use only with outdoor units designed for R-410A.
NOTE: ALL TXV’S HAVE PRESET SUPERHEAT
SETTINGS AND ARE FIELD NON-ADJUSTABLE.
8. After brazing, allow joints to cool. Carefully
remove TXV bulb insulation and verify that
the TXV bulb is securely fastened with hose
clamp. Tighten screw a half-turn past hand
tight with TXV bulb placed in the indentation
with full contact with the vapor line tube.
Re-wrap TXV bulb with insulation.
9. Leak check connections before insulating
entire suction line.
10. Slide tubing plate with rubber grommets
over joints. Position tubing at center of each
grommet to ensure an air seal around the
tube. Reinstall cabinet door.
The coil is designed to dispose of accumulated
water through built-in condensate drain ttings.
It is recommended that PVC ttings be used on
the condensate pan. Do not over-tighten. Finger
tighten plus 1-1/2 turns. Be sure to install plastic
plug in unused condensate drain tting. Two
3/4 inch female threaded pipe connections are
provided in each coil condensate pan.
A trap is not necessary on the condensate line if
on the supply air side of furnace. Consult local
codes for additional restrictions or precautions.
If local codes require a trap then the following
guidelines are suggested to assure proper
drainage. Install a trap in condensate line of
coil as close to the coil as possible. Make trap
at least 3 inches (76 mm) deep and no higher
than the bottom of unit condensate drain
opening . Pitch condensate line 1 inch (25.4 mm)
for every 10 ft. of length to an open drain or
sump. Make sure that the outlet of each trap is
below its connection to condensate pan to
prevent condensate from overowing the drain
pan. Prime all traps, test for leaks, and insulate
traps and lines if located above a living area.