Suntherm MSVT Series User manual

MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 1
Multi-Position DX and Chilled Water Cooling With Hot Water Heating
Models: MSVT Series With Single-Stage Cooling/Heat Pump Airow
MSVE Series with Single and 2-Stage Cooling/Heat Pump Air-Flow
INSTALLATION MANUAL
7 – Line Voltage Wiring............................................................................................16
8 – Thermostat Wiring and Connections ..........................................................18
9 – Blower Performance..........................................................................................21
10 – Blower Motor Speed Selection .....................................................................23
11 – Filling Heating System With Water and System Startup ......................24
12 – Wiring Diagrams................................................................................................ 25
1 – General...........................................................................................................1
2 – Safety..............................................................................................................2
3 – Location, Clearances and Return Air Requirements......................6
4 – Air Handler Orientation and Supply Air Duct Installation ...........7
5 – Air Handler Installation ............................................................................8
6 – Refrigerant/Condensate Piping, TXV, Hot/Chilled Water Piping.....8
LIST OF SECTIONS
LIST OF FIGURES
LIST OF TABLES
SECTION 1: GENERAL
1 – Air Handler Dimensions...........................................................................5
2 – Clearance – Access for Service...............................................................6
3 – Closet Clearances .......................................................................................6
4 – Air Filter Base Accessory for 1”or 2” Air Filters .................................7
5 – Indoor Coil Below Outdoor Unit Piping.............................................8
6 – Typical TXV Connections..........................................................................9
7 – TXV Sensing Bulb Placement ............................................................... 9
8 – Typical Condensate Trap....................................................................... 10
9 – Hydronic Control Box Power Connection Locations .................. 16
10 – Component Locations – Hydronic Heat - No Pump................... 17
11 – Component Locations – Hydronic Heat With Pump.................. 17
12 – Hydronic Heat w/1-Stage Cooling Low Voltage Wiring ............ 19
13 – Hydronic Heat w/1-Stage Heat Pump Low Voltage Wiring.........19
14 – ECM Motor Control Plug Pin Positions.................................................23
15 – ECM Control Board Layout........................................................................23
16 – Constant Torque Motor Terminals..........................................................24
17 – Wiring Diagram: MSVE 18 - 36; ECM Mtr; No Choke; No Pump..25
18 – Wiring Diagram: MSVE 18 - 36; ECM Mtr; w/Pump; No Choke ...25
19 – Wiring Diagram: MSVE 37 - 72; ECM Mtr; w/Choke & Pump .......26
20 – Wiring Diagram: MSVE 37 - 72; ECM Mtr; w/Choke; No Pump ...26
21 – Wiring Diagram: MSVT 18 - 36 / C.T. Mtr; w/Pump; No Choke....27
22 – Wiring Diagram: MSVT 18 - 36 / C.T. Mtr; No Pump; No Choke..27
23 – Wiring Diagram: MSVT 37 - 60; C.T. Motor; w/Choke & Pump....28
24 – Wiring Diagram: MSVT 37 - 60; C.T. Motor; w/Choke/No Pump 28
1 – Hydronic Air Handler Model Specications......................................3
2 – Air Handler Model Number Nomenclature.......................................4
3 – Air Handler Dimensional Data...............................................................5
4 – Clearance to Combustibles and For Service Access.......................6
5 – Chilled Water“A” Coil Cooling Cap. 80/67°F EAT 45°F EWT....... 11
6 – Heating Capacity For Water“A” Coil @ 120°F and 140°F ............ 11
7 – Heating Capacity For Water“A” Coil @ 160°F and 180°F ............ 11
8 – Htg Cap Boiler Loop No Pump 65°F EAT 180 °F EAT 20°F t.... 12
9 – Htg Cap Boiler Loop No Pump 65°F EAT 180 °F EAT 20°F t.... 12
10 – Htg Cap Boiler Loop No Pump 65°F EAT 180 °F EAT 20°F t.... 13
11 – Htg Cap Factory Pump 65°F EAT @ Stated EWT 1.5, 2 Ton ....... 14
12 – Htg Cap Factory Pump 65°F EAT @ Stated EWT 2, 2.5, 3 Ton... 14
13 – Htg Cap Factory Pump 65°F EAT @ Stated EWT 3.0 – 6.0 Ton . 15
14 – Wiring Requirements–115V Hydronic 18-36 KBTU Models..... 16
15 – Wiring Requirements–115V Hydronic 37-72 KBTU Models..... 17
16 – Low Voltage Wire Gauge and Maximum Lengths....................... 18
17 – Typical Heat/Cool T-stat Wire Colors & LowVoltage Connections . 19
18 – Typical Ht PumpT-stat Wire Colors & Low Voltage Connections. 19
19 – MSVT Blower Performance Chart – Constant Torque Motors. 21
20 – MSVE Blower Performance Chart – ECM Motors......................... 22
21 – ECM Motor Control Connector Terminals ...................................... 23
22 – Constant Torque Motor Terminal Connections............................ 24
SAVE THIS MANUAL FOR FUTURE REFERENCE
1. Air handler is rated for 208/240 VAC at 60 Hertz.
2. Air handler size varies by model.
3. Air handler is designed for A/C or heat pump operation.
4. Air handler is designed for upow, downow and
horizontal applications.
5. Air handler must not be operated with the access
panels removed.
6. Air handler is listed by ETL in the United States and Canada.
7. This air handler is for use at elevations of 10,000 ft (3,048m)
or less.
8. This appliance is not to be used by persons (including children)
with reduced physical, sensory or mental capabilities, or lack
of experience and knowledge, unless they have been given
supervision or instruction concerning use of this appliance by
a person responsible for their safety. Children must not be
allowed to play with this appliance.
The following list includes important facts and information regarding the air handler models covered in this manual.
9700771

MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 2
This is a safety alert symbol. When you see this symbol on
labels or in manuals, be alert to the potential for personal injury.
Understand and pay particular attention to the signal words
DANGER, WARNING, or CAUTION.
DANGER: Indicates an imminently hazardous situation, which
if not avoided, will result in death or serious injury.
WARNING:Indicates a potentially hazardous situation, which
if not avoided, could result in death or serious injury.
CAUTION: Indicates a potentially hazardous situation, which
if not avoided, may result in minor or moderate injury. It is
also used to alert against unsafe practices and hazards involving
property damage.
Improper installation may create a condition where the
operation of the product could cause personal injury or
property damage.
Improper installation, adjustment, alteration, service or
maintenance can cause injury or property damage. Refer
to this manual for assistance; or for additional information
consult a qualied contractor, installer, or service agency.
FIRE OR ELECTRICAL HAZARD
Failure to follow the safety warnings exactly could result
in serious injury, death, or property damage. A re or
electrical hazard may result causing property damage,
personal injury or loss of life.
This air handler must be installed in strict compliance with
the installation instructions and any applicable local, state,
and national codes including, but not limited to, building,
electrical, and mechanical codes.
MS Series Multi-Position Air Handler
Safety Requirements
This air handler should be installed in accordance with all national
and local building/safety codes and requirements, local plumbing
or waste water codes, and other applicable codes. In the absence
of local codes, install in accordance with the following codes.
• Standard for the Installation of Air Conditioning and
Ventilating Systems (NFPA 90A)
• Standard for the Installation of Warm Air heating and Air
Conditioning Systems (NFPA 90B)
• National Electrical Code (NFPA 70)
• Canadian Electrical Code, Part I (CSA C22.2) or ANSI/NFPA
No. 70
• All local codes (State, City, and Township)
NOTE: All applicable codes take precedence over any
recommendation made in these instructions.
SunTherm assumes no responsibility for air handlers installed in
violation of any code or regulation.
1. Refer to the air handler rating plate for the air handler model
number and then refer to Figure 1 for return air plenum
dimensions that apply to that model number. The plenum
must be installed according to the above listed codes or the
instructions in this manual.
2. These models are not ETL listed or approved for installation
into a Manufactured (Mobile) Home.
3. Provide clearances from combustible materials as listed under
Clearances to Combustibles.
4. Provide adequate clearances for service access to the control
box, indoor coil, hot water coil and blower.
5. Failure to carefully read and follow all instructions in this
manual can result in malfunction of the air handler, death,
personal injury, and/or property damage.
6. The air handler must be installed so the electrical components
are protected from water.
7. Installing and servicing heating/cooling equipment can be
hazardous due to electrical components.
8. Only trained and qualied personnel should install repair or
service heating/cooling equipment. Untrained service .
Untrained service personnel should only perform
basic maintenance functions such as cleaning of exterior
surfaces and replacing the air lters. Observe all precautions
in the manuals and on the attached labels when servicing this
air handler. These instructions cover minimum requirements
and conform to existing national standards and safety codes.
9. In some cases, these instructions exceed certain local codes
and ordinances, especially those who have not kept up with
changing home and/or HUD construction practices.
10. These instructions are to be followed and are the minimum
requirement for a safe installation.
11. The capacity of the air handler should be based on an
acceptable heat loss calculation for the structure such as ACCA
Manual J or other approved methods.
The Clean Air Act of 1990 bans the intentional
venting of refrigerant (CFC’s and HFC’s) as of July
1, 1992. Approved methods of reclaiming must be
followed. Fines and/or incarceration may be levied for
non-compliance.
SECTION 2: SAFETY

MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 3
GENERAL INFORMATION
This air handler provides the exibility for installation in an
upow or horizontal application and may be used with or
without hot water heat. The direct-drive variable speed ECM
or 5-speed constant torque motors provide a wide selection of
air-ow volume to match any application. The air handler can
be positioned for bottom air return in the upow position or
air return through the end of the air handler in the horizontal
position.
NOTE: Refer to the instructions in this manual for instructions on
the proper conversion from the as shipped right-to-left horizontal
conguration to the left-to-right horizontal conguration.
Available Blower Motors
1. Variable Speed ECM
2. 5-Speed Constant Torque
INSPECTION
As soon as the air handler is received, it should be inspected for
possible damage during transit. If damage is evident, the extent
of the damage should be noted on the carrier’s freight bill. A
separate request for inspection by the carrier’s agent should
be made in writing. Before installing the air handler, check the
cabinet for screws or bolts which may have loosened in transit.
There are no shipping or spacer brackets which need to be
removed before startup.
See local Distributor for more information. Mortex Products, Inc.
assumes no liability for freight damage.
Check to be sure all accessories that are required for the
installation are available. Installation of these accessories should
be completed before the air handler is set in place and connected
to wiring, ductwork, and piping.
Hot water from a boiler used to satisfy heating
requirements can be heated to temperatures of 180°F.
Parts containing hot water can scald very quickly.
Use extreme caution when servicing or performing
maintenance on any parts containing hot water.
ALWAYS SHUT OFF ELECTRICITY AT THE DISCONNECT
SWITCH OR TURN OFF THE CIRCUIT BREAKERS IN THE MAIN
ELECTRICAL ENTRANCE BEFORE PREFORMING ANY SERVICE
ON THE AIR HANDLER.
12. Conrm the power supply meets the electrical characteristics
listed on the air handler rating plate. All models must be
connected to a nominal 115 VAC, 1 Phase, 60-Hertz power
supply. DO NOT CONNECT THIS AIR HANDLER TO A 50 HZ
POWER SUPPLY OR A VOLTAGE ABOVE 140 VOLTS.
13. The eld ground wire MUST BE securely fastened to the
ground lug terminal in the air handler control box.
Cooling Only & Cooling With Hydronic Heat
Models MS**18,24 MS**25,30,36 MSVE**37,42,48,60 MSVT37,42,48,60; MSVE72
Hort Water Coil (Rows) 2,3 2,3,4 2,3,4 2,3,4
Blower Size-Heat (D x W) 10 X 7 (MSVE)
10 X 8 (MSVT)
10 X 7 (MSVE)
10 X 8 (MSVT)
12 X 9 12 X 10
Unit Voltage 115V, 60 HZ, 1 PH
Max. External SP (Duct), In. W.C. 0.60
Thermostat Circuit 24 VAC, 60 Hz, 40VA
Table 1: Hydronic Air Handler Model Specications

MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 4
Table 2: Hydronic Air Handler Model Number Nomenclature
MODEL NUMBER NOMENCLATURE
MS VT 36 15 B 862T AA
I II III IV V VI VII
ISeries
MS = Multi-Position Single-Piece
II
Motor Type
VT = Variable Constant Torque
VE = Variable Speed ECM
III
Unit Size (Capacity in MBTUH)
12 through 24 - Small Cabinet
25 through 36 - Medium Cabinet
37 through 72 - Large Cabinet
OS = No Cooling Small Cabinet
OM = No Cooling Medium Cabinet
OL = No Cooling Large Cabinet
IV
Heating Conguration
00 = Cooling Only
2P = 2 Row Hot Water Coil With Pump
3P = 3 Row Hot Water Coil With Pump
4P = 4 Row Hot Water Coil With Pump
2N = 2 Row Hot Water Coil No Pump
3N = 3 Row Hot Water Coil No Pump
4N = 4 Row Hot Water Coil No Pump
VAir Handler Voltage
A = 115 Volts
VI
SUMMIT Indoor Coil Conguration
862T = DX Coil Geometry And Metering Device
8K2N = CW Coil Geometry, No Metering Device
VII Option Code
AA = Standard Factory Options

DIMENSIONAL DATA MULTI-POSITION AIR HANDLER HYDRONIC HEAT
Model A B C D E F G H J K L M N P R S T
MS**18, 24 17.50 43.00 21.00 15.63 12.50 13.50 11.00 6.75 16.75 14.00 11.00 10.75 2.00 1.50 5.00 16.10 20.20
MS**25, 30, 36 21.00 48.00 21.00 19.00 12.50 14.50 13.00 6.75 20.00 17.00 12.75 10.30 2.30 4.35 5.00 19.90 20.80
MS**37, 42, 48, 60, 72 24.50 58.88 21.75 22.25 14.25 19.75 17.25 6.75 26.00 23.00 16.75 14.35 2.30 4.35 4.50 23.50 20.70
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 5
Figure 1: Air Handler Dimensions
Table 3: Air Handler Dimensional Data

MODEL TOP (in) BACK (in) SIDES (in) FRONT OF FURNACE DUCT (in)
ALCOVE (in) CLOSET (in)
HYDRONIC 0 0 0 30 6 1
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 6
LOCATION
Access for servicing is an important factor in the location of any
appliance. Provide a minimum of 30 inches in front of the air
handler for access to the control box, indoor coil, water pump,
blower, and air lters. This access may be provided by a closet
door or by locating the air handler so that a wall or partition is not
less than 30 inches from the front access panel. The location for
the air handler is usually predetermined. Check with the owner
or user for installation plans. If location has not been decided,
consider the following in choosing a suitable location.
1. Select a location with adequate structural support, space
for service access, clearance for return and supply duct
connections.
2. Normal operating sound levels may be objectionable if the
air handler is placed directly over or under some rooms such as
bedrooms, study, etc.
3. If possible, locate the air handler so ducts are about the same
length to achieve even air distribution of supply and return air
to and from the living spaces.
4. Locate air handler where electrical supply wiring can be easily
routed to main electrical panel and where electrical wiring will
not be damaged.
5. Locate air handler where thermostat wiring can be easily routed
to the thermostat and where the wiring will not be damaged.
6. Locate air handler where refrigerant lines can be easily routed
from the indoor coil to the outdoor unit.
7. Locate the air handler where condensate lines can be easily
routed to the outside or an available drain. Route condensate
drain piping so it does not obstruct access to the air lter or
access panels.
8. When the indoor coil is installed in a draw-through application
such is the case with this air handler, it will create a negative
pressure situation in the condensate drain system. To prevent
condensate from being drawn into the air handlers and blower,
it is recommended to trap the primary (main) and secondary
(overow) drain line. Refer to CONDENSATE DRAIN SYSTEM and
Figure 7 in these instructions. If the secondary drain is not used,
it must be capped.
9. The exterior surface of cabinet will sweat when an air handler
is installed in a non-conditioned space such as an attic or
garage. The installer must provide protection such as full
size auxiliary drain pan for all air handlers installed in a non
conditioned space to prevent damage from condensation
runo. It is recommended that air handlers installed in non
conditioned spaces be insulated on the exterior of the entire
county or local codes for insulation requirement to assure the
installation complies with all codes.
CLEARANCES
This air handler is approved for 0 inches of clearance to
combustible material to any part of the air handler exterior
cabinet. Refer to Figure 2 and 3 and Table 4 for clearance to
combustibles and for service access clearances.
SECTION 3: LOCATION, CLEARANCES AND
RETURN AIR REQUIREMENTS
Figure 2: Clearance – Access for Service Figure 3: Closet Clearances
Table 4: Clearances to Combustibles and Service Access

MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 7
RETURN AIR REQUIREMENTS
For the air handler to work properly, a closet or alcove must have
a certain total free area opening for the return air.
For A/C and HP Air Handlers 1/3 HP Blower Motor On MSVE,
MSVT18 & 24
• Minimum 200 in© free area opening
• Use Return Grille or Coil Cabinet
For A/C and HP Air Handlers 1/2 HP Blower Motors On MSVE,
MSVT25, 30, & 36
• Minimum 250 in free area opening
• Use Return Grille, A/C Coil Cabinet, or any return grille
• with a minimum 250 in² free area opening.
For A/C and HP Air Handlers with Hydronic Heat use 1.0 HP
Blower Motor On MSVE/MSVT 37, 42, 48, & 60
• Minimum 390 in² free area opening
• Use Return Grille, or A/C Coil Cabinet, or any return grille
with a minimum 390 in² free area opening.
For A/C and HP Air Handlers use 1.0 HP Blower Motor On
MSVE72
• Minimum 430 in² free area opening.
• Use return grille, or indoor coil cabinet, or any return
grille with a minimum 430 in² free area opening.
Provisions must be made to permit air in the rooms and living
spaces to return to the air handler. Failure to comply may
cause a reduction in the amount of return air available to the
blower, causing reduced air ow and improper cooling and
heating of the living space.
Return Air Filters
A return air lter is necessary to prevent dust, lint, and other
contaminants from accumulating on the indoor coil and interi-
or surfaces of the air handler. Return air lter options include
a return air lter grille that attaches to a wall, door, or ceiling
or a lter frame that attach directly to the return opening of the
air handler.
Recommended Return Air Filter Grille Size - Bottom Re-
turn Only
800 CFM – 20 X 20 Grille – 324 in²
1000 CFM – 20 X 25 Grille - 414 in²
1200 CFM – 25 X 25 Grille - 414 in²
1400 CFM – 25 X 30 Grille - 644 in²
1600 CFM – 25 X 30 Grille - 644 in²
1800 CFM – 30 X 30 Grille - 784 in²
2000 CFM – 30 X 35 Grille - 924 in²
2400 CFM – 30 X 40 Grille - 1064 in²
Air Filter Base Accessory
The SunTherm Air Filter Base Accessory is available as an
alternative to a return air lter frame. The Air Filter Base
Accessory can be used on the return air end of the air handler
when congured in upow position. The air lter base accessory
is placed over the return plenum in the oor or closet platform
opening and sealed to the plenum or platform using sealant,
caulking material, and/or tape. The air handler is placed on top
of the air lter base and sealed around its perimeter to prevent
air leaks.
NOTE: Filter size adjustment knobs are located on both sides of
the frame. Make sure the ow arrow on the air lter is pointing
towards the air handler.
Figure 4: Air Filter Base Accessory for 1” or 2” Air Filters.
SECTION 4: AIR HANDLER ORIENTATION AND SUPPLY
AIR DUCT INSTALLATION
FILTER BASE ASSEMBLY KIT – FIELD INSTALLED
86ET0002 – 16”X 20” X 2” Small Cabinet
86ET0001 – 20” X 20” X 2” Medium Cabinet
86ET0003 – 20” X 24” X 2” Large Cabinet
Miniumum Air Filter Size
The minimum lter size vs. CFM of airow is shown below
800 CFM = 20 x 20 x 1
1000 CFM = 20 x 25 x 1
1200 CFM = 20 x 30 x 1
1400 CFM = 25 x 30 x 1
1600 CFM = 25 x 30 x 1
1800 CFM = 30 x 30 x 1
2000 CFM = 30 x 40 x 1 or two 30 x 20 x 1
2400 CFM = 30 x 40 x 1 or two 30 x 20 x 1
Pleated Air Filter @ 500 ft/min or Less
800 CFM = 16 x 16 x 1
1000 CFM = 18 x 20 x 1
1200 CFM = 20 x 20 x 1
1400 CFM = 20 x 20 x 1
1600 CFM = 20 x 25 x 1
1800 CFM = 20 x 30 x 1 or two 20 x 15 x 1
2000 CFM = 20 x 30 x 1 or two 20 x 15 x 1
2400 CFM = 25 x 30 x 1 or two 14 x 30 x 1
The air handler is shipped from the factory congured to be
installed in the upow or horizontal right-to-left air-ow position.
Horizontal right-to-left means that when facing the front of the
air handler and the air handler is laid on its side, the supply air
opening is on the left and the return opening is on the right. The
air handler can be eld converted to the horizontal left-to-right
air-ow position using the procedure below.
For eld conversion to left-to-right horizontal applications:
1.Remove the air handler access panels.
2.Remove the indoor coil.
3.Move the condensate drain pan to the right side.
4.Reinstall the indoor coil.
5.Connect the condensate drains and refrigerant lines.
6.Reinstall air handler access panels.
UPFLOW APPLICATIONS
For upow installations, the discharge air outlet is at the top of

CONDENSING UNIT
LIQUID LINE
SUCTION LINE
EVAPORATOR COIL
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 8
SECTION 5: AIR HANDLER INSTALLATION
Prior to installing the air handler, make sure the holes are cut into
the oor for the refrigerant tubing, the drain line, the electrical
wiring, the thermostat wiring and the outdoor unit control wiring.
1. Remove the top shipping cover and corner posts.
2. Remove the bottom shipping cover.
3. Remove the blower and control box access panel.
4. Remove the coil compartment access panel.
5. Place the air handler into position.
6. Connect the electrical supply wires to the line voltage terminal
block and connect the thermostat cable wires to the low
voltage terminal block or low voltage pigtails. Re-install the coil
compartment access panel.
7. Connect the refrigerant lines to the coil.
8. Re-install the blower and control box access panel.
9. Turn the power on to the air handler by following the
the air handler. The air handler must be installed level to permit
proper condensate drainage.
Typical upow installations will be in a closet or basement.
If installed in a closet, the closet should have a platform at least
12 inches in height framed in with an opening centered in the
closet that matches the return air opening on the bottom of
the air handler or an air lter frame if one is installed. The return
air opening can be located in the oor, on a closet door, or in a
side wall next to the air handler cabinet or a return duct can be
attached directly to the platform next to the air handler. If the
return air opening is located in the closet door or side wall above
the platform, the front of the platform must be left open and
a minimum of 6 inches of clearance between the front of the
platform and the closet door must be provided to allow adequate
air-ow from the return air opening into the cavity below the
platform. The 6 inches of clearance is not required if the return
opening is installed completely below the platform allowing the
return air to enter directly into the cavity below the platform or
if the return duct is connected directly to the platform beside the
air handler.
Joints between the air handler, air lter frame, and platform must
be sealed to prevent air leakage. A return air lter grille may be
used instead of a lter frame.
Connect the supply air outlet to a plenum to the top of the air
handler and secure it with screws. If the air handler is installed in
a basement, run supply and return duct work in accordance with
local codes. Use a non-tape sealant such as mastic or an aerosol
sealant to seal between the air handler and ducts to prevent air
leakage.
HORIZONTAL APPLICATIONS
Horizontal applications will normally be used in an attic or crawl
space. This type of installation requires the supply air plenum or
duct to be connected to the supply duct anges and a return air
plenum or duct be attached to the air handler return air inlet.
The supply ducts will be connected to the supply air plenum and
routed through the attic to a register in each room. The opposite
end of the return air duct is attached to a return lter grille
housing. The lter grille is usually located in a wall, just below the
ceiling or the ceiling in a hallway. Use a non-tape sealant such as
mastic or an aerosol sealant to prevent leaks in the ducts and the
plenum.
procedure in the Users Information Manual.
10. Set the thermostat to the desired operating mode and
temperature.
SECTION 6: HYDRONIC HEATING / COOLING
AND REFRIGERANT PIPING
DX Refrigerant Piping:
Air handlers with DX type evaporator coils require liquid
and suction piping sized in accordance with outdoor unit
manufacturer’s instructions. The evaporator coils have sweat
copper connections. Refrigerant lines should be soldered with
silver solder or high temperature brazing alloy. The suction
line must be insulated to avoid condensate from forming and
dropping o. Armaex (or equivalent) with 3/8” (1 cm) minimum
wall thickness is recommended. In severe conditions such as hot
or high humidity areas, 1/2”(1.3 cm) minimum wall thickness
may be required. If the outdoor unit is installed above the indoor
coil, oil traps are required at equal intervals along suction line
as shown in Figure 5. Horizontal suction lines should slope
downward 1 inch for every 20 feet toward outdoor unit. Flow dry
nitrogen through refrigerant lines during soldering operation to
prevent oxidation of the interior of the copper tubes.
• Install 1 oil trap for a height dierence of 15 ft to 25 ft
(4.6 m to 7.6 m) between indoor and outdoor units.
• Install 2 oil traps for a height dierence of 26 ft to 50 ft
(7.9 m to 15.2 m) between indoor and outdoor units.
• Install 3 oil traps for a height dierence of 51 ft to 100 ft
(15.5 m to 30.5 m) between indoor and outdoor units.
• Install 4 oil traps for a height dierence of 101 ft to 150 ft
(30.8 m to 45.7 m) between indoor and outdoor units.
Figure 5: Evaporator Below Outdoor Unit Piping
Thermal Expansion Valves (TXV)
Introduction
SunTherm air handlers can have a factory installed thermal
expansion valve (TXV) or a TXV may be eld installed. The factory
and eld installed TXV’s for this air handler have an internal check
valve making them compatible for both heat pump and cooling
only applications. The TXV has an external pressure equalizer,
non-adjustable superheat, and has a bleed rate of 15%.

HEX NUT
TXV
LIQUID LINE
FEED TUBES
TO COIL
TEFLON SEAL
FOR BODY
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 9
Coil is pressurized with nitrogen from the factory. Relieve
pressure before installing TXV by depressing the Shrader
valve on the coil manifold.
Field Installed TXV Instructions
The TXV assembly is to be installed between the owrator
distributor and the existing liquid line attached to the owrator
distributor as shown in Figure 6.
1. After the coil pressure has been relieved, turn the female swivel
nut counter-clockwise to remove.
2. Remove the piston from the owrator distributor tting using
a small diameter wire or paper clip. (ALWAYS REMOVE PISTON
FROM DISTRIBUTOR BODY WHEN TXV IS INSTALLED).
3. Attach the TXV by connecting the female swivel nut on TXV
outlet to the owrator distributor (aligning Teon seal rst) and
torque swivel nut to 10-30 ft. lbs.
4. Attach liquid line with female swivel nut to male rotolock tting
on TXV inlet (Aligning Teon seal rst) and torque swivel nut to
10-30 ft. lbs.
5. Remove the cap from the male Schrader valve port on the coil
manifold. Attach equalizer tube with 1/4”female are nut
that includes a valve depressor to the male Schrader valve port.
Torque the are nut to 10-30 ft. lb.
Field and Factory Installed TXV Instructions – Sensing Bulb,
Leak Check, Evacuation
1. Install the TXV bulb on the suction line just outside the air
handler cabinet using the two bulb clamps furnished with kit.
2. The bulb should be installed on the upper portion of a
horizontal section of the suction line between 10:00 o’clock and
2:00 o’clock as shown in Figure 7.
3. If the bulb must be installed on a vertical run, the bulb should
be located at least 6 inches from any bend, and on the tubing
side opposite the plane of the bend. On vertical bulb
installations, the bulb should be positioned with the bulb
capillary tube at the top.
4. The bulb must be insulated using thermal insulation to protect
it from the eect of the surrounding ambient temperature.
5. After completing the installation of the TXV (including equalizer
tube), leak check the coil and evacuate the coil through the
liquid and suction line valves on the outdoor unit.
A hard start capacitor on the outdoor unit is normally not
required when a 15% bleed TXV is used, but may be necessary
if compressor starting issues are encountered.
Field Installed TXV Kit Information
R72DB0053HX: R-410A, 1.5 – 2.5 Ton, 15% Bleed,
Inlet: Male Rotolock, Outlet: Female Swivel Nut
R72DB0054HX: R-410A, 3.0 – 5.0 Ton, 15% Bleed,
Inlet: Male Rotolock, Outlet: Female Swivel Nut
Figure 6: Typical TXV Connections
Figure 7: TXV Sensing Bulb Placement
CONDENSATE DRAIN PIPING
The air handler indoor coil drain pan has two ¾”NPT female
primary and two secondary connections (left or right hand). The
horizontal pan has two ¾”NPT female, one primary and one
secondary. Condensate piping from each tting must have a 2”
minimum trap (See Figure 8) and the piping must be routed to
provide enough slope for adequate drainage to a visible area. Do
not pipe these two ttings together into a common drain. If a
secondary drain is not installed, the secondary drain connection
must be capped.

Air handler must be located so that if any connections
should leak, water will not cause damage to the adjacent
area. When such locations can’t be avoided, a suitable
drain pan should be installed under the air handler, not
over 1½”deep, with minimum length and width at least
2” greater than the air handler dimensions and connected
to an adequate drain. Under no circumstances is the
manufacturer to be held liable for any water damage in
connection with this air handler.
2˝ MIN.
DRAIN TRAP
VENT
ANTI-SYPH0N
AIR VENT
2˝ MIN.
2˝ MIN.
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 10
CHILLED AND HOT WATER PIPING
All water pipes must be supported independent of coils to
prevent vibration and stress on coil headers. Swing joints or
exible ttings must be provided to absorb expansion and
contraction strains. Rigid piping reduces the eectiveness of
vibration isolators. Coil water pipes must be adequately vented
in order to prevent air binding. Air handlers are provided with
manual air vents mounted through the manifold panel.
Chilled Water Piping
Supply and return chilled water piping to the coil should be ¾”ID
up to 42,000 BTU/Hr, 1”on air handlers greater than 42,000 BTU/
Hr. Water piping must always be connected so that the entering
water is on the leaving air side of the coil.
Hot Water Piping
If a residential water heater is used for space heating water, do
not exceed a distance of 70 feet between the air handler and the
water heater. The water heater should be the quick recovery type.
Air handler and water heater must be located indoors and not
subject to freezing temperatures.
Total hot water piping should not exceed 140 feet. All hot water
piping to the coil should be copper and ¾”ID and 7/8” OD. CPVC
or PEX piping may be used in applications where the water
temperature does not exceed 150°F. It is recommended that a
water isolation valve and a union be placed in the water lines to
and from the coil that is near the coil for serviceability, repair or
replacement of the coil.
A thermal expansion tank is recommended on any closed loop
system to relieve thermal expansion due to pressure increase.
NOTE: Refer to SECTION 9: FILLING HEATING SYSTEM WITH
WATER AND SYSTEM STARTUP for instructions on lling the
system with water, purging the air from the system, and checking
for leaks once the air handler installation has been completed.
Chilled Water Piping:
Supply and return chilled water piping to the coil should be ¾”ID
up to 42,000 BTU/Hr, 1”on air handlers greater than 42,000 BTU/
Hr. Water piping must always be connected so that the entering
water is on the leaving air side of the coil.
“Massachusetts requires an electronically controlled
pump timer that activates the pump every 6 hours for 60
seconds and limits the distance between the water heater
and air handler to 50 feet max.”
Figure 8: Typical Condensate Trap
When system requires water at temperatures higher than
required for other uses, a means such as a mixing valve
shall be installed to temper the water for those uses in
order to reduce the potential for a scald hazard.
For personal safety, turn the electrical power “OFF” at
the main electrical panel and at the air handler control
box circuit breakers before attempting any service or
maintenance operations. Homeowners should never
attempt to perform any maintenance which requires
opening any of the air handler access panels.

MODEL NO. CFM 160 EWT 20F t 65 F EDB 180 EWT 20F t 65 F EDB
BTUH LAT GPM APD IN-WC WPD FT BTUH LAT GPM APD IN-WC WPD FT
CW018A8K3 600 55,080 1496 56 006 205 67,556 1608 69 006 288
CW024A8K3 800 70,700 1465 72 009 309 86,916, 1652 89 009 332
CW036A8K3 1200 101,327 1429 103 016 468 124,762 1609 128 016 644
CW048A8K3 1600 139,501 1454 142 011 1091 179,219 1637 176 011 1485
CW060A8K3 2000 167,902 1424 171 016 1453 206,377 1601 212 016 1988
CW072A8K3 2400 194,543 1397 198 022 1827 239,408 1570 246 022 2320
MODEL NO. CFM TOTAL SENS LATENT LDB LWB GPM WPDS FT. APD IN-WC
CW018A8K3 600 26,650 17,680 8,970 52.7 48.5 3.0 1.6 0.021
CW024A8K3 800 32,350 22,190 10,160 54.3 54.0 3.5 2.1 0.036
CW036A8K3 1200 41,540 30,430 11,110 56.5 56.1 4.0 3.3 0.049
CW048A8K3 1600 51,940 38,600 13,340 57.6 56.8 5.5 5.5 0.132
CW060A8K3 2000 63,750 47,340 16,410 58.0 57.0 7.0 8.4 0.195
CW072A8K3 2400 78,711 57,242 21,469 58.0 56.8 9.0 9.3 0.280
MODEL NO. CFM 120 EWT 20F t 65 F EDB 140 EWT 20F t 65 F EDB
BTUH LAT GPM APD IN-WC WPD FT BTUH LAT GPM APD IN-WC WPD FT
CW018A8K3 600 26,650 17,680 8,970 52.7 48.5 3.0 1.6 0.021 0.06 1.36
CW024A8K3 800 32,350 22,190 10,160 54.3 54.0 3.5 2.1 0.036 0.09 2.03
CW036A8K3 1200 41,540 30,430 11,110 56.5 56.1 4.0 3.3 0.049 0.16 3.94
CW048A8K3 1600 51,940 38,600 13,340 57.6 56.8 5.5 5.5 0.132 0.11 7.40
CW060A8K3 2000 63,750 47,340 16,410 58.0 57.0 7.0 8.4 0.195 0.16 9.83
CW072A8K3 2400 78,711 57,242 21,469 58.0 56.8 9.0 9.3 0.280 0.22 12.31
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 11
Table 7: Heating Capacity for Water“A” Coil @ Coil 160°F and 180°F
Table 5: Chilled Water“A” Coil Cooling Capacity 80/67°F EAT 45°F EWT
Table 6: Heating Capacity for Water“A” Coil @ 120°F and 140°F

MODEL CFM GPM BTUH LAT ° F LWT ° F APD IWC WPD FT ROWS FPI
MS**18
500 2.7 26,290 116.5
160
0.07 1.2
2
10
600 3.0 29,630 113.5 0.09 1.5
700 3.4 32,690 111.1 0.12 1.8
500 4.0 39,000 137.0 0.10 1.2
3600 4.6 44,500 133.4 0.14 1.5
700 5.1 49,600 130.3 0.18 1.8
500 4.9 47,500 152.6 0.13 2.1
4600 5.6 54,740 149.1 0.18 2.7
700 6.3 61,510 146 0.23 3.3
MS**24
600 3.0 29,630 113.5 0.09 1.5
2800 3.6 35,510 108.9 0.15 2.1
900 3.9 38,140 107.1 0.19 2.4
600 4.6 44,500 133.4 0.14 1.5
3800 5.6 54,300 127.6 0.23 2.2
900 6.0 58,700 125.7 0.28 2.5
600 5.6 54,740 149.1 0.18 2.7
4800 7.0 67,890 143.3 0.29 4.0
900 7.6 73,928 140.7 0.35 4.6
MODEL CFM GPM BTUH LAT ° F LWT ° F APD IWC WPD FT ROWS FPI
M S **2 5 600 3 .4 33, 080 118. 8
160
0. 07 1 .8
2
10
800 4 .1 40, 000 114. 1 0. 11 1 .1
900 4 .4 43, 120 112. 2 0. 13 1 .2
600 4 .7 45, 530 138. 0 0. 10 1 .5
3800 5 .7 56, 060 132. 6 0. 16 2 .2
900 6 .2 60, 880 130. 4 0. 20 2 .6
600 5 .6 54, 160 148. 2 0. 15 3 .1
4800 6 .9 67, 160 142. 4 0. 24 4 .4
900 7 .5 73, 140 139. 9 0. 29 4 .9
M S **3 0 900 4 .4 42, 780 111. 8 0. 14 1 .2
21000 4 .7 45, 680 110. 1 0. 16 1 .4
1200 5 .2 51, 010 107. 2 0. 23 1 .7
900 6 .2 60, 500 130. 0 0. 21 2 .5
31000 6 .7 65, 020 128. 0 0. 25 2 .9
1200 7 .5 73, 410 124. 4 0. 34 3 .7
900 7 .5 73, 140 139. 9 0. 29 4 .9
41000 8 .1 78, 830 137. 7 0. 34 5 .2
1200 9 .2 89, 455 133. 7 0. 46 5 .7
M S **3 6 1000 4 .7 45, 680 110. 1 0. 16 1 .4
21200 5 .2 51, 010 107. 2 0. 23 1 .7
1400 5 .7 55, 830 104. 8 0. 29 2 .1
1000 6 .7 65, 020 128. 0 0. 25 2 .9
31200 7 .5 73, 410 124. 4 0. 34 3 .7
1400 8 .3 81, 080 121. 4 0. 44 1 .4
1000 8 .1 78, 830 137. 7 0. 34 5 .2
41200 9 .2 89, 455 133. 7 0. 46 5 .7
1400 10. 2 99, 230 130. 4 0. 60 6 .6
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 12
Table 8: Hot Water Slab Coil Heating Capacity-Boiler Loop (No Pump) - 65°F EAT 180°F EWT 20°F t / Small Cabinet 1.5 & 2.0 Ton
Table 9: Hot Water Slab Coil Capacity - Boiler Loop (No Pump) - 65°F EAT 180°F EWT 20°F t / Med. Cabinet 2.0, 2.5, 3.0 Ton

MODEL CFM GPM BTUH LAT ° F LAT ° F APD IWC WPD FT ROWS FPI
MS**37
1000 5.4 52,500 116.4
160
0.09 1.6
2
10
1200 6.1 59,100 113.4 0.12 2.0
1400 6.7 65,130 110.9 0.15 2.4
1000 7.5 72,930 135.2 0.13 3.1
3
1200 8.5 83,040 131.8 0.18 1.1
1400 9.5 92,390 128.9 0.23 1.4
1000 8.8 85,910 147.2 0.17 1.3
4
1200 10.1 98,890 144.0 0.23 1.7
1400 11.4 111,020 141.1 0.31 2.1
MS**42
1200 6.1 59,100 113.4 0.12 2.0
2
1400 6.7 65,130 110.9 0.15 2.4
1600 7.3 70,690 108.7 0.19 2.8
1200 8.5 83,040 131.8 0.18 1.1
3
1400 9.5 92,390 128.9 0.23 1.4
1600 10.4 101,100 126.3 0.29 1.6
1200 10.1 98,890 144.0 0.23 1.7
4
1400 11.4 111,020 141.1 0.31 2.1
1600 12.6 122,430 138.6 0.39 2.5
MS**48
1400 6.7 65,130 110.9 0.15 2.4
2
1600 7.3 70,690 108.7 0.19 2.8
1800 7.8 75,860 106.9 0.24 3.2
1400 9.5 92,390 128.9 0.23 1.4
3
1600 10.4 101,100 126.3 0.29 1.6
1800 11.2 109,250 124.0 0.36 1.9
1400 11.4 111,020 141.1 0.31 2.1
4
1600 12.6 122,430 138.6 0.39 2.5
1800 13.7 133,200 136.2 0.47 3.0
MS**60
1800 7.8 75,860 106.9 0.24 3.4
2
2000 8.3 80,690 105.2 0.28 3.9
2100 8.5 83,000 104.4 0.31 4.2
1800 9.5 92,390 128.9 0.36 5.2
3
2000 12.0 116,930 121.9 0.43 8.4
2100 12.4 120,600 120.0 0.46 8.9
1800 13.7 133,200 136.2 0.47 11.0
4
2000 14.7 143,400 134.1 0.57 12.7
2100 15.4 147,245 132.0 0.46 13.9
MS**72
2000 8.3 80,690 101.5 0.45 2.2
2
2200 8.6 83,400 99.9 0.53 2.4
2400 9.0 87,300 98.6 0.61 2.6
2000 12.0 116,930 117.1 0.67 5.2
3
2200 12.3 119,560 115.1 0.79 5.8
2400 12.9 125,700 113.3 0.92 6.3
2000 14.7 143,400 128.9 0.89 9.0
4
2200 15.1 147,400 126.8 1.05 9.5
2400 16.0 155,600 124.8 1.72 10.2
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 13
Table 10: Hot Water Slab Coil Capacity – Boiler Loop (No Pump) 65°F EAT 180°F EWT 20°F t / Large Cabinet 3.0, 3.5, 4.0, 5.0, 6.0 Ton

MODEL CFM GPM BTUH 120°F BTUH 130°F BTUH 140°F BTUH 150°F BTUH 160° APD IWC ROWS FPI
MS**18
500 4 13,600 16,200 18,840 21,510 24,200 0.07
2
10
600 4 14,890 17,760 20,660 23,600 26,570 0.09
700 4 15,990 19,090 22,230 25,410 28,620 0.12
500 4 18,160 21,580 25,000 28,500 32,000 0.10
3600 4 20,170 24,000 27,840 31,700 35,600 0.14
700 4 21,900 26,000 30,280 34,500 38,800 0.18
500 4 21,870 25,930 30,015 34,110 38,225 0.13
4600 4 24,620 29,215 33,820 38,460 43,115 0.18
700 4 27,050 32,108 37,195 42,305 47,440 0.23
MS**24
600 4 14,890 17,760 20,660 23,600 26,570 0.09
2800 4 16,960 20,250 23,600 26,990 30,420 0.15
900 4 17,810 21,280 24,810 28,390 32,010 0.19
600 4 20,170 24,000 27,840 31,700 35,600 0.14
3800 4 23,400 27,900 34,300 34,160 41,600 0.23
900 4 24,800 29,500 34,300 39,160 44,000 0.28
600 4 24,620 29,215 33,820 38,460 43,115 0.18
4800 4 29,210 34,680 40,190 45,725 51,295 0.29
900 4 31,140 36,990 42,845 48,800 54,755 0.35
MODEL CFM GPM BTUH 120°F BTUH 130°F BTUH 140°F BTUH 150°F BTUH 160° APD IWC ROWS FPI
MS**25
600 4 16,210 16,320 22,460 25,630 28,820 0.07
2
10
800 4 18,620 22,220 25,860 29,540 33,260 0.11
900 4 19,620 23,420 27,270 31,170 35,110 0.13
600 4 21,010 25,000 29,030 33,090 37,190 0.10
3800 4 24,490 29,180 33,930 38,720 43,560 0.16
900 4 25,940 30,920 35,960 41,060 46,210 0.20
600 4 24,840 29,415 34,005 38,605 43,200 0.15
4800 4 29,770 35,270 40,785 46,315 51,860 0.24
900 4 31,895 37,790 43,710 49,645 55,595 0.29
MS**30
900 4 19,620 23,420 27,270 31,170 35,110 0.13
21000 4 20,510 24,500 28,540 32,630 36,770 0.16
1200 4 22,050 26,350 30,720 35,150 39,630 0.22
900 4 25,940 30,920 35,960 41,060 46,210 0.20
31000 4 27,230 32,470 37,780 43,160 48,580 0.24
1200 4 29,440 35,140 40,910 46,760 52,670 0.33
900 4 31,895 37,790 43,710 49,645 55,595 0.29
41000 4 33,836 40,100 46,385 52,685 59,010 0.34
1200 4 37,260 44,165 51,104 58,065 65,045 0.46
MS**36
1000 4 20,510 24,500 28,540 32,630 36,770 0.16
21200 4 22,050 26,350 30,720 35,150 39,630 0.22
1400 4 23,340 27,910 32,550 37,260 42,040 0.29
1000 4 27,230 32,470 37,780 43,160 48,580 0.24
31200 4 29,440 35,140 40,910 46,760 52,670 0.33
1400 4 31,270 37,350 43,510 49,750 56,070 0.43
1000 4 33,836 40,100 46,385 52,685 59,010 0.34
41200 4 37,260 44,165 51,104 58,065 65,045 0.46
1400 4 40,195 47,660 55,150 62,670 70,220 0.60
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 14
Table 11: Hot Water Slab Coil Capacity - Factory Pump - 65°F EAT @ Stated EWT / Small Cabinet 1.5 and 2.0 Ton
Table 12: Hot Water Slab Coil Capacity – Factory Pump - 65°F EAT @ Stated EWT / Med. Cabinet 2.0, 2.5, 3.0 Ton

MODEL CFM GPM BTUH120°F BTUH130°F BTUH140°F BTUH150°F BTUH160°F APD IWC ROWS FPI
MS**37
1000 726,320 31,350 36,430 41,570 46,740 0.09
2
10
1200 728,770 34,300 39,900 45,550 51,260 0.12
1400 730,880 36,840 42,880 48,980 55,140 0.15
1000 734,230 40,720 47,280 53,890 60,550 0.13
3
1200 737,800 45,010 52,290 59,640 67,050 0.18
1400 740,860 48,690 56,600 64,590 72,660 0.23
1000 739,630 47,090 54,620 62,190 69,810 0.17
4
1200 744,170 52,530 60,960 69,460 78,020 0.23
1400 748,080 57,220 66,440 75,750 85,130 0.31
MS**42
1200 728,770 34,300 39,900 45,550 51,260 0.12
2
1400 730,880 36,840 42,880 48,980 55,140 0.15
1600 732,720 39,050 45,470 51,970 58,540 0.19
1200 737,800 45,010 52,290 59,640 67,050 0.18
3
1400 740,860 48,690 56,600 64,590 72,660 0.23
1600 743,530 51,890 60,360 68,910 77,550 0.29
1200 744 ,170 52,530 60,960 69,460 78,020 0.23
4
1400 748,080 57,220 66,440 75,750 85,130 0.31
1600 751,490 61,310 71,230 81,250 91,340 0.39
MS**48
1400 730,880 36,840 42,880 48,980 55,140 0.15
2
1600 732,720 39,050 45,470 51,970 58,540 0.19
1800 734,340 41,010 47,770 54,620 61,550 0.24
1400 740,860 48,690 56,600 64,590 72,660 0.23
3
1600 743,530 51,890 60,360 68,910 77,550 0.29
1800 745,870 54,710 63,670 72,720 81,870 0.36
1400 748,080 57,220 66,440 75,750 85,130 0.31
41600 751,490 61,310 71,230 81,250 91,340 0.39
1800 7 54,490 64,910 75,450 86,090 96,820 0.47
MS**60
1800 734,340 41,010 47,770 54,620 61,550 0.24
2
2000 735,780 42,750 49,820 56,990 64,240 0.28
2100 736,450 43,550 50,770 58,080 65,480 0.31
1800 745,870 54,710 63,670 72,720 81,870 0.36
3
2000 747,960 57,220 66,610 76,110 85,710 0.43
2100 748,920 58,380 67,970 77,670 87,480 0.46
1800 754,490 64,910 75,450 86,090 96,820 0.47
4
2000 757,160 68,120 79,200 90,400 101,710 0.57
2100 758,380 69,590 80,930 92,390 103,750 0.62
M S**72
2000 735,780 42,750 49,820 56,990 64,240 0.45
2
2200 736,700 43,800 50,900 58,000 65,200 0.53
2400 738,000 45,300 52,600 60,000 67,500 0.67
2000 747,960 57,220 66,610 76,110 85,710 0.67
3
2200 749,500 58,900 68,300 77,900 87,500 0.79
2400 751,300 61,000 70,800 80,700 90,700 0.92
2000 757,160 68,120 79,200 90,400 101,710 0.89
4
2200 759,200 70,400 81,600 92,900 104,400 1.05
2400 761,500 73,000 84,800 96,500 108,400 1.22
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 15
Table 13: Hot Water Slab Coil Capacity - Factory Pump - 65°F EAT @ Stated EWT / Large Cabinet 3.0, 3.5, 4.0, 5.0, 6.0 Ton

AIR HANDLER MODELS
MSVE 18, 24 MSVT 18, 24 MSVE 25, 30, 36 MSVT 25, 30, 36
Indoor Blower Type ECM Constant Torque ECM Constant Torque
Indoor Blower Amps 1.80 2.67 2.31 4.38
Minimum Circuit Ampacity 2.25 3.34 2.89 5.48
Minimum Wire Size (90°C) #14 #14 #14 #14
Minimum Wire Size (75°C) #14 #14 #14 #14
Minimum Wire Size (60°C) #14 #14 #14 #14
Ground Wire Size ****
Maximum Overcurrent Protection Amps 15 15 15 15
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 16
Power Supply Wiring
The factory air handler internal wiring is complete except for the
power supply and the thermostat wires. See Tables 14 and 15 for
wire size, fuse/circuit breaker size, and ground wire sizes. The use
of cable connectors on incoming power supply wires to relieve
any strain on wiring is required. Follow the steps in the next
column to connect the power supply wires.
Single Circuit Line Voltage Wiring Connections
1. Remove the blower and control box access panel.
2. Remove the control box cover.
3. Install the cable connectors on the 7/8” diameter holes on the
right side of the control box.
4. Strip ½”of the insulation on the end of each wire.
5. Insert the wires through the holes in the cabinet and through
the cable connectors.
6. Insert the black wire into the L1 screw terminal on the terminal
block and tighten the set screw to clamp down on the wire.
7. Insert the white wire into the N screw terminal on the terminal
block and tighten the set screw to clamp down on the wire.
8. Insert the green wire into the ground lug and tighten the
setscrew.
NOTE: If sheathed cable is used, refer to NEC National Electrical
Code (NFPA 70) or the Canadian Electrical Code, Part I (CSA C22.1)
and local codes for additional requirements concerning supply
circuit wiring. Air handler electrical data can be found in Tables 14
and 15.
IMPORTANT - All eld wiring must be rated for 60ºC or higher.
Refer to the wiring diagrams on the air handler or at the back of
this manual for more information.
IMPORTANT - Refer to the NEC National Electrical Code (NFPA 70)
or the Canadian Electrical Code, Part I (CSA C22.1) and local codes
for wiring material requirements
Figure 9: Hydronic Air Handler Control Box
Wiring Connection Locations
SECTION 7: LINE VOLTAGE WIRING
Table 14: Wiring Requirements – 115 VAC Hydronic 18-36 kBTU Models - Single Branch Circuit
+ Refer to the National Electrical Code Table 250-95 for Non-Sheathed Conductor Ground Wire.
* Ground conductor must be the same size and temperature rating as the other conductors listed in Table 13.

AIR HANDLER MODELS
MSVE 37,42,48,60 MSVT 37, 42, 48, 60 MSVE 72
Indoor Blower Type ECM Constant Torque ECM
Indoor Blower Amps 6.31 7.41 8.48
Minimum Circuit Ampacity 7.89 9.26 10.6
Minimum Wire Size (90°C) #14 #14 #14
Minimum Wire Size (75°C) #14 #14 #14
Minimum Wire Size (60°C) #14 #14 #14
Ground Wire Size ***
Maximum Overcurrent Protection Amps 15 15 15
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 17
Table 15: Wiring Requirements – 115 VAC Hydronic 37-72kBTU Models - Single Branch Circuit
+ Refer to the National Electrical Code Table 250-95 for Non-Sheathed Conductor Ground Wire.
* Ground conductor must be the same size and temperature rating as the other conductors listed in Table 14.
Cabinet or cabinet must be permanently grounded in accordance with the National Electrical Code or other applicable codes.
Figure 10: Component Locations – Hydronic Heat Control Box No Pump
Figure 11: Component Locations – Hydronic Heat Control Box With Pump

Max. Thermostat
Wire Length
Thermostat Wire
Gauge
Thermostat Wire
Maximum Current
0 - 100 Feet 22 3.0 Amps
0 - 125 Feet 20 3.0 amps
0 - 250 Feet 18 3.0 amps
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 18
Thermostat Wiring
Thermostat wires connect through side of air handler and should
be no smaller than 22 gauge. Refer to Table 15 for recommended
wire gauge, lengths and maximum current for each wire gauge.
Thermostat wires can enter through the side or top of the air
handler. When bringing wiring through the top or side of the
air handler, cable connectors must be installed to hold wiring in
place and to relieve any strain on the wiring.
The thermostat wire colors and the typical heating/cooling
connections are listed in Table 17. The thermostat wire colors and
the typical heat pump connections are listed in Table 18.
Thermostat Installation
The thermostat heat anticipator must be set at 0.4 amps if the
thermostat has a manual heat anticipator adjustment. This
setting should be checked at the time of installation.
The thermostat may be a“self-setting”type in which no heat
anticipator setting will be found on the thermostat, eliminating
the need for eld adjustment.
The thermostat should be located on an inside wall in an
open area or hallway to more closely sense average room air,
preferably where there is air movement back to air handler.
The thermostat should not be located within 3 feet of from any
windows and should be 52 to 66 inches above the oor. Do not
place the thermostat within 3 feet of any supply air register.
Maintenance, operating, and/or programming instructions are in
the envelope shipped with the thermostat. The envelope should
be given to the homeowner or user after the installation
is complete.
Air Handler and Outdoor Unit With Separate Transformers
If the air-hander and the outdoor unit have separate
transformers, it is important to use a thermostat with isolated
heating and cooling contacts“RC” and “RH”to prevent
interconnection of Class II 24 Volt Systems. Most modern
thermostats have separate heating and cooling contacts for
use with homes that have an air handler and outdoor unit that
are completely separate and each have a 24 VAC transformer
for system control. These thermostats have a“RC” terminal for
cooling and a“RH”terminal for heating. Connect the outdoor unit
RED wire from the“R” terminal on the
outdoor unit to the“RC” terminal on the thermostat and the RED
air handler pigtail wire to the“RH” terminal on the thermostat.
If the air handler and outdoor unit using separate transformers
are both connected to the thermostat“R”terminal, a transformer
burnout can occur or either the air handler or outdoor unit
control system could go into lockout mode. If an air handler and
outdoor unit with separate transformers are being installed and
SECTION 8: THERMOSTAT WIRING AND CONNECTIONS
Do not locate thermostat within three feet of any of the
following items:
1. Supply air registers
2. Lights or heat lamps
3. Aquariums
4. Televisions, stereo, ampliers, surround sound systems
5. Stoves or any cooking appliance
6. Refrigerator
7. Clothes washer or dryer
8. Hot water tank
9. Sink or near any hot water
10. Within 15 feet of any electric space heater
11. Within 2 feet of any direct sunlight
Table 16: Low Voltage Wire Gauge and Maximum Lengths
the thermostat does not have the“RC”and “RH”terminals, a new
thermostat with“RC”and “RH”terminals must be purchased and
installed.
IMPORTANT: Cycle the air handler and outdoor unit separately to
make sure both operate correctly.
Separate Heating and Outdoor Units With Separate
Thermostats
If the home has a central heating and cooling system, but
the hydronic heat and DX cooling are controlled by separate
thermostats, the use of a thermostat interlock switch is required
in order to prevent heating and cooling from operating at the
same time.
When using separate heating and cooling thermostats,
a thermostat interlock system must be provided to
prevent simultaneous operation of the hydronic heat and
cooling. Simultaneous operation can result in equipment
overheating, equipment damage, and wasted energy.
DO NOT connect the YELLOW wire to the thermostat unless
an outdoor unit is installed.

CC C
YY
W/E
G
RH
RC
Y2*
W/1
G
R
AIR HANDLER
TRANSFORMER
24 VAC
24 VAC
COMMON
COOLING UNIT
OUTDOOR SECTION
AIR HANDLER
THERMOSTAT
JUMPER
CLO
FREEZE
PROTECTION
Y/Y1
*MSVE ONLY
CC C
YY
W/E
G
RH
RC
O/B
Y2*
O/B
Y/Y1
W/1
G
R
R
AIR HANDLER
TRANSFORMER
24 VAC
24 VAC
COMMON
HEAT PUMP UNIT
OUTDOOR SECTION
AIR HANDLER
THERMOSTAT
JUMPER
W/E
W2
FOLLOW MANUFACTURER'S
INSTRUCTIONS
CLO
FREEZE
PROTECTION
*MSVE ONLY
WIRE COLOR DESCRIPTION LETTER
CODE
AIR HANDLER PIG TAIL
WIRE CONNECTION
THERMOSTAT
CONNECTION
OUTDOOR UNIT
CONNECTION
RED 24 VAC R RED R N/A
WHITE Heat W WHITE W N/A
GREEN Indoor Fan G GREEN G N/A
YELLOW Cooling / Opt. 1st Stage Cooling Y /Y1 YELLOW Y /Y1 Y /Y1
BLUE Optional 2nd Stage Cooling Y2 BLUE Y2 Y2
BROWN 24 VAC Common C BROWN C C
WIRE COLOR DESCRIPTION LETTER
CODE
AIR HANDLER PIG TAIL
WIRE CONNECTION
THERMOSTAT
CONNECTION
OUTDOOR UNIT
CONNECTION
RED 24 VAC R RED R R
WHITE Heat W WHITE E (Thermostat)
W (Air Handler)
See Outdoor
Unit Instructions
GREEN Indoor Fan G GREEN G N/A
YELLOW Cooling / Opt. 1st Stage Cooling Y /Y1 YELLOW Y /Y1 Y /Y1
BLUE Optional 2nd Stage Cooling Y2 BLUE Y2 Y2
BROWN 24 VAC Common C BROWN C C
ORANGE Heat Pump Reversing Valve Solenoid
(Most Outdoor Unit Brands) O N/A O
O
See Outdoor
Unit Instructions
ORANGE Heat Pump Reversing Valve Solenoid
(Some Outdoor Unit Brands) B N/A B
B
See Outdoor
Unit Instructions
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 19
Figure 12: Typical Low Voltage Connections -
Hydronic Heating and Single-Stage Cooling
Figure 13: Typical Low Voltage Connections -
Hydronic Heating and Single-Stage Heat Pump
Table 17: Typical Heat / Cool Thermostat Wire Color Colors and Low Voltage Connections
Table 18: Typical Heat Pump Thermostat Wire Colors and Low Voltage Connections

MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 20
Typical Heating/Cooling Thermostat Wiring Connections
1. Remove blower/control box access panel.
2. Remove the control box cover.
3. Insert the low voltage wire cables from the thermostat and
outdoor unit through the 9/16”diameter hole located in the
top or right side of the air handler and into the control box.
Place the ends of these cables next to the air handler low
voltage terminal block (LVTB) or air handler low voltage
pigtails. Secure these cables in the 9/16”diameter hole with a
strain relief to prevent wire connections from being pulled
apart.
4. Strip ½”of the insulation on the end of each thermostat cable
wire.
5. Connect the RED (24 VAC) wire from the thermostat cable to
the “R”screw terminal on the LVTB or to the RED air handler
pigtail with a wire nut.
6. Connect the WHITE wire from the thermostat cable to the“W”
screw terminal on the LVTB or to the WHITE air handler pigtail
with a wire nut.
7. Connect the GREEN (indoor fan) wire from the thermostat
cable to the“G”screw terminal on the LVTB or to the GREEN air
handler pigtail with a wire nut.
8. For MSVT models (constant torque motor), connect the two
YELLOW (cooling) wires from the thermostat and outdoor unit
cables to the“Y”screw terminal on the LVTB or to the YELLOW
air handler pigtail.
9. For MSVE models (ECM motor), connect the YELLOW wire from
the thermostat to both the YELLOW “Y1” and BLUE“Y2”
air handler pigtails with a wire nut for single-stage cooling
applications to assure full nominal airow. For 2-stage cooling
applications, connect the wire from the thermostat“Y1”
terminal to the YELLOW “Y1”air handler pigtail and connect
the wire from the thermostat“Y2”terminal to the BLUE “Y2” air
handler pigtail.
10. Connect the two BROWN (24 VAC common) wires from the
thermostat and outdoor unit cables to the“C” screw terminal
on the LVTB or to the BROWN air handler pigtail with a wirenut.
Typical Heat Pump Thermostat Wiring Connections
1. Remove the blower / control box access panel.
2. Remove the control box cover.
3. Insert the low voltage wire cables from the thermostat and
outdoor unit through the 9/16”diameter hole located in the top
or side of the air handler and into the control box. Place the
ends of these low voltage cables next to the air handler low
voltage terminal block (LVTB) or low voltage pigtails. Secure
these cables in the 9/16” diameter hole with a strain relief to
prevent wire connections from being pulled apart.
4. Strip ½”of the insulation on the end of each thermostat wire.
5. Connect the RED (24 VAC) wire from the thermostat cable to the
“R” screw terminal on the LVTB or to the RED air handler pigtail
with a wire nut.
6. Connect the WHITE (emergency heat) wire from the
thermostat’s “E” terminal to the “W”screw terminal on the air
handler LVTB or to the WHITE air handler pigtail. If applicable,
also connect the wire from the outdoor control board that calls
for supplemental heat during the defrost cycle to the“W”
terminal on the air handler LVTB or to the WHITE air handler
pigtail. Refer to the outdoor unit installation instructions for
additional information.
7. Connect the WHITE (emergency heat) wire from the
thermostat’s “E” terminal to the “W”screw terminal on the air
handler LVTB or to the WHITE air handler pigtail. If applicable,
also connect the wire from the outdoor control board or pigtail
that calls for supplemental heat during the defrost cycle to the
“W” terminal on the air handler LVTB or to the WHITE air
handler pigtail. Refer to the outdoor unit installation
instructions for additional information.
8. Connect the GREEN wire from the thermostat“G”terminal to
the“G”screw terminal on the LVTB or to the GREEN air handler
pigtail with a wire nut.
9. For MSVT models (constant torque motor), connect the
YELLOW wire from the thermostat“Y”terminal and the YELLOW
wire from the outdoor unit“Y”terminal or pigtail to the“Y”
screw terminal on the LVTB or to the YELLOW air handler
pigtail with a wire nut.
10. For MSVE models (ECM motor), connect the YELLOW wire from
the thermostat to both the YELLOW “Y1” and BLUE“Y2”
air handler pigtails with a wire nut for single-stage cooling
applications to assure full nominal airow. For 2-stage cooling
applications, connect the wire from the thermostat“Y1”
terminal to the YELLOW “Y1” air handler pigtail and connect
the wire from the thermostat“Y2”terminal to the BLUE “Y2” air
handler pigtail.
11. Connect the BROWN (24 VAC common) wire from the
thermostat“C” terminal and the wire from the outdoor unit“C”
terminal or 24 VAC common pigtail to the“C”screw terminal
on the LVTB or to the BROWN air handler pigtail with a wire nut.
12. Connect the ORANGE (reversing valve solenoid) wire
from the thermostat with the ORANGE or BLUE wire from the
“O” or “B” terminal on the outdoor unit with a wire nut.
Refer to the outdoor unit installation instructions for
additional information
Thermostat Heat Anticipator
Some thermostats have a heat anticipator that must be set to 0.4
in order to function correctly. If the heat anticipator setting is too
low the air handler will short cycle. If the heat anticipator setting
is too high the air handler will run long cycles thus causing the
temperature to overrun the temperature setting. This will cause
the homeowner to feel hot by the time the blower completes its
cycle; then cold, by the time the air handler cycles on again.