Toshiba Carrier MMD-UP0121VHG-UL User manual

035-000051-002 Page 1 of 64 MMD IOM 1.3 8-15-2023
Vertical Air Handling Unit
Installation, Operation and Maintenance Manual
Model name: For Commercial Use
MMD-UP0121VHG-UL
MMD-UP0181VHG-UL
MMD-UP0241VHG-UL
MMD-UP0301VHG-UL
MMD-UP0361VHG-UL
MMD-UP0421VHG-UL
MMD-UP0481VHG-UL
MMD-UP0601VHG-UL

035-000051-002 Page 2 of 64 MMD IOM 1.3 8-15-2023
THIS PAGE INTENTIONALLY LEFT BLANK

035-000051-002 Page 3 of 64 MMD IOM 1.3 8-15-2023
Installaon, Start-Up
and Service
Instrucons
MMD Series Air Handling Unit
Installation, Operation and Maintenance Manual

035-000051-002 Page 4 of 64 MMD IOM 1.3 8-15-2023
THIS PAGE INTENTIONALLY LEFT BLANK

035-000051-002 Page 5 of 64 MMD IOM 1.3 8-15-2023
GENERAL
Installation and maintenance are to be per-
formed only by qualified personnel who are fa-
miliar with local codes and regulations and are
experienced with HVAC equipment of this type.
WARNING: Sharp edges, coil surfaces
and rotating fans are a potential injury
hazard – avoid contact.
WARNING: Hazardous voltage – Discon-
nect and Lock Out all incoming power
sources before servicing or installing unit.
ELECTRIC SHOCK CAN CAUSE DEATH.
WARNING: This equipment may be in-
stalled well above finished floor—Use ex-
treme caution when working at heights.
SAFETY WARNING:
Installer should pay particular attention to
the following words:
NOTE–intended to clarify or make instal-
lation easier.
CAUTION–given to prevent equipment
damage.
WARNING–to alert installer that personal
injury and/or equipment damage may
result if installation procedure is not
properly followed.
WARNING
CHECK the assembly and component weights to
be sure that the rigging equipment can handle
them safely.
Note also, the centers of gravity and any specific
rigging instructions.
CHECK for adequate ventilation so that fumes will
not migrate through ductwork to occupied spaces
when welding or cutting inside air-handling unit
cabinet or plenum.
WHEN STEAM CLEANING COILS be sure that
the area is clear of personnel.
DO NOT attempt to handle access covers and re-
movable panels on outdoor units when winds are
strong or gusting until you have sufficient help to
control them. Make sure panels are properly se-
cured while repairs are being made to a unit.
DO NOT remove access panel fasteners or open
access doors until fan is completely stopped. Pres-
sure developed by a moving fan can cause exces-
sive force against the panel which can injure per-
sonnel.
DO NOT work on dampers until their operators are
disconnected.
BE SURE that fans are properly grounded before
working on them.
Failure to follow these warnings could result in per-
sonal injury or equipment damage.
DANGER
NEVER enter an enclosed fan cabinet or reach into
a unit while the fan is running.
LOCK OPEN AND TAG the fan motor power dis-
connect switch before working on a fan. Take fuses
with you and note removal on tag. Electric shock
can cause personal injury or death.
LOCK OPEN AND TAG the electric heat coil power
disconnect switch before working on or near heat-
ers.
Failure to follow these warnings could lead to per-
sonal injury or death.
UNPACKING-CHECK FOR DAMAGE!
Immediately inspect each unit for dam-
age upon receipt.
• Inspect units for external and concealed
damage immediately.
• File any damage claims in accordance
with the Freight Damage Policy and
Terms and Conditions.
• Do not repair damaged units without
written authorization.
• Protect stored units from damage.
GENERAL INFORMATION

035-000051-002 Page 6 of 64 MMD IOM 1.3 8-15-2023
PRODUCT NOMENCLATURE

035-000051-002 Page 7 of 64 MMD IOM 1.3 8-15-2023
PRODUCT NOMENCLATURE—ACCESSSORIES
Notes: 1. Plenums have 1/2" berglass insulaon. 2. Plenums and lter boxes have lter slot that will accept 4" thick lter or 2" thick lter. To use with 4"
thick lter lter, remove 2” lter, remove lter rail, and add eld-supplied 4” thick lter.
3. Return air Grille(s) and duct collars are eld-provided and eld-installed. 4. Plenums have return air duct openings on front, right and le sides. Front and right sides have at co-
vers that can be relocated as needed. Opening in rear can be cut in the eld.
Product name Product name (Detailed) Model Name (Final)
Product size
(H XW XD)
Packing size
(H XW XD)
Weight
(lbs,
Net)
Weight
(lbs,
Gross)
Electric Heater 1kW for 12-60k Model TCB-HT101VDGUL 6.7" X11.0" X22.5" 9" X13" X27" 4.0 6.0
Electric Heater 3kW for 12-60k Model TCB-HT301VDGUL 6.7" X11.0" X22.5" 9" X13" X27" 5.0 7.0
Electric Heater 5kW for 12-60k Model TCB-HT501VDGUL 6.7" X11.0" X22.5" 9" X13" X27" 5.0 7.0
Electric Heater 6kW for 18-60k Model TCB-HT601VDGUL 6.7" X11.0" X22.5" 9" X13" X27" 5.0 8.0
Electric Heater 8kW for 30-60k Model TCB-HT801VDGUL 6.7" X11.0" X22.5" 9" X13" X27" 6.0 8.0
Electric Heater 9.5kW for 30-60k Model TCB-HT951VDGUL 6.7" X11.0" X22.5" 9" X13" X27" 6.0 8.0
Plenum Chamber For 12-24k Model, with 2" Filter, Single Pkg TCB-PL2S241VDGUL 20.2" X 17.5" X22.2" 22" X23" X28" 36.0 43.0
Plenum Chamber For 30-36k Model, with 2" Filter, Single Pkg TCB-PL2S361VDGUL 20.2" X 20.0" X25.2" 22" X26" X31" 41.0 49.0
Plenum Chamber For 42-48k Model, with 2" Filter, Single Pkg TCB-PL2S481VDGUL 24.2" X 22.0" X27.2" 26" X28" X33" 49.0 59.0
Plenum Chamber For 60k Model, with 2" Filter, Single Pkg TCB-PL2S601VDGUL 24.2" X 24.0" X31.2" 26" X30" X37" 60.0 71.0
Filter Box For 12-24k Model, 2" MERV 8 Filter TCB-FB2F241VDGUL 4" X17.5" X22.2" 8" X21" X26" 12.0 15.0
Filter Box For 30-36k Model, 2" MERV 8 Filter TCB-FB2F361VDGUL 4" X20.0" X25.2" 8" X23" X29" 14.0 18.0
Filter Box For 42-48k Model, 2" MERV 8 Filter TCB-FB2F481VDGUL 4" X22.0" X27.2" 8" X25" X31" 15.0 19.0
Filter Box For 60k Model, 2" MERV 8 Filter TCB-FB2F601VDGUL 4" X24.0" X31.2" 8" X27" X35" 20.0 25.0

035-000051-002 Page 8 of 64 MMD IOM 1.3 8-15-2023
Pre-installation
1. Check items received against packing list.
2. Do not stack unit components or accesso-
ries during storage. Stacking can cause
damage or deformation.
3. If unit is to be stored for more than 2 weeks
prior to installation, observe the following
precautions:
a. Choose a dry storage site that is rea-
sonably level and sturdy to prevent un-
due stress or permanent damage to the
unit structure or components. Do not
store unit on vibrating surface. Damage
to stationary bearings can occur. Set
unit off ground if in heavy rain area.
b. Remove all fasteners and other small
parts from jobsite to minimize theft. Tag
and store parts in a safe place until
needed.
c. Cover entire unit with a tarp or plastic
coverall. Extend cover under unit if
stored on ground. Secure cover with
adequate tie-downs or store indoors.
Be sure all coil connections have pro-
tective shipping caps.
d. Monthly — Remove tarp from unit, en-
ter fan section through access door or
through fan inlet, and rotate fan and
motor slowly by hand to redistribute the
bearing grease and to prevent bearing
corrosion.
Rigging — Do not remove shipping skids or
protective covering until unit is ready for final
placement. Use slings and spreader bars as ap-
plicable to lift unit. Do not lift unit by coil connec-
tions or headers.
Do not remove protective caps from coil
piping connections until ready to connect
piping.
WARNING-AUXILIARY DRAIN PAN
RECOMMMENDED:
This product has an auxiliary condensate drain
which should be piped to a condensate overflow
sensor or safe drain location or both to protect
the equipment and property from damage in the
case of condensate overflow.
In addition, the International Mechanical Code
(IMC) section 307.2.3 requires the use of auxil-
iary drain pans. Many municipalities have
adopted this code.
This practice represents the standard for profes-
sional installation whether or not this code has
been adopted in a specific municipality or terri-
tory. As such, water damages that would have
been prevented had an auxiliary pan been de-
ployed will not be considered for compensation.
This position is taken regardless of whether the
source of the moisture was specified as a po-
tential failure mode in the applicable building
code or not. A freeze burst, cracked drain pan,
failed weld, or corrosion induced leak are some
of the potential failure modes that are mitigated
when an auxiliary pan is properly installed. Pro-
fessional installers recognize the value of pro-
tecting customer assets against foreseeable
events. Customers who choose to avoid the
cost of common protective measures waive their
right to seek damages when those foreseeable
events occur. If the product is located above a
living space or where damage may result from
condensate overflow, install a watertight pan of
corrosion-resistant metal beneath the unit to
catch over-flow which may result from clogged
drains or from other reasons. Provide proper
drain piping for this auxiliary pan. Consult local
codes for additional precautions before installa-
tion.
Unpackaging
1. Remove all packaging and any foreign mate-
rial from unit.
2. Check blower wheel for free rotation.
3. Check copper lines, coil etc. for internal or
hidden damage.
Return Air and Unit Orientation
Units may be positioned in several configura-
tions depending on the return air configura-
tion selected—see Figure 1.
NOTE: Right and left return units are not
recommended for horizontal installation.
Service Clearance
The fan coil is completely serviceable from
the front. Units are approved for 0” (zero
inches) of clearance. This allows substantial
freedom in the positioning of the unit to best
serve the requirements of the structure.
INSTALLATION
Unit Support
Floor mounting: Unit may be mounted on a
housekeeping pad, floor, platform or plenum.
Provide a suitable isolation pad to minimize
sound transmission to the structure. CAU-
TION! Make sure to allow enough eleva-
tion to permit construction of the conden-
sate trap. Also allow enough elevation
and clearance for opening the filter door
(removes to the front). See Service Clear-
ances.
Install the unit so that it is level or pitches
slightly –(1/8 inch) – toward the condensate
drain connection.
Anchor the unit to the plenum or platform
through the bottom flange using 2ea #10
sheet metal screws on each side (4 screws
total).

035-000051-002 Page 9 of 64 MMD IOM 1.3 8-15-2023
INSTALLATION
Figure 1
Return Configurations and
Unit Orientations

035-000051-002 Page 10 of 64 MMD IOM 1.3 8-15-2023
INSTALLATION—SERVICE CLEARANCES
NOTES:
1. BLOWER SERVICE REQUIRES FRONT ACCESS ONLY.
2. RECOMMENDED BUT NOT NECESSARY: ALLOW 12”
ON RIGHT AND LEFT SIDES FOR SIGNIFICANT BUT
INFREQUENT SERVICE PROCEDURES SUCH AS
DRAIN PAN OR COIL REPLACEMENT.
3. WHEN UNIT IS INSTALLED HORIZONTALLY (LYING ON
RIGHT SIDE), CLEARANCES REMAIN THE SAME AS
INDICATED ABOVE, EXCEPT TRAP CLEARANCE EX-
TENDS BELOW THE UNIT.
A B C D E F
12/18/24 36.0 36.0 36.0 22.0 6.0 9.0
30/36 36.0 36.0 36.0 25.0 6.0 10.0
42/48 36.0 36.0 36.0 27.0 6.0 11.0
60 36.0 36.0 36.0 31.0 6.0 11.0
G H L M N
12/18/24 12.0 7.0 19.4 35.7 45.0
30/36 12.0 7.0 23.5 40.6 50.0
42/48 12.0 7.0 26.3 43.6 54.0
60 12.0 7.0 28.3 46.4 56.0
UNIT
SIZE
CLEARANCE DIMENSION
(INCHES)

035-000051-002 Page 11 of 64 MMD IOM 1.3 8-15-2023
Ceiling Suspension: Mount the unit in ceiling-
suspended horizontal orientation per suspen-
sion details (Figure 4a). Unit is NOT intended
to be wall mounted. Consult a qualified struc-
tural engineer for special mounting considera-
tions.
Install the unit so that it pitches slightly –(1/8
inch) – toward the condensate drain connec-
tion.
Condensate Drain
Install a trapped condensate drain line at unit
drain connection. All MMD units have 3/4 in.
FPT condensate main and auxiliary drain
connections.
Provide adequate trap clearance (trap depth)
beneath the unit as indicated in Fig. 3. Pro-
vide freeze-up protection as required to in-
sure reliable condensate drainage. Freeze protec-
tion measures are customer-supplied and in-
stalled.
Pipe to condensate drain using PVC or copper or
other suitable material. Pitch drain piping down-
ward at a minimum slope of 1/8 inch per foot.
Pipe auxiliary drain to “tell tale” drain location or
floor drain to clearly indicate when condensate
drain service is required. Alternately, use a field-
provided condensate overflow detection device in
the auxiliary drain connection to provide alarm or
other controls action when the drain pan fills to the
level of the auxiliary drain.
Placing Unit In Ductwork
1. Utilize flexible transitions on supply and return
connections to reduce noise and vibration trans-
mission to the structure.
2. When the connecting return air duct is smaller
than the coil inlet opening, construct the transi-
tion piece so that the vertical and horizontal di-
mensions of the transition piece do not increase
more then one inch for every seven inches of
length of the transition piece.
3. Provide at least three feet of straight duct work
preceding the unit inlet.
INSTALLATION
WARNING
INSURE THAT THE UNIT IS ADE-
QUATELY SUPPORTED FROM
STRUCTURE TO PREVENT DAMAGE
OR INJURY CAUSED BY FALLING
EQUIPMENT! If uncertain about how
to connect to the structure, consult a
qualified structural engineer.
Fig. 3 — Condensate Drain
Duct Insulation and Vapor Proofing:
Properly select and install duct insulation as
required by the application.
All externally insulated duct work must have an
adequate vapor seal for summer operation. This
is particularly important where the duct is ex-
posed to highly humid conditions in such places
as attics, vented crawl spaces, unconditioned
basements, and utility rooms. The vapor seal
prevents condensation of moisture in the insu-
lating material and subsequent loss of its insu-
lating value.
NOT TO SCALE
MAINTAIN THESE DIMENSIONS FOR ADEQUATE TRAP
SEAL:
A = 3.5” MINIMUM
B = 2.0” MINIMUM
NOTES:
1. CONDENSATE DRAIN PIPING RECOMMENDATIONS:
A. MINIMUM 3/4” Φ PIPE SIZE
B. COPPER OR PVC PIPE MATERIAL
C. USE DIELECTRIC UNION FOR DISSIMILAR METALS.
D. INSULATE PER PROJECT SPECIFICATIONS.
2. PAD OR PLENUM HEIGHT AS REQUIRED TO INSTALL
TRAP AND CONDENSATE DRAIN PIPING.
3. AVOID BLOCKING FILTER SERVICE ACCESS WHEN
INSTALLING CONDENSATE DRAIN PIPING.

035-000051-002 Page 12 of 64 MMD IOM 1.3 8-15-2023
Figure 4a
CEILING SUSPENSION DETAILS
MMD AIR HANDLER

035-000051-002 Page 13 of 64 MMD IOM 1.3 8-15-2023
INSTALLATION
CAUTION
Direct-expansion coils are shipped pressurized
with dry nitrogen. Release pressure from the coil
through valves in protective caps before remov-
ing caps.
Do not leave piping open to the atmosphere un-
necessarily. Water and water vapor are detri-
mental to the refrigerant system. Until the piping
is complete, recap the system and charge with
nitrogen at the end of each workday. Clean all
piping connections before soldering joints.
Failure to follow these procedures could result in
personal injury or equipment damage.
Refrigerant Piping
Refrigerant coils have liquid and suction
line connections through the front of the
cabinet. CAUTION: Use proper care when
brazing including use of heat sink (wet
cloth or other method) to prevent damage
to liquid line and suction line components
(see Figure 4b)
Size and install refrigerant lines in accord-
ance with the condensing unit manufactur-
er’s instructions. Provide insulation on the
suction line, to prevent condensation. Pro-
vide insulation on the liquid line if unit to be
used for heat pump service or if otherwise
required.
System Design Regulation
When connecting MMD units in the VRF
system (mix or all), refer to the VRF Sys-
tem standard piping design regulations.
Fig. 4b — Connection of Refrigerant
Piping—Brazing Details
Apply brazing to
full circumference
Wrap AHU-side
piping with wet cloth
before brazing.
Connecting pipe size is shown in the following table.
NOTE: Be sure to use the reducer pipe (shipped
loose with the air handler) so as to match the con-
necting pipe size for unit sizes 012 and 018.
Unit Size Gas side Liquid side Gas side Liquid side
012 3/8" 1/4" 5/8" to 3/8" 3/8" to 1/4"
018 1/2" 1/4" 5/8" to 1/2" 3/8" to 1/4"
024
030
036 5/8" 3/8" Unneccesary Unneccessary
042
048
060
Reducer pipe
Indoor connecting pipe

035-000051-002 Page 14 of 64 MMD IOM 1.3 8-15-2023
INSTALLATION—ELECTRIC HEAT
Electric Heater Accessory
The electric heater may be factory-installed or
field-installed. See Figures 5 through 8.
Removal Procedure:
To remove the electric heater,
1. Disconnect and lock out electrical power
from the unit. Remove heater access panel.
Disconnect power wires from the power
switch—DANGER! - MAKE SURE there is no
voltage on these wires before disconnecting!
2. Disconnect 2 harness connectors at the
blower deck.
3. Remove 2 screws holding heater support
feet to the blower deck.
4. Remove 4 screws that mount the heater to
the heater bulkhead. Handle heater carefully
to avoid damaging the wire heating elements.
Remove heater from the unit.
DANGER
WARNING: Hazardous voltage. Only qualified
personnel must install the electrical service. Dis-
connect and Lock Out all incoming power sources
before connecting to electrical service.
WARNING: This appliance must be permanently
grounded in accordance with the National Electrical
Code and local code requirements.
WARNING: For use with copper conductors only.
Fig. 5 — Heater Accessory Installed
(right side panel not shown)
Fig. 6 — Heater Accessory Installed
(right side and heater access panels
not shown)

035-000051-002 Page 15 of 64 MMD IOM 1.3 8-15-2023
INSTALLATION—ELECTRIC HEAT
Electric Heater Accessory-MMD size 12, 18
and 24
The electric heater must be adjusted to fit unit
sizes 1-ton, 1.5-ton and 2-ton unit models
(MMD-AP0120, MMD-AP0180, MMD-
AP0240). See Figures 6b through 6e.
Switch Plate Adjustment Procedure:
To adjust the switch plate to shorten the heat-
er length, remove the two mounting screws
that attach the switch plate to the heater plate.
Screws install from the bottom.
Next, slide the switch plate toward the heater
plate, line up the two holes, and re-install the
two screws. The final assembly is shorter to
match the shallower depth of the 1/1.5/2.0 ton
size cabinets.
DANGER
WARNING: Hazardous voltage. Only qualified
personnel must install the electrical service. Dis-
connect and Lock Out all incoming power sources
before connecting to electrical service.
Fig. 6b — Heater—Long Format
(mounting screws shown by arrows)
Fig. 6e
Heater—Short
Format
(mounting
screws shown
by arrows)
Fig. 6c
Heater—Long
Format
(Bottom view;
mounting
screws shown
by arrows)
Fig. 6d
Heater—Short
Format
(Bottom view;
mounting
screws shown
by arrows)
HEATER
PLATE
SWITCH
PLATE

035-000051-002 Page 16 of 64 MMD IOM 1.3 8-15-2023
INSTALLATION-ELECTRIC HEAT DANGER
WARNING: Hazardous voltage. Only qualified
personnel must install the electrical service. Dis-
connect and Lock Out all incoming power sources
before connecting to electrical service.
Install Procedure:
To install the electric heater,
1. Disconnect and lock out electrical power from
the unit. Remove heater access panel. Discon-
nect field power wires from the unit power wires.
DANGER! - MAKE SURE there is no voltage
supply to the unit before proceeding!
2. Disconnect and discard 1 harness connector at
the blower deck.
3. Remove blank plate from heater access panel
(covers square hole for breaker style power
switches).
4. Remove SAT sensor and sensor holder from
heater bulkhead and reposition on unit discharge
ductwork routing through auxiliary SAT sensor
hole on top panel.
5. Install SAT 3 feet after the first 90 degree turn
in the discharge ductwork.
6. Remove plate on the heater bulkhead (4
screws).
7. Install heater by carefully supporting the heater
and inserting it into the opening in the heater bulk-
head. NOTE: Make sure to guide the pin into the
hole at the back of the heater shroud. Secure the
heater to the bulkhead with 4 screws.
8. Connect 2 wiring harnesses (male) to the
matching female receptacles in the blower deck.
9. Connect field wiring to the breaker-style power
Fig. 7 — Heater Accessory Removal
(right side and heater access panels
not shown for clarity)
switches on the front of the heater. WARNING! Be
sure to provide the appropriate wire size and
branch circuit protection as required by the unit
nameplate!
10. Install the heater access panel.
11. Install the silicone cover “boot” over the top of
the power switches. This protects them from dust
buildup. The switches may be activated through the
flexible boot material.
12. Mark the nameplate label with the matching
heater kW rating. Label is located on the exterior of
the front top panel.
Fig. 8 — Heater
Accessory
Installed
PIN
HEATER
SHROUD
HEATER
ACCESS
PANEL
COVER
BOOT
HEATER
SHROUD
HEATER
ASSEMBLY
HEATER
BULKHEAD
POWER
SWITCH(ES)

035-000051-002 Page 17 of 64 MMD IOM 1.3 8-15-2023
Typical wiring diagrams are shown on the following
pages FOR REFERENCE. Always refer to the wir-
ing diagram on the air handling unit for actual wir-
ing.
NOTE: CHECK MOTOR RATING PLATE FOR
CORRECT LINE VOLTAGE.
Connect electrical service to unit. Refer to unit wir-
ing diagram.
Power Wiring
For power supply connection, route field power wir-
ing L1 and L2 and connect either:
1. Unit Without EH: to field-provided and installed
disconnect switch and from switch to power
entry (unit side) and to unit power leads inside
the unit electrical section; or
2. Unit With EH: into the unit through power entry
(unit side) and then to the factory installed pow-
er switch inside the electrical section (see Fig-
ure 9). Note: power switch looks like a circuit
breaker but does not provide overload pro-
tection. Power switch provided only with elec-
tric heater (field kit or factory installed). NOTE:
When electric heat greater than 10kW is pro-
vided, two power supply circuits are required,
as shown on the wiring diagram.
Refer to nameplate or Electrical Ratings (page 28)
for FLA, maximum overcurrent protection device
(MOPD) and minimum circuit ampacity (MCA). Also
refer to wiring diagram affixed to unit to make con-
trol and power wiring connections. For new heater
installation, mark the nameplate label with the
matching heater kW rating. Label is located on the
exterior of the front top panel.
NOTE: Installer is responsible for power wiring and
branch circuit over current protection.
Control Voltage Wiring
Control voltage wiring may enter the unit at the con-
trol box located behind the blower access door, or
other convenient location. Control voltage wiring
DANGER
NEVER enter an enclosed fan cabinet or reach into
a unit while the fan is running.
LOCK OPEN AND TAG the fan motor power dis-
connect switch before working on a fan. Take fuses
with you and note removal on tag. Electric shock
can cause personal injury or death.
LOCK OPEN AND TAG the electric heat coil power
disconnect switch before working on or near heat-
ers.
Failure to follow these warnings could lead to per-
sonal injury or death.
DANGER
WARNING: Hazardous voltage. Only qualified
personnel must install the electrical service. Dis-
connect and Lock Out all incoming power sources
before connecting to electrical service.
WARNING: This appliance must be permanently
grounded in accordance with the National Electrical
Code and local code requirements.
WARNING: For use with copper conductors only.
INSTALLATION-ELECTRICAL
Figure 9
Unit with Electric Heat
CAUTION
Use only copper conductors for field-installed elec-
trical wiring. Unit terminals are not designed to
accept other types of conductors.
Do not allow wiring to touch the refrigerant tubing,
compressor, or any moving parts of the fan.
Make wiring connections in accordance with the
system wiring system diagram and these instruc-
tions. Wrong wiring may cause improper operation
or unit damage!
Unauthorized changes in the internal wiring can be
very dangerous. The manufacturer will accept no
responsibility for any damage or malfunction that
occurs as a result of such unauthorized changes.
leads exit the bottom of the control box and are
ready for field-connection.
CAUTION! To prevent malfunction of the air condi-
tioner caused by electrical noise, route control wiring
and inter-unit control wiring SEPARATELY FROM
THE POWER WIRING!
General
POWER
SWITCH

035-000051-002 Page 18 of 64 MMD IOM 1.3 8-15-2023
DANGER
WARNING: Hazardous voltage. Only qualified
personnel must install the electrical service. Dis-
connect and Lock Out all incoming power sources
before connecting to electrical service.
WARNING: This appliance must be permanently
grounded in accordance with the National Electrical
Code and local code requirements.
WARNING: For use with copper conductors only.
INSTALLATION-ELECTRICAL
Provide strain relief where field wiring passes
through cabinet. Wiring within the cabinet has
been positively located and supported so that it
does not pass over sharp metal edges or come in
contact with moving parts. After servicing, position
wiring properly in the original supports.
All field-installed wiring, including the electrical
ground, MUST comply with the National Electrical
Code (NEC) as well as applicable local codes. In
addition, all field wiring must conform to the Class
II temperature limitations described in the NEC.
Refer to factory wiring diagrams installed in the
unit. Use the MCA and MOPD from the nameplate
or electric heat nameplate or Electrical Ratings
(page 30) to size power supply wiring and overcur-
rent protection device. Installation must comply
with NEC and local codes.
For communicating controls, refer to electrical spe-
cific instructions, page 33-41. Refer to the con-
densing unit operation manual for more details.
CAUTION
Loose wiring may cause the terminal to overheat
or result in unit malfunction or cause a fire hazard.
Insure that all wiring is tightly connected!
Figure 9b
Unit with Electric Heat
POWER
SWITCH
Figure 9a
Unit without
Electric Heat
POWER
TERMINALS
EARTH
GROUND
WIRE
FIELD POWER
WIRES IN
THROUGH
CABINET SIDE
Figure 9c
Communications Wiring
COMM WIR-
ING IN
THROUGH
CABINET
SIDE, INTO
CONTROL
BOX
COMM
WIRING
OUT TO
TERMINAL
STRIP
FIELD POWER
WIRES IN
THROUGH
CABINET SIDE

035-000051-002 Page 19 of 64 MMD IOM 1.3 8-15-2023
INSTALLATION-ELECTRICAL (cont’d) TYPICAL WIRING DIAGRAM

035-000051-002 Page 20 of 64 MMD IOM 1.3 8-15-2023
INSTALLATION-ELECTRICAL (cont’d)
TYPICAL WIRING—ELECTRIC HEAT
TYPICAL WIRING DIAGRAMS—
Electric Heat: 1-6kW and 8-9.5kW
TYPICAL WIRING—ELECTRIC HEAT
3