Magic Aire DUC Series User manual

035-000050-001 1DUC IOM 1.2 5-9-2018
DUC Series Vertical FCU
Installation, Operation and Maintenance
Manual
VERTICAL
OPTION
HORIZONTAL
OPTION
Magic Aire DUC Series vertical fan coil units are direct drive High Efficiency air handlers delivering nominal
airflows of 600 to 2000 CFM and nominal cooling capacities of 1-1/2 to 5 tons.
Units may be specified with chilled water or DX cooling coils and hot water or electric heating coils to meet space
cooling loads or heating loads or both.

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Installaon, Start-Up
and Service
Instrucons
DUC Series Vertical FCU
Installation, Operation and Maintenance
Manual
Topic Page
SAFETY CONSIDERATIONS 5
PRODUCT NOMENCLATURE 6
ACCESSORIES 7
INSTALLATION 8
Pre-installation 8
Rigging 8
Service Clearances 9
Return Air & Unit Orientation 10
Unit Suspension or Floor Mount 13
Unpacking 12
Condensate Drain 12
Ductwork 13
Refrigerant Piping 13
Electric Heater Accessory 14-16
Electrical 17-18
Wiring Diagrams 19-23
START-UP 24
SERVICE 25-27
Fan & Fan Motor 25-26
Filters 27
Access Panels 27
Coil & Drain Pan Service 28
AIRFLOW DATA 29-35
ELECTRICAL RATINGS 36-37
DIMENSIONS 38-40
REFRIGERANT LEAKAGE WARNINGS 45
REPLACEMENT PARTS 41-45
STARTUP REPORT 46

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035-000050-001 5DUC IOM 1.2 5-9-2018
How to Use this Manual
This manual gives instructions regarding installation,
operation and maintenance for the DUC Series fan coil
unit. For more information refer to:
Catalog brochure for unit dimensions, options,
guide specifications and performance information.
New Magic 4 software for faster selection of new
equipment.
Website www.magicaire.com for replacement
parts guide, software downloads, product data and
contact info for your local Magic Aire representative.
Replacement Parts – Identify parts needed using
the replacement parts guide available at
www.magicaire.com.
Use these instructions in conjunction with other appro-
priate instructions, including but not limited to those in-
structions supplied with the outdoor unit (if applicable).
Installation must comply with all applicable local codes.
GENERAL
Installation and maintenance are to be performed only
by qualified personnel who are familiar with local codes
and regulations and are experienced with HVAC equip-
ment of this type.
WARNING: Sharp edges, coil surfaces and rotat-
ing fans are a potential injury hazard – avoid
contact.
WARNING: Hazardous voltage – Disconnect and
Lock Out all incoming power sources before ser-
vicing or installing unit. ELECTRIC SHOCK CAN
CAUSE DEATH.
WARNING: This equipment may be installed well
above finished floor—Use extreme caution when
working at heights.
SAFETY WARNING
Installer should pay particular attention to the following
words:
NOTE–intended to clarify or make installation 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.
UNPACKING-CHECK FOR DAMAGE!
Immediately inspect each unit for damage upon re-
ceipt.
1.Inspect units for external and concealed damage
immediately.
2.File any damage claims in accordance with Magic
Aire Freight Damage Policy and Terms and Condi-
tions (available at www.magicaire.com).
3.Do not repair damaged units without written authori-
zation.
4. Protect stored units from damage.
DANGER
Failure to torque impeller set screws properly may lead
to impeller failure and high velocity debris that is a le-
thal hazard!
Failure to rebalance wheel/motor after re-assembly
could result in unacceptable vibration, possibly leading
to impeller failure—lethal hazard!
Failure to follow these warnings could lead to personal
injury or death.
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 disconnect
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 dis-
connect switch before working on or near heaters.
Failure to follow these warnings could lead to personal
injury or death.
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 rig-
ging 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 remova-
ble panels on outdoor units when winds are strong or
gusting until you have sufficient help to control them.
Make sure panels are properly secured while repairs
are being made to a unit.
DO NOT remove access panel fasteners or open ac-
cess doors until fan is completely stopped. Pressure
developed by a moving fan can cause excessive force
against the panel which can injure personnel.
DO NOT work on dampers until their operators are dis-
connected.
BE SURE that fans are properly grounded before work-
ing on them.
Failure to follow these warnings could result in personal
injury or equipment damage.

035-000050-001 6DUC IOM 1.2 5-9-2018
PRODUCT NOMENCLATURE—ACCESSSORIES
Direct Drive
Generaon
Unit Size
1.5 through 5 Tons
(600 through 2000 CFM)
Primary Coil
3- or 4-Row CHW/2-Pipe or
Std Cap DX or High Cap DX
(single or dual circuit)
Secondary Coil
2-, 3-, or 4-Row HW or Electric
Heat, factory mounted.
Coil Treatment
Phenolic Coang
Motor & Voltage
Numerous motor selecons
including Single Phase standard
duty and ECM-VE single phase.
Drain Pan and Insulaon
Galvanized, Stainless Steel,
Universal
Foil Face Insulaon
Control Opons
Fan Control 24V, Mul-funcon
controllers
MODEL NOMENCLATURE
Position 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Example D U C 1 2 B 2 B S 5 B B A M
Return Air Cabinet Opons
Vercal and Horizontal
conguraons with Le,
Minor Design Revision
Standard Grade
Label
Use our New Magic 4 Selecon
Soware for:
 exact unit model selecon
 performance data
 submial informaon

035-000050-001 7DUC IOM 1.2 5-9-2018
PRODUCT NOMENCLATURE—ACCESSSORIES
Product Part Number Description
Product size
(H X W X D)
Package size
(H X W X D)
Weight
(Net)
Weight
(Gross)
Electric Heater 012-000458-100 1kW for sizes 06-20 6.7" X 11.0" X 22.5" 9" X 13" X 27" 4 lbs 6 lbs Electric Heater 012-000458-101 3kW for sizes 06-20 6.7" X 11.0" X 22.5" 9" X 13" X 27" 5 lbs 7 lbs Electric Heater 012-000458-102 5kW for sizes 06-20 6.7" X 11.0" X 22.5" 9" X 13" X 27" 5 lbs 7 lbs Electric Heater 012-000458-103 6kW for sizes 06-20 6.7" X 11.0" X 22.5" 9" X 13" X 27" 5 lbs 8 lbs Electric Heater 012-000458-104 8kW for sizes 06-20 6.7" X 11.0" X 22.5" 9" X 13" X 27" 6 lbs 8 lbs Electric Heater 012-000458-105 9.5kW for sizes 06-20 6.7" X 11.0" X 22.5" 9" X 13" X 27" 6 lbs 8 lbs Electric Heater 012-000458-106 14.5kW for sizes 10-20 6.7" X 11.0" X 22.5" 9" X 13" X 27" 7 lbs 9 lbs Electric Heater 012-000458-107 19.5kW for sizes 14-20 6.7" X 11.0" X 22.5" 9" X 13" X 27" 7 lbs 9 lbs Plenum Chamber contact factory For 06-08 Model, with 2" Filter, Single Pkg 20.2" X 17.5" X 22.2" 22" X 23" X 28" 36 lbs 43 lbs Plenum Chamber contact factory For 10-12 Model, with 2" Filter, Single Pkg 20.2" X 20.0" X 25.2" 22" X 26" X 31" 41 lbs 49 lbs Plenum Chamber contact factory For 14-16 Model, with 2" Filter, Single Pkg 24.2" X 22.0" X 27.2" 26" X 28" X 33" 49 lbs 59 lbs Plenum Chamber contact factory For 20 Model, with 2" Filter, Single Pkg 24.2" X 24.0" X 31.2" 26" X 30" X 37" 60 lbs 71 lbs Filter Box contact factory For 06-08 Model, 2" MERV 8 Filter 4" X 17.5" X 22.2" 8" X 21" X 26" 12 lbs 15 lbs Filter Box contact factory For 10-12 Model, 2" MERV 8 Filter 4" X 20.0" X 25.2" 8" X 23" X 29" 14 lbs 18 lbs Filter Box contact factory For 14-16 Model, 2" MERV 8 Filter 4" X 22.0" X 27.2" 8" X 25" X 31" 15 lbs 19 lbs Filter Box contact factory For 20 Model, 2" MERV 8 Filter 4" X 24.0" X 31.2" 8" X 27" X 35" 20 lbs 25 lbs
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.

035-000050-001 8DUC IOM 1.2 5-9-2018
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 over-
flow.
The International Mechanical Code (IMC) section
307.2.3 requires the use of auxiliary drain pans. Many
municipalities have adopted this code.
Magic Aire holds that this practice represents the stand-
ard for professional installation whether or not this code
has been adopted in a specific municipality or territory.
As such, water damages that would have been prevent-
ed had an auxiliary pan been deployed will not be con-
sidered for compensation. This position is taken regard-
less of whether the source of the moisture was specified
as a potential 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. Professional installers recognize the
value of protecting customer assets against foreseeable
events. Customers who choose to avoid the cost of com-
mon protective measures waive their right to seek dam-
ages when those foreseeable events occur. If the prod-
uct 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
overflow which may result from clogged drains or from
other reasons. Provide proper drain piping for this auxil-
iary pan. Consult local codes for additional precautions
before installation.
PREINSTALLATION
1. Check items received against packing list.
2. Do not stack unit components or accessories during
storage. Stacking can cause damage or defor-
mation.
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 reasonably
level and sturdy to prevent undue stress or per-
manent damage to the unit structure or compo-
nents. 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, enter fan
section through access door or through fan in-
let, 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 applicable to lift unit. Do not
lift unit by coil connections or headers.
1. Do not remove protective caps from coil piping con-
nections until ready to connect piping.
2. Do not remove protective cover or grease from fan
shaft until ready to install sheave.
3. Lay rigid temporary protection such as plywood
walkways in unit to prevent damage to insulation or
bottom panel during installation.
Fig. 1 and 2
Horizontal and Vertical Fan Coil Units with Second-
ary (Auxiliary) Drain Pans
Provide the secondary pan with it’s own water flow sen-
sor along with piping to a safe location where drainage
will visually indicate the error condition. Vertical installa-
tion must be below the ducted return (if present).
INSTALLATION
Fig. 1
Fig. 2
(FIELD-PROVIDED)
(FIELD-PROVIDED)

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INSTALLATION—SERVICE CLEARANCES
NOTES:
1. BLOWER SERVICE REQUIRES FRONT ACCESS
ONLY.
2. RECOMMENDED BUT NOT NECESSARY: AL-
LOW 12” ON RIGHT AND LEFT SIDES FOR SIG-
NIFICANT BUT INFREQUENT SERVICE PROCE-
DURES SUCH AS DRAIN PAN OR COIL RE-
PLACEMENT.
A B C D E F
06/08 36.0 36.0 36.0 22.0 6.0 9.0
10/12 36.0 36.0 36.0 25.0 6.0 10.0
14/16 36.0 36.0 36.0 27.0 6.0 11.0
20 36.0 36.0 36.0 31.0 6.0 11.0
G H L M N
06/08 12.0 7.0 19.4 35.7 45.0
10/12 12.0 7.0 23.5 40.6 50.0
14/16 12.0 7.0 26.3 43.6 54.0
20 12.0 7.0 28.3 46.4 56.0
UNIT
SIZE
CLEARANCE DIMENSION
(INCHES)
3. WHEN UNIT IS INSTALLED HORIZONTALLY
(LYING ON RIGHT OR LEFT SIDE), CLEARANC-
ES REMAIN THE SAME AS INDICATED ABOVE,
EXCEPT TRAP CLEARANCE EXTENDS BELOW
THE UNIT. NOTES:

035-000050-001 10 DUC IOM 1.2 5-9-2018
Cabinet and Drain Pan Configurations
Notes:
1. Return Air Cabinet is model digit 12; drain pan is digit 13.
Refer to New Magic 4 soware for selecons and perfor-
mance.
2. All drain pans have front condensate drain connecons
(primary and auxiliary), and so are RH or LH, not both.

035-000050-001 11 DUC IOM 1.2 5-9-2018
Vertical Only to Vertical/Horizontal Right Configura-
tion
Note: This is a reference for a single type of conver-
sion. Contact factory for instructions regarding your
configuration change
1. Remove filter door and filter
2. Remove blower access panel
3. Remove coil panels
4. Remove coil support screws to loosen coil from left
side panel (top of coil, left side of unit cabinet)
5. Remove drain pan support screws to loosen drain
pan from right side panel (bottom of coil, right side
of unit cabinet)
6. Carefully remove coil/drainpan assembly
7. Separate coil from vertical-only drain pan (2
screws)
8. Separate coil from coil support (2 screws)
9. Relocate coil blockoff to the other side of the coil (2
prestole clips)
10. 10. Relocate coil support to the other side of the
coil (2 screws)
11. Attach coil to new extended drain pan (2
screws): condensate drain connections are at the
front. Coil angles from lower right to upper left. Suc-
tion line is on the entering air side of the coil
(towards the filter). Coil support is at the top.
12. Install the extended drain pan support to the right
side panel (4 screws at bottom) with the sheet metal
break pointing towards filter area.
13. Carefully install the coil/drainpan assembly into the
unit.
14. Attach drainpan to right cabinet side, 4 screws at top
of pan.
15. Attach coil support to left cabinet side, 4 screws.
16. Install new DX coil panels
17. Re-install filter and filter door
18. Re-install blower access panel
19. Return unit to service.
INSTALLATION—Configuration Conversion
Parts required:
Qty Part Number Description
1ea 076-002644-000 DRAIN PAN ASSY RH DRAIN MVA24
1ea 076-002851-000 DRAINPAN SUPPORT MVA18/24
1ea 016-000269-000 INSL DRAIN PAN DUC06/08 DB
1ea 076-006154-001 PANEL,COIL DX UPPER DUC0608 RH
1ea 076-006158-001 PANEL,COIL DX LOWER DUC0608 RH

035-000050-001 12 DUC IOM 1.2 5-9-2018
Figure 3a
CEILING SUSPENSION DETAILS
ITEM NO. DESCRIPTION QTY.
1DUC AIR HANDLER 1
2UNISTRUT, 1-5/8 X 1-5/8, 16 GA MIN, 9/16" DIA HOLES OR EQUIV 2
3ALL THREAD 3/8" NOM, ASTM A307-GR A OR EQUIV 4
4FLAT WASHER USS, 3/8" NOM, ANSI B18.22.1 8
5LOCK WASHER, 3/8" NOM, ANSI B18.21.1 8
6HEX NUT, 3/8"-16 UNC, ASTM A563-GR A OR EQUIV 8
7GASKET TAPE, RUBBER OR EQUIV 2
NOTE:
1. RIGHT HORIZONTAL AIRFLOW
CONFIGURATION SHOWN. SIMILAR
FOR LEFT HORIZONTAL CONFIGU-
RATION.
RIGHT HAND VIEW
FRONT VIEW
ISOMETRIC VIEW

035-000050-001 13 DUC IOM 1.2 5-9-2018
INSTALLATION
Unpacking
1. Remove all packaging and any foreign material 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 configurations
depending on the return air configuration selected—
see Figure 1.
NOTE: Right and left return units are not recom-
mended 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 struc-
ture.
Unit Support
Floor mounting: Unit may be mounted on a house-
keeping pad, floor, platform or plenum. Provide a suit-
able isolation pad to minimize sound transmission to
the structure.
CAUTION! Make sure to allow enough elevation to
permit construction of the condensate trap. Also
allow enough elevation and clearance for opening
the filter door (removes to the front). See Service
Clearances.
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).
Ceiling Suspension: Mount the unit in ceiling-
suspended horizontal orientation per suspension de-
tails (Figure 4a). Unit is NOT intended to be wall
mounted. Consult a qualified structural engineer for
special mounting considerations.
Install the unit so that it pitches slightly –(1/8 inch) –
toward the condensate drain connection.
Condensate Drain
Install a trapped condensate drain line at unit drain
connection. All DUC units have 3/4 in. FPT conden-
sate main and auxiliary drain connections.
Provide adequate trap clearance (trap depth) be-
neath the unit as indicated in Fig. 4a. Provide freeze-
protection as required to insure reliable condensate
drainage. Freeze protection measures are customer-
supplied and installed.
Pipe to condensate drain using PVC or copper or
other suitable material. Pitch drain piping downward
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 aux-
iliary drain.
WARNING
INSURE THAT THE UNIT IS ADEQUATELY SUP-
PORTED FROM STRUCTURE TO PREVENT DAM-
AGE OR INJURY CAUSED BY FALLING EQUIP-
MENT!
If uncertain about how to connect to the struc-
ture, consult a qualified structural engineer.
Placing Unit In Ductwork
1. Utilize flexible transitions on supply and return con-
nections to reduce noise and vibration transmission
to the structure.
2. When the connecting return air duct is smaller than
the coil inlet opening, construct the transition piece
so that the vertical and horizontal dimensions 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 pre-
ceding the unit inlet.
Duct Insulation and Vapor Proofing:
Properly select and install duct insulation as re-
quired by the application.
All externally insulated duct work must have an ade-
quate vapor seal for summer operation. This is par-
ticularly important where the duct is exposed 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 insulating material and subse-
quent loss of its insulating value.
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 CON-
DENSATE DRAIN PIPING.
3. AVOID BLOCKING FILTER SERVICE ACCESS WHEN INSTALLING CON-
DENSATE DRAIN PIPING.
Fig. 4A — Condensate Drain
NOT TO SCALE

035-000050-001 14 DUC IOM 1.2 5-9-2018
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 connec-
tions through the front of the cabinet.
CAUTION: Use proper care when brazing including
use of heat sink (wet cloth or other method) to pre-
vent damage to liquid line and suction line compo-
nents (see Figure 4b)
Size and install refrigerant lines in accordance with
the condensing unit manufacturer’s instructions. Pro-
vide insulation on the suction line, to prevent conden-
sation. Provide insulation on the liquid line if unit to
be used for heat pump service or if otherwise re-
quired.
PIPING — Direct expansion, chilled water, and hot wa-
ter coils should always be piped for counterflow. (Fluid
should enter the coil at the leaving-air side.) Steam coils
must have the condensate connection at bottom of coil.
Fig. 4b — Connection of Refrigerant
Piping—Brazing Details
Wrap AHU-side
piping with wet cloth
before brazing
Apply brazing to
full circumference
Chilled Water and Hot Water Coil Piping — Size
chilled water and hot water piping to deliver desired
pressure drop and flow rate. Install control valves as
required to allow temperature control system to control
the water flow. Provide all require service valves and
unions to make piping system serviceable. Provide cir-
cuit setter to allow balancing of water flow.
The following features are not required but are strongly
recommended:
Provide pressure/temperature ports on supply and re-
turn side piping to allow differential pressure measure-
ment.
Provide autoflow control valves to automatically provide
correct water flow rate across a wide range of supply/
return differential pressures (saves energy!)
Insulate all water piping to prevent condensation (chilled
water piping) and energy loss (hot water and chilled wa-
ter piping). Size and select insulation material to match
the project specifications.

035-000050-001 15 DUC IOM 1.2 5-9-2018
INSTALLATION—ELECTRIC HEAT
Electric Heater Accessory
The electric heater may be factory-installed or field-
installed. See Figures 5 through 8.
Removal Procedure:
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 heat-
DANGER
WARNING: Hazardous voltage. Only qualified per-
sonnel must install the electrical service. Disconnect
and Lock Out all incoming power sources before con-
necting 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)

035-000050-001 16 DUC IOM 1.2 5-9-2018
INSTALLATION—ELECTRIC HEAT
Install Procedure:
To install the electric heater,
1. Disconnect and lock out electrical power from the
unit. Remove heater access panel. Disconnect
field power wires from the unit power wires.--
DANGER! MAKE SURE there is no voltage sup-
ply 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 switch-
es).
4. Remove plate on the heater bulkhead (4 screws).
5. Install heater by carefully supporting the heater and
inserting it into the opening in the heater bulkhead.
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.
6. Connect 2 wiring harnesses (male) to the matching
female receptacles in the blower deck.
DANGER
WARNING: Hazardous voltage. Only qualified per-
sonnel must install the electrical service. Disconnect
and Lock Out all incoming power sources before con-
necting to electrical service.
7. Connect field wiring to the breaker-style power
switches on the front of the heater.——--
WARNING! Be sure to provide the appropriate
wire size and branch circuit protection as re-
quired by the unit nameplate!
8. Install the heater access panel.
9. 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.
10. Mark the nameplate label with the matching heater
kW rating. Label is located on the exterior of the
front top panel.
Fig. 8A — Heater Accessory Installed
PIN
HEATER SHROUD
Fig. 8B — Heater Accessory Installed
Fig. 8
Accessory Removal
(right side and heater access panels not shown for clarity)
RIGHT SIDE

035-000050-001 17 DUC IOM 1.2 5-9-2018
INSTALLATION—ELECTRIC HEAT
Electric Heater Accessory-DUC size 06 and 08
The electric heater must be adjusted to fit unit sizes 1
-ton, 1.5-ton and 2-ton unit models, See Figures 9a
through 9d.
Switch Plate Adjustment Procedure:
To adjust the switch plate to shorten the heater
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 per-
sonnel must install the electrical service. Disconnect
and Lock Out all incoming power sources before con-
necting to electrical service.
Fig. 9b
Heater—Long
Format
(Bottom view;
mounting screws
shown by circles)
Fig. 9c
Heater—Short
Format
(Bottom view;
mounting screws
shown by circles)
Fig. 9a — Heater—Long Format
(mounting screws shown by circles)
Fig. 9d
Heater—Short Format
(mounting screws shown by circles)
SWITCH
PLATE
HEATER
PLATE

035-000050-001 18 DUC IOM 1.2 5-9-2018
INSTALLATION—ELECTRICAL
DANGER
WARNING: Hazardous voltage. Only qualified per-
sonnel must install the electrical service. Disconnect
and Lock Out all incoming power sources before con-
necting 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.
Typical wiring diagrams are shown on the following pag-
es FOR REFERENCE. Always refer to the wiring dia-
gram on the air handling unit for actual wiring.
NOTE: CHECK MOTOR RATING PLATE FOR COR-
RECT LINE VOLTAGE.
Connect electrical service to unit. Refer to unit wiring
diagram.
Power Wiring
For power supply connection, route field power wiring L1
and L2 and connect either:
1. Unit Without EH: to field-provided and installed dis-
connect switch and from switch to power entry (unit
side) and to unit power leads inside the unit electri-
cal section; or
2. Unit With EH: into the unit through power entry (unit
side) and then to the factory installed power switch
inside the electrical section (see Figure 9). Note:
power switch looks like a circuit breaker but does
not provide overload protection. Power switch
provided only with electric heater (field kit or factory
installed). NOTE: When electric heat greater than
10kW is provided, two power supply circuits are re-
quired, 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 wir-
ing diagram affixed to unit to make control 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 control
box located behind the blower access door, or other
convenient location. Control voltage wiring leads exit
the bottom of the control box and are ready for field-
connection.
CAUTION! To prevent malfunction of the air conditioner
caused by electrical noise, route control wiring SEPA-
RATELY FROM THE POWER WIRING!
General
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 orig-
inal 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
POWER
SWITCH
Figure 10
Unit with Electric Heat
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 discon-
nect 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 dis-
connect switch before working on or near heaters.
Failure to follow these warnings could lead to personal
injury or death.
CAUTION
Use only copper conductors for field-installed electrical
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 instructions. 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.

035-000050-001 19 DUC IOM 1.2 5-9-2018
wiring must conform to the Class II temperature limita-
tions 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 35) to size
power supply wiring and overcurrent protection device.
Installation must comply with NEC and local codes.
Refer to the condensing unit operation manual for more
details.
INSTALLATION—ELECTRICAL
DANGER
WARNING: Hazardous voltage. Only qualified per-
sonnel must install the electrical service. Disconnect
and Lock Out all incoming power sources before con-
necting 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.
CAUTION
Loose wiring may cause the terminal to overheat or re-
sult in unit malfunction or cause a fire hazard. Insure
that all wiring is tightly connected!
Figure 11b
Unit with Electric Heat
FIELD POWER WIRES IN
THROUGH CABINET SIDE
FIELD POWER
WIRES IN
THROUGH
CABINET SIDE EARTH
GROUND
POWER
TERMINALS
Figure 11a
Unit without Electric Heat

035-000050-001 20 DUC IOM 1.2 5-9-2018
INSTALLATION—WIRING DIAGRAMS
TYPICAL WIRING DIAGRAMS
115V, and 208/240V
TYPICAL WIRING DIAGRAM - 115V
TYPICAL WIRING DIAGRAM - 208/240V