Carrier 50KC04 User manual

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53500239-01 Printed in U.S.A. Form 50KC-4-6-03SI Pg 1 3-2020 Replaces: 50KC-4-6-02SI
Installation Instructions
NOTE: Read the entire instruction manual before starting the
installation.
CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 1
Model Number Nomenclature and Dimensions . . . . 2
Rated Indoor Airflow (cfm) . . . . . . . . . . . . . . . . . . . . . 2
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Jobsite Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Step 1 — Plan for Unit Location . . . . . . . . . . . . . . . 10
• ROOF MOUNT
Step 2 — Plan for Sequence of Unit Installation . . 10
• CURB-MOUNTED INSTALLATION
• PAD-MOUNTED INSTALLATION
• FRAME-MOUNTED INSTALLATION
Step 3 — Inspect Unit . . . . . . . . . . . . . . . . . . . . . . . . 10
Step 4 — Provide Unit Support . . . . . . . . . . . . . . . . 10
• ROOF CURB MOUNT
• SLAB MOUNT (HORIZONTAL UNITS ONLY)
• ALTERNATE UNIT SUPPORT (IN LIEU OF CURB OR
SLAB MOUNT)
Step 5 — Field Fabricate Ductwork . . . . . . . . . . . . . 11
• FOR UNITS WITH ACCESSORY ELECTRIC HEATERS
Step 6 — Rig and Place Unit . . . . . . . . . . . . . . . . . . 11
• POSITIONING ON CURB
Step 7 — Convert to Horizontal and Connect
Ductwork (when required) . . . . . . . . . . . . . . . . . . 12
Step 8 — Install Outside Air Hood . . . . . . . . . . . . . . 13
• ECONOMIZER HOOD PACKAGE REMOVAL AND
SETUP - FACTORY OPTION
• ECONOMIZER HOOD ASSEMBLY
Step 9 — Units with Hinged Panels Only . . . . . . . . 14
Step 10 — Install External Condensate Trap
and Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Step 11 — Make Electrical Connections . . . . . . . . . 15
• FIELD POWER SUPPLY
• UNITS WITH FACTORY-INSTALLED NON-FUSED
DISCONNECT
• UNITS WITHOUT FACTORY-INSTALLED NON-
FUSED DISCONNECT
• ALL UNITS
• CONVENIENCE OUTLETS
• FACTORY OPTION THRU-BASE CONNECTIONS
• UNITS WITHOUT THRU-BASE CONNECTIONS
• FIELD CONTROL WIRING
• THERMOSTAT
• UNIT WITHOUT THRU-BASE CONNECTION KIT
• HEAT ANTICIPATOR SETTINGS
Electric Heaters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
• SINGLE POINT BOXES AND SUPPLEMENTARY
FUSES
• SINGLE POINT BOXES WITHOUT FUSES
• LOW-VOLTAGE CONTROL CONNECTIONS
Humidi-MiZer® Control Connections . . . . . . . . . . . 21
• HUMIDI-MIZER – SPACE RH CONTROLLER
Economi$er® X (Factory Option) . . . . . . . . . . . . . . .23
• SYSTEM COMPONENTS
• SPECIFICATIONS
• INPUTS
• OUTPUTS
• ENVIRONMENTAL
• ECONOMIZER MODULE WIRING DETAILS
• INTERFACE OVERVIEW
• SETUP AND CONFIGURATION
• ENTHALPY SETTINGS
• CHECKOUT
• TROUBLESHOOTING
Control and Power Wiring Diagrams . . . . . . . . . . . .34
Smoke Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
• ADDITIONAL APPLICATION DATA
PremierLink™ Controller (Factory Option) . . . . . . .42
RTU Open Controller (Factory-installed Option) . .42
Controller Options . . . . . . . . . . . . . . . . . . . . . . . . . . .42
• LOW AMBIENT
Step 12 — Adjust Factory-Installed Options . . . . . .43
• SMOKE DETECTORS
• ECONOMI$ER IV OCCUPANCY SWITCH
Step 13 — Install Accessories . . . . . . . . . . . . . . . . .43
Step 14 — Check Belt Tension . . . . . . . . . . . . . . . . .43
• BELT FORCE — DEFLECTION METHOD
• BELT TENSION METHOD
Evaporator Coil Metering Devices . . . . . . . . . . . . . .44
Pre-Start and Start-Up . . . . . . . . . . . . . . . . . . . . . . . .44
UNIT START-UP CHECKLIST. . . . . . . . . . . . . . . . CL-1
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment can be
hazardous due to system pressure and electrical components. Only
trained and qualified service personnel should install, repair, or
service air-conditioning equipment.
Untrained personnel can perform basic maintenance functions of
cleaning coils and filters and replacing filters. All other operations
should be performed by trained service personnel. When working
on air-conditioning equipment, observe precautions in the
literature, tags and labels attached to the unit, and other safety
precautions that may apply.
Follow all safety codes, including ANSI (American National
Standards Institute) Z223.1. Wear safety glasses and work gloves.
Use quenching cloth for unbrazing operations. Have fire
extinguisher available for all brazing operations.
It is important to recognize safety information. This is the safety-
alert symbol . When you see this symbol on the unit and in
instructions or manuals, be alert to the potential for personal
injury.
Understand the signal words DANGER, WARNING, CAUTION,
and NOTE. These words are used with the safety-alert symbol.
DANGER identifies the most serious hazards which will result in
severe personal injury or death. WARNING signifies hazards
which could result in personal injury or death. CAUTION is used
to identify unsafe practices, which may result in minor personal
injury or product and property damage. NOTE is used to highlight
50KC04-06
Single Package Rooftop Cooling Only
with Puron®(R-410A) Refrigerant

2
suggestions which will result in enhanced installation, reliability,
or operation.
Model Number Nomenclature and Dimensions
See Fig. 1 for 50KC model number nomenclature. See Fig. 2 and
3 for unit dimensional drawings. Figure 4 shows service clearance
dimensions; Fig. 5 shows base rail details; Fig. 6 shows thru-the-
base charts; and Fig. 7 shows roof curb details.
Rated Indoor Airflow (cfm)
Table 1 lists the rated indoor airflow used for the AHRI efficiency
rating for the units covered in this document.
Table 1 — Rated Indoor Index (cfm)
DANGER
ELECTRICAL SHOCK HAZARD
Failure to follow this warning will result in personal injury or
death.
Before performing service or maintenance operations on unit,
turn off main power switch to unit and install lock(s) and lock-
out tag(s). Ensure electrical service to rooftop unit agrees with
voltage and amperage listed on the unit rating plate. Unit may
have more than one power switch.
WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
R-410A refrigerant systems operate at higher pressures than
standard R-22 systems. Do not use R-22 service equipment or
components on R-410A refrigerant equipment.
WARNING
PERSONAL INJURY AND ENVIRONMENTAL
HAZARD
Failure to follow this warning could cause personal injury or
death.
Relieve pressure and recover all refrigerant before system re-
pair or final unit disposal.
Wear safety glasses and gloves when handling refrigerants.
Keep torches and other ignition sources away from refriger-
ants and oils.
CAUTION
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care and
wear appropriate protective clothing, safety glasses and gloves
when handling parts and servicing air conditioning equipment.
MODEL NUMBER RATED INDOOR AIRFLOW (cfm)
50KC*A/B04 1050
50KC*A/B05 1400
50KC*A/B06 1750

3
Fig. 1 — 50KC 04-06 Model Number Nomenclature (Example)
Coil Options (outdoor-indoor-hail guard
A = Al/Cu - Al/Cu
B = Precoat Al/Cu - Al/Cu
C = E-coat Al/Cu - Al/Cu
D = E-coat Al/Cu - E-coat Al/Cu
E = Cu/Cu - Al/Cu
F = Cu/Cu - Cu/Cu
M = Al/Cu - Al/Cu – Louvered Hail Guards
N = Precoat Al/Cu - Al/Cu – Louvered Hail Guards
P = E-coat Al/Cu - Al/Cu – Louvered Hail Guards
Q = E-coat Al/Cu - E-coat Al/Cu – Louvered Hail Guards
R = Cu/Cu - Al/Cu – Louvered Hail Guards
S = Cu/Cu - Cu/Cu – Louvered Hail Guards
5 0 K C - A 0 4 A 0 A 5 - 0 A 0 A 0
Unit Heat Type
50 – Cooling with Electric
Heat
Series/Model
KC – 14 SEER Efficiency
Refrig. Systems Options
A – Standard One Stage Cooling Models
B – Standard One Stage Cooling Models
with Humidi-MiZer System
Cooling Tons
04 - 3 ton
05 - 4 ton
06 - 5 ton
Packaging and Seismic Compliant
0 = Standard
1 = LTL
Electrical Options
A = None
C = Non-Fused Disconnect
D = Thru-The-Base Connections
F = Non-Fused Disconnect and Thru-The-Base
Connections
Service Options
0 = None
1 = Unpowered Convenience Outlet
2 = Powered Convenience Outlet
3 = Hinged Panels
4 = Hinged Panels, Unpowered Convenience Outlet
5 = Hinged Panels, Powered Convenience Outlet
Intake / Exhaust Options
A = None
B = Temperature Economizer w/ Barometric Relief
F = Enthalpy Economizer w/ Barometric Relief
K = 2-Position Damper
U = Temp Ultra Low Leak Economizer w/Baro Relief
W = Enthalpy Ultra Low Leak Econo w/Baro Relief
Base unit controls
0 = Electro-mechanical Controls Can be used with W7212
EconoMi$er IV (Non – Fault Detection and Diagnostic)
1 = PremierLink Controller
2 = RTU Open Multi-Protocol Controller
6 = Electro-mechanical - Can be used with W7220 EconoMi$er X
(with Fault Detection and Diagnostic)
Sensor Options
A = None
B = RA Smoke Detector
C = SA Smoke Detector
D = RA + SA Smoke Detector
E = CO
2
F = RA Smoke Detector and CO
2
G = SA Smoke Detector and CO
2
H = RA + SA Smoke Detector and CO
2
J = Condensate Overflow Switch (electro mech controls only)
K = Condensate Overflow Switch and RA Smoke Detectors
L = Condensate Overflow Switch and RA and SA Smoke
Detectors
Indoor Fan Options
0 = Direct Drive X13 Motor
2 = Medium Static Option – Belt Drive
3 = High Static Option – Belt Drive
Design Revision
Factory Assigned
Voltage
1 = 575/3/60 5 = 208-230/3/60
3 = 208-230/1/60 6 = 460/3/60
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
NOTE:: On single phase (-3 voltage code) models, the following
are not available as a factory installed option:
-
- Coated Coils or Cu Fin Coils
- Louvered Hail Guards
- Economizer or 2 Position Damper
- Powered 115 Volt Convenience Outlet
Not all possible options can be displayed above.
Heat Size
- - No Heat
)
Humidi-MiZer System

4
Fig. 2 — Unit Dimensional Drawing of Units Built On and After 4/15/19

5
Fig. 3 — Unit Dimensional Drawing of Units Built on and Prior to 4/15/19

6
Fig. 4 — Unit Corner Weights and Clearances

7
Fig. 5 — Base Rail Details

8
Fig. 6 — Thru-the-Base Charts

9
Fig. 7 — Roof Curb Details
EE
7/16"
[11]
4 9/16"
[115.5]
1/4"
[7.0]
5' 7-3/8"
[1711.3]
1' 4-13/16"
[427] INSIDE
1-3/4"
[44.4]
2-3/8"
[61]
1-3/4"
[44.5]
1.00"
[25.4]
"A"
1-3/4"
[44.4]
21.74"
[552.2]
5.42"
[137.7]
11.96"
[303.8]
4.96"
[126.0] 70.87"
[1800.2]
40.69"
[1033.5]
21.84"
[554.7]
16.03"
[407.2]
1.75"
[44.5] 20.41"
[518.3]
3.00"
[76.2]
13.78"
[350.0]
14.00"
[355.6]
3.00"
[76.2]
15.19"
[385.8]
32.19"
[817.6]
3'-1 3/16"
[944.6]
"A"
1-3/4"
[44.5]
CRBTMPWR001A01 3/4" [19] NPT
3/4" [19] NPT
1/2" [12.7] NPTCRRFCURB002A01
CONNECTOR PKG. ACC. GAS CONNECTION TYPE GAS FITTING POWER WIRING
FITTING
CONTROL WIRING
FITTING
ACCESSORY CONVENIENCE
OUTLET WIRING CONNECTOR
THRU THE CURB
1/2" [12.7] NPT 1/2" [12.7] NPT
CRBTMPWR003A01 THRU THE BOTTOM
ROOF CURB
ACCESSORY # A
CRRFCURB001A01 14"
[356]
24"
[610]
ECN NO.APP'DCHK'DBYDATEREVISION RECORDREV
1067898--MMC04/22/13
OVERALL DIM. 5'-7 3/8" WAS 5'-7 7/8; 18GA
MATERIAL WA 16 GA.; NAIL FIELD SUPPLIED WAS
WITH CURB
A
DRAWING RELEASE LEVEL: PRODUCTION
THIRD ANGLE
PROJECTION
UNLESS OTHERWISE SPECIFIED
DIMENSIONS ARE IN INCHES
TOLERANCES ON: THIS DOCUMENT AND THE INFORMATION CONTAINED THEREIN
IS PROPRIETARY TO CARRIER CORPORATION AND SHALL NOT
BE USED OR DISCLOSED TO OTHERS, IN WHOLE OR IN PART,
WITHOUT THE WRITTEN AUTHORIZATION OF CARRIER CORPORATION.
1 DEC 2 DEC 3 DEC ANG
MATERIAL ----
-
-
-
AUTHORIZATION NUMBER TITLE
1041738
CURB ASY, ROOF
ENGINEERING MANUFACTURING (004-007)
ENGINEERING REQUIREMENTS ----SIZE DRAWING NUMBER REV
T-005, Y-002 DRAFTER CHECKER D
48TC400427 B
WEIGHT: -MMC 06/17/11 - - SHEET 5 OF 5
SURFACE FINISH MFG/PURCH MODEL (INTERNAL USE ONLY) NEXT DRAWING SCALE DISTRIBUTION
- PURCH - N/A MMC
NOTES:
1. ROOFCURB ACCESSORY IS SHIPPED DISASSEMBLED.
2. INSULATED PANELS: 25.4 [1"] THK. POLYURETHANE FOAM, 44.5 [1-3/4] # DENSITY.
3. DIMENSIONS IN [ ] ARE IN MILLIMETERS.
4. ROOFCURB: 18 GAGE STEEL.
5. ATTACH DUCTWORK TO CURB. (FLANGES OF DUCT REST ON CURB).
6. SERVICE CLEARANCE 4 FEET ON EACH SIDE.
7. DIRECTION OF AIR FLOW.
8. CONNECTOR PACKAGE CRBTMPWR001A01 IS FOR THRU-THE-CURB GAS TYPE
PACKAGE CRBTMPWR003A01 IS FOR THRU-THE-BOTTOM TYPE GAS CONNECTIONS.
TYPICAL (4) SIDES
SUPPLY AIR RETURN AIR
ROOFING MATERIAL
(FIELD SUPPLIED)
CANT STRIP
(FIELD SUPPLIED)
ROOFING FELT
(FIELD SUPPLIED)
COUNTER FLASHING
(FIELD SUPPLIED)
UNIT
GASKET
(SUPPLIED WITH CURB)
RIGID INSULATION
(FIELD SUPPLIED)
DUCT
(FIELD SUPPLIED)
NAIL (FIELD SUPPLIED)
CERTIFIED DRAWING
VIEW "B"
CORNER DETAIL
SEE VIEW "B"
RETURN AIR
SUPPLY AIR
SUPPLY AIR
OPENING
RETURN AIR
OPENING
GAS SERVICE PLATE
THRU THE CURB
DRILL HOLE
2" [50.8] @
ASSEMBLY (IF
REQUIRED)
(SEE NOTE #8)
SEE NOTE #2
11 3/4"[298.5] WIDE
INSULATED DECK PANELS
8 9/16"[217.5] WIDE
INSULATED DECK PANEL
1/3/4"[44.5]
SCALE 0.250
E-ESECTION

10
INSTALLATION
Jobsite Survey
Complete the following checks before installation:
1. Consult local building codes and the NEC (National Electri-
cal Code) ANSI/NFPA 70 for special installation require-
ments.
2. Determine unit location (from project plans) or select unit
location.
3. Check for possible overhead obstructions which may inter-
fere with unit lifting or rigging.
Step 1 — Plan for Unit Location
NOTE: Select a location for the unit and its support system (curb
or other) that provides for minimum clearances required for safety
(including clearance to combustible surfaces), unit performance
and service access below, around and above unit as specified in
unit drawings. See Fig. 4. Consider also the effect of adjacent
units.
Unit may be installed directly on wood flooring or on Class A, B,
or C roof-covering material when roof curb is used. Do not install
unit in an indoor location. Do not locate air inlets near exhaust
vents or other sources of contaminated air.
Although unit is weatherproof, avoid locations that permit water
from higher level runoff and overhangs to fall onto unit.
Select a unit mounting system that provides adequate height to al-
low installation of condensate trap per requirements. Refer to Step
10 — Install External Condensate Trap and Line – for required
trap dimensions.
ROOF MOUNT
Check building codes for weight distribution requirements. Unit
operating weight is shown in Table 2.
Step 2 — Plan for Sequence of Unit Installation
The support method used for this unit will dictate different se-
quences for the steps of unit installation. For example, on curb-
mounted units, some accessories must be installed on the unit be-
fore the unit is placed on the curb. Review the following for rec-
ommended sequences for installation steps.
CURB-MOUNTED INSTALLATION
1. Install curb
2. Install field-fabricated ductwork inside curb
3. Install accessory thru-base service connection package
(affects curb and unit) (refer to accessory installation instruc-
tions for details)
4. Prepare bottom condensate drain connection to suit planned
condensate line routing (refer to Step 10 for details)
5. Rig and place unit
6. Install outdoor air hood
7. Install condensate line trap and piping
8. Make electrical connections
9. Install other accessories
PAD-MOUNTED INSTALLATION
1. Prepare pad and unit supports
2. Check and tighten the bottom condensate drain connection
plug
3. Rig and place unit
4. Convert unit to side duct connection arrangement
5. Install field-fabricated ductwork at unit duct openings
6. Install outdoor air hood
7. Install condensate line trap and piping
8. Make electrical connections
9. Install other accessories
FRAME-MOUNTED INSTALLATION
Frame-mounted applications generally follow the sequence for a
curb installation. Adapt as required to suit specific installation
plan.
Step 3 — Inspect Unit
Inspect unit for transportation damage. File any claim with trans-
portation agency.
Confirm before installation of unit that voltage, amperage and cir-
cuit protection requirements listed on unit data plate agree with
power supply provided.
Step 4 — Provide Unit Support
ROOF CURB MOUNT
Accessory roof curb details and dimensions are shown in Fig. 7.
Assemble and install accessory roof curb in accordance with in-
structions shipped with the curb.
Curb should be level. This is necessary for unit drain to function
properly. Unit leveling tolerances are shown in Fig. 8. Refer to
Accessory Roof Curb Installation Instructions for additional infor-
mation as required.
Fig. 8 — Unit Leveling Tolerances
Install insulation, cant strips, roofing felt, and counter flashing as
shown. Ductwork must be attached to curb and not to the unit. The
accessory thru-the-base power package must be installed before
the unit is set on the roof curb.
If electric and control wiring is to be routed through the basepan,
attach the accessory thru-the-base service connections to the base-
pan in accordance with the accessory installation instructions.
Table 2 — Operating Weights
50KC UNITS LB (KG)
04 05 06
Base Unit 445 (201) 499 (226) 552 (250)
Economizer
Vertical
Horizontal
50 (23)
80 (36)
50 (23)
80 (36)
50 (23)
80 (36)
Humidi-MiZer® System 50 (23) 50 (23) 50 (23)
Cu Fins 25 (11) 43 (20) 56 (25)
Powered Outlet 35 (16) 35 (16) 35 (16)
Curb
14-in./356 mm
24-in./610 mm
115 (52)
197 (89)
115 (52)
197 (89)
115 (52)
197 (89)
A
B
C
MAXIMUM ALLOWABLE
DIFFERENCE in. (mm)
A-B B-C A-C
0.5 (13) 1.0 (25) 1.0 (25)

11
NOTE: The gasketing of the unit to the roof curb is critical for a
watertight seal. Install gasket supplied with the roof curb as shown
in Fig. 7. Improperly applied gasket can also result in air leaks and
poor unit performance.
SLAB MOUNT (HORIZONTAL UNITS ONLY)
Provide a level concrete slab that extends a minimum of 6-in.
(150 mm) beyond unit cabinet. Install a gravel apron in front of
condenser coil air inlet to prevent grass and foliage from obstruct-
ing airflow.
NOTE: Horizontal units may be installed on a roof curb if
required.
ALTERNATE UNIT SUPPORT (IN LIEU OF CURB OR
SLAB MOUNT)
A non-combustible sleeper rail can be used in the unit curb sup-
port area. If sleeper rails cannot be used, support the long sides of
the unit with a minimum of 3 equally spaced 4-in. x 4-in. (102 mm
x 102 mm) pads on each side.
Step 5 — Field Fabricate Ductwork
Cabinet return-air static pressure (a negative condition) shall not
exceed 0.35 in. wg (87 Pa) with economizer or 0.4-in. wg (112 Pa)
without economizer.
For vertical ducted applications, secure all ducts to roof curb and
building structure. Do not connect ductwork to unit.
Fabricate supply ductwork so that the cross sectional dimensions
are equal to or greater than the unit supply duct opening dimen-
sions for the first 18 in. (458 mm) of duct length from the unit
basepan.
Insulate and weatherproof all external ductwork, joints, and roof
openings with counter flashing and mastic in accordance with ap-
plicable codes.
Ducts passing through unconditioned spaces must be insulated
and covered with a vapor barrier.
If a plenum return is used on a vertical unit, the return should be
ducted through the roof deck to comply with applicable fire codes.
FOR UNITS WITH ACCESSORY ELECTRIC HEATERS
All installations require a minimum clearance to combustible sur-
faces of 1 in. (25 mm) from duct for the first 12-in. (305 mm)
away from unit.
Outlet grilles must not lie directly below unit discharge.
NOTE: A 90 degree elbow must be provided in the ductwork to
comply with UL (Underwriters Laboratories) code for use with
electric heat.
Step 6 — Rig and Place Unit
Keep unit upright and do not drop. Spreader bars are required.
Rollers may be used to move unit across a roof. Level by using
unit frame as a reference. See Table 2 and Fig. 9 for additional in-
formation.
Lifting holes are provided in base rails as shown in Fig. 9. Refer to
rigging instructions on unit.
Before setting the unit onto the curb, recheck gasketing on curb.
Rigging materials under unit (cardboard or wood to prevent base
pan damage) must be removed PRIOR to placing the unit on the
roof curb.
When using the standard side drain connection, ensure the red
plug in the alternate bottom connection is tight. Do this before set-
ting the unit in place. The red drain pan plug can be tightened with
a 1/2-in. square socket drive extension. For further details see “Step
10 — Install External Condensate Trap and Line” on page 14.
POSITIONING ON CURB
Position unit on roof curb so that the following clearances are
maintained: 1/4-in. (6.4 mm) clearance between the roof curb and
the base rail inside the front and rear, 0.0-in. clearance between the
roof curb and the base rail inside on the duct end of the unit. This
will result in the distance between the roof curb and the base rail
inside on the condenser end of the unit being approximately 1/4-in.
(6.4 mm).
Although unit is weatherproof, guard against water from higher
level runoff and overhangs.
After unit is in position, remove rigging skids and shipping
materials.
CAUTION
PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in damage to roofing
materials.
Membrane roofs can be cut by sharp sheet metal edges. Be
careful when placing any sheet metal parts on such roof.
WARNING
PERSONAL INJURY HAZARD
Failure to follow this warning could cause personal injury.
For vertical supply and return units, tools or parts could drop
into ductwork and cause an injury. Install a 90 degree turn in
the return ductwork between the unit and the conditioned
space. If a 90 degree elbow cannot be installed, then a grille of
sufficient strength and density should be installed to prevent
objects from falling into the conditioned space. Due to electric
heater, supply duct will require 90 degree elbow.
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage.
All panels must be in place when rigging. Unit is not designed
for handling by fork truck when packaging is removed.
If using top crate as spreader bar, once unit is set, carefully
lower wooden crate off building roof top to ground. Ensure
that no people or obstructions are below prior to lowering the
crate.

12
Fig. 9 — Rigging Label
Step 7 — Convert to Horizontal and Connect
Ductwork (when required)
Unit is shipped in the vertical duct configuration. Unit without
factory-installed economizer or return-air smoke detector option
may be field-converted to horizontal ducted configuration. To
convert to horizontal configuration, remove screws from side duct
opening covers (see Fig. 10) and remove covers. Use the screws to
install the covers on vertical duct openings with the insulation-side
down. The panels must be inserted into the notches on the basepan
to properly seal. The notches are covered by the tape used to
secure the insulation to the basepan and are not easily seen. See
Fig. 11 for position of the notches in the basepan. Seals around
duct openings must be tight. Secure with screws as shown in
Fig. 12. Cover seams with foil duct tape.
Field-supplied flanges should be attached to horizontal duct open-
ings and all ductwork should be secured to the flanges. Insulate
and weatherproof all external ductwork, joints, and roof or build-
ing openings with counter flashing and mastic in accordance with
applicable codes.
Do not cover or obscure visibility to the unit’s informative data
plate when insulating horizontal ductwork.
Fig. 10 — Horizontal Conversion Panels
REMOVABLE HORIZONTAL
SUPPLY DUCT OPENING COVER
REMOVABLE HORIZONTAL
RETURN DUCT OPENING COVER

13
Fig. 11 — Location of Notches
Fig. 12 — Horizontal Duct Panels In Place
Step 8 — Install Outside Air Hood
ECONOMIZER HOOD PACKAGE REMOVAL AND
SETUP - FACTORY OPTION
1. The hood is shipped in knock-down form and must be field-
assembled. The indoor coil access panel is used as the hood
top while the hood sides, divider and filter are packaged
together, attached to a metal support tray using plastic stretch
wrap, and shipped in the return-air compartment behind the
indoor coil access panel. The hood assembly’s metal tray is
attached to the basepan and also attached to the damper using
two plastic tie-wraps.
2. To gain access to the hood, remove the filter access panel.
(See Fig. 13.)
Fig. 13 — Typical Access Panel Locations
3. Locate the 2 screws holding the metal tray to the basepan and
remove. Locate and cut the 2 plastic tie-wraps securing the
assembly to the damper. (See Fig. 14.) Be careful to not dam-
age any wiring or cut tie-wraps securing any wiring.
Fig. 14 — Economizer Hood Parts Location
4. Carefully lift the hood assembly (with metal tray) through the
filter access opening and assemble per the steps outlined in
Economizer Hood, below.
ECONOMIZER HOOD ASSEMBLY
NOTE: If the power exhaust accessory is to be installed on the
unit, the hood shipped with the unit will not be used and must be
discarded. Save the aluminum filter for use in the power exhaust
hood assembly.
1. The indoor coil access panel will be used as the top of the
hood. Remove the screws along the sides and bottom of the
indoor coil access panel. See Fig. 15.
BASEPAN
NOTCHES NOTCHES
SCREWS
DUCT COVERS
SHEET METAL
FACE UP
BASEPAN
FILTER ACCESS PANEL
OUTDOOR-AIR OPENING AND
INDOOR COIL ACCESS PANEL
COMPRESSOR
ACCESS PANEL
HOOD PARTS
PLASTIC TIE WRAP
QTY (2)
SCREWS FOR MET
QTY (2)

14
Fig. 15 — Indoor Coil Access Panel Relocation
2. Swing out indoor coil access panel and insert the hood sides
under the panel (hood top). Use the screws provided to attach
the hood sides to the hood top. Use screws provided to attach
the hood sides to the unit. See Fig. 16.
Fig. 16 — Economizer Hood Construction
3. Remove the shipping tape holding the economizer barometric
relief damper in place (economizer only).
4. Insert the hood divider between the hood sides. See Fig. 16
and Fig. 17. Secure hood divider with 2 screws on each hood
side. The hood divider is also used as the bottom filter rack
for the aluminum filter.
5. Open the filter clips which are located underneath the hood
top. Insert the aluminum filter into the bottom filter rack
(hood divider). Push the filter into position past the open filter
clips. Close the filter clips to lock the filter into place. See
Fig. 17.
6. Caulk the ends of the joint between the unit top panel and the
hood top.
7. Replace the filter access panel.
Fig. 17 — Economizer Filter Installation
Step 9 — Units with Hinged Panels Only
Relocate latch shipped inside the compressor compartment behind
the hinged compressor door to location shown in Fig. 18 after unit
installation.
If the unit does not have hinged panels, skip this step and continue
at Step 10.
Fig. 18 — Compressor Door Latch Location
Step 10 — Install External Condensate Trap
and Line
The unit has one 3/4-in. condensate drain connection on the end of
the condensate pan and an alternate connection on the bottom. See
Fig. 19. Unit airflow configuration does not determine which
drain connection to use. Either drain connection can be used with
vertical or horizontal applications.
Fig. 19 — Condensate Drain Pan (Side View)
To use the alternate bottom drain connection, remove the red drain
plug from the bottom connection (use a 1/2-in. square socket drive
extension) and install it in the side drain connection.
TOP
PANEL
INDOOR
COIL
ACCESS
PANEL
INDOOR
COIL
ACCESS
PANEL
CAULK
HERE
TOP
PANEL
B
TOP
PANEL
INDOOR COIL
ACCESS PANEL
19 1/16”
SCREW
HOOD DIVIDER
LEFT
HOOD
SIDE
33 3/8”
(848mm)
(483mm)
DIVIDER
BAROMETRIC
RELIEF
CLEANABLE
ALUMINUM
FILTER FILTER
HOOD
FILTER
CLIP
OUTSIDE
AIR
COMPRESSOR
DOOR OUTDOOR COIL
LATCH
DRAIN
(FACTORY-INSTALLED)
PLUG
CONDENSATE PAN (SIDE VIEW)
STANDARD
SIDE DRAIN
ALTERNATE
BOTTOM DRAIN

15
The piping for the condensate drain and external trap can be com-
pleted after the unit is in place. See Fig. 20.
Fig. 20 — Condensate Drain Piping Details
All units must have an external trap for condensate drainage. In-
stall a trap at least 4-in. (102 mm) deep and protect against
freeze-up. If drain line is installed downstream from the external
trap, pitch the line away from the unit at 1-in. per 10 ft (25 mm in
3 m) of run. Do not use a pipe size smaller than the unit connec-
tion (3/4-in.).
Step 11 — Make Electrical Connections
NOTE: Field-supplied wiring shall conform with the limitations
of minimum 63°F (33°C) rise.
FIELD POWER SUPPLY
If equipped with optional Powered Convenience Outlet: The pow-
er source leads to the convenience outlet’s transformer primary are
not factory-connected. Installer must connect these leads accord-
ing to required operation of the convenience outlet. If an always-
energized convenience outlet operation is desired, connect the
source leads to the line side of the unit-mounted disconnect.
(Check with local codes to ensure this method is acceptable in
your area.) If a de-energize via unit disconnect switch operation of
the convenience outlet is desired, connect the source leads to the
load side of the unit disconnect. On a unit without a unit-mounted
disconnect, connect the source leads to compressor contactor C
and indoor fan terminal block (IFTB) pressure lugs with unit field
power leads.
Refer to Fig. 27 for power transformer connections and the dis-
cussion on connecting the convenience outlet on page 16. Field
power wires are connected to the unit at line-side pressure lugs
on compressor contactor C and indoor fan contactor IFC (see
wiring diagram label for control box component arrangement) or
at factory-installed option non-fused disconnect switch. Max
wire size is #2 AWG (copper only, see Fig. 22). See Fig. 21 and
unit label diagram for field power wiring connections.
NOTE: TEST LEADS — Unit may be equipped with short leads
(pigtails) on the field line connection points on contactor C or op-
tional disconnect switch. These leads are for factory run-test pur-
poses only; remove and discard before connecting field power
wires to unit connection points. Make field power connections di-
rectly to line connection pressure lugs only.
Fig. 21 — Power Wiring Connections
Fig. 22 — Disconnect Switch and Unit
UNITS WITH FACTORY-INSTALLED NON-FUSED DIS-
CONNECT
The factory-installed option non-fused disconnect (NFD) switch is
located in a weatherproof enclosure located under the main con-
trol box. The manual switch handle and shaft are shipped in the
disconnect enclosure. Assemble the shaft and handle to the switch
at this point. Discard the factory test leads (see Fig. 21).
Connect field power supply conductors to LINE side terminals
when the switch enclosure cover is removed to attach the handle.
WARNING
ELECTRIC SHOCK HAZARD
Failure to follow this warning could result in personal injury or
death.
Unit cabinet must have an uninterrupted, unbroken electrical
ground to minimize the possibility of personal injury if an
electrical fault should occur. This ground may consist of elec-
trical wire connected to unit ground lug in control compart-
ment, or conduit approved for electrical ground when installed
in accordance with NEC; ANSI/NFPA 70, latest edition (in
Canada, Canadian Electrical Code CSA [Canadian Standards
Association] C22.1), and local electrical codes.
NOTE: Trap should be deep enough to offset maximum unit static
difference. A 4-in. (102 mm) trap is recommended.
MINIMUM PITCH
1˝ (25 mm) PER
10´ (3m) OF LINE
BASE RAIL
OPEN
VENT
TO ROOF
DRAIN
DRAIN PLUG
ROOF
CURB
SEE NOTE
3˝ (76 mm)
MIN
WARNING
FIRE HAZARD
Failure to follow this warning could result in personal injury,
death, or property damage.
Do not connect aluminum wire between disconnect switch and
unit. Use only copper wire.
Disconnect
per
NEC
Disconnect
per
NEC
208/230-1-60
11 1311 1313
L1 L2 L3
TB
CCIFC or
(1-ph
IFM)
208/230-3-60
460-3-60
575-3-60
Units Without Non-Fused Disconnect Option
Units With Non-Fused Disconnect Option
2
4
6
1
3
5
L1
L2
L3
Optional
Disconnect
Switch
Disconnect factory test leads; discard.
Factory
Wiring
COPPER
WIRE ONLY
ELECTRIC
DISCONNECT
SWITCH
ALUMINUM
WIRE

16
Fig. 23 — Location of Non-Fused Disconnect
Enclosure
To field install the NFD shaft and handle:
1. Remove the unit front panel (see Fig. 2 and 3).
2. Remove (3) hex screws on the NFD enclosure — (2) on the
face of the cover and (1) on the left side cover.
3. Remove the front cover of the NFD enclosure.
4. Make sure the NFD shipped from the factory is at OFF posi-
tion (the arrow on the black handle knob is at OFF).
5. Insert the shaft with the cross pin on the top of the shaft in the
horizontal position.
6. Measure from the tip of the shaft to the top surface of the
black pointer; the measurement should be 3.75 to 3.88 in. (95
to 99 mm).
7. Tighten the locking screw to secure the shaft to the NFD.
8. Turn the handle to the OFF position with red arrow pointing
at OFF.
9. Install the handle on to the painted cover horizontally with the
red arrow pointing to the left.
10. Secure the handle to the painted cover with (2) screws and
lock washers supplied.
11. Engaging the shaft into the handle socket, re-install (3) hex
screws on the NFD enclosure.
12. Re-install the unit front panel.
Fig. 24 — Handle and Shaft Assembly for NFD
UNITS WITHOUT FACTORY-INSTALLED NON-FUSED
DISCONNECT
When installing units, provide a disconnect switch per NEC (Na-
tional Electrical Code) of adequate size. Disconnect sizing data is
provided on the unit informative plate. Locate disconnect sizing
data on unit cabinet or within sight of the unit per national or local
codes. Do not cover unit informative plate if mounting the discon-
nect on the unit cabinet.
ALL UNITS
All field wiring must comply with NEC and all local codes. Size
wire based on MCA (Minimum Circuit Amps) on the unit infor-
mative plate. See Fig. 21 and the unit label diagram for power wir-
ing connections to the unit power terminal blocks and equipment
ground. Maximum wire size is #2 ga AWG (copper only) per pole
on contactors.
Provide a ground-fault and short-circuit over-current protection
device (fuse or breaker) per NEC Article 440 (or local codes). Re-
fer to unit informative data plate for MOCP (Maximum Over-cur-
rent Protection) device size.
All field wiring must comply with NEC and local requirements.
All units except 208/230-v units are factory wired for the voltage
shown on the nameplate. If the 208/230-v unit is to be connected
to a 208-v power supply, the control transformer must be rewired
by moving the black wire with the 1/4-in. female spade connector
from the 230-v connection and moving it to the 200-v 1/4-in. male
terminal on the primary side of the transformer. Refer to unit label
diagram for additional information. Field power wires will be con-
nected line-side pressure lugs on the power terminal block or at
factory-installed option non-fused disconnect.
NOTE: Check all factory and field electrical connections for
tightness.
CONVENIENCE OUTLETS
Two types of convenience outlets are offered on 50KC models:
Non-powered and unit-powered. Both types provide a 125-volt
GFCI (ground-fault circuit-interrupter) duplex receptacle rated at
15-A behind a hinged waterproof access cover, located on the end
panel of the unit. See Fig. 25.
NOTE: Unit powered convenience outlets are not available as fac-
tory installed options for size 04-06 single phase (-3 voltage code)
models.
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury or
death.
Units with convenience outlet circuits may use multiple
disconnects. Check convenience outlet for power status before
opening unit for service. Locate its disconnect switch, if
appropriate, and open it. Lock-out and tag-out this switch, if
necessary.

17
Fig. 25 — Convenience Outlet Location
Installing Weatherproof Cover:
A weatherproof while-in-use cover for the factory-installed conve-
nience outlets is now required by UL standards. This cover cannot
be factory-mounted due to its depth; it must be installed at unit in-
stallation. For shipment, the convenience outlet is covered with a
blank cover plate.
The weatherproof cover kit is shipped in the unit’s control box.
The kit includes the hinged cover, a backing plate and gasket.
DISCONNECT ALL POWER TO UNIT AND CONVE-
NIENCE OUTLET. LOCK-OUT AND TAG-OUT ALL
POWER.
Remove the blank cover plate at the convenience outlet; discard
the blank cover.
Loosen the two screws at the GFCI duplex outlet, until approxi-
mately 1/2-in. (13 mm) under screw heads are exposed. Press the
gasket over the screw heads. Slip the backing plate over the screw
heads at the keyhole slots and align with the gasket; tighten the
two screws until snug (do not over-tighten).
Mount the weatherproof cover to the backing plate as shown in
Fig. 26. Remove two slot fillers in the bottom of the cover to per-
mit service tool cords to exit the cover. Check for full closing and
latching.
Fig. 26 — Weatherproof Cover Installation
Non-Powered Type:
This type requires the field installation of a general-purpose 125-v
15-A circuit powered from a source elsewhere in the building. Ob-
serve national and local codes when selecting wire size, fuse or
breaker requirements, and disconnect switch size and location.
Route 125-v power supply conductors into the bottom of the utili-
ty box containing the duplex receptacle.
Unit-Powered Type:
A unit-mounted transformer is factory-installed to stepdown the
main power supply voltage to the unit to 115-v at the duplex re-
ceptacle. This option also includes a manual switch with fuse, lo-
cated in a utility box and mounted on a bracket behind the conve-
nience outlet; access is through the unit’s control box access panel.
See Fig. 25.
The primary leads to the convenience outlet transformer are not
factory-connected. Selection of primary power source is a custom-
er option. If local codes permit, the transformer primary leads can
be connected at the line-side terminals on the unit-mounted non-
fused disconnect switch; this will provide service power to the unit
when the unit disconnect switch is open. Other connection meth-
ods will result in the convenience outlet circuit being de-energized
when the unit disconnect switch is open. See Fig. 27.
Fig. 27 — Powered Convenience Outlet Wiring
Using Unit-Mounted Convenience Outlets:
Units with unit-mounted convenience outlet circuits will often re-
quire that two disconnects be opened to de-energize all power to
the unit. Treat all units as electrically energized until the conve-
nience outlet power is also checked and de-energization is con-
firmed. Observe National Electrical Code Article 210, Branch Cir-
cuits, for use of convenience outlets.
Fuse on Power Type:
The factory fuse is a Bussman1 “Fusetron” T-15, non-renewable
screw-in (Edison base) type plug fuse.
Duty Cycle:
The unit-powered convenience outlet has a duty cycle limita-
tion. The transformer is intended to provide power on an inter-
mittent basis for service tools, lamps, etc; it is not intended to
provide 15 amps loading for continuous duty loads (such as
CONVENIENCE
OUTLET GFCI
PWD-CO FUSE
SWITCH
PWD-CO TRANSFORMER
CONTROL BOX
ACCESS PANEL
COVER - WHILE-IN-USE
WEATHERPROOF
BASEPLATE FOR
GFCI RECEPTACLE
GASKET
GFCI RECEPTACLE
NOT INCLUDED
TOP
TOP
TOP
WET LOCA
TIONS
WE T LO CATIONS
UNIT
VOLTAGE
CONNECT
AS
PRIMARY
CONNECTIONS
TRANSFORMER
TERMINALS
208, 230 240 L1: RED +YEL
L2: BLU + GRA
H1 + H3
H2 + H4
460 480
L1: RED
Splice BLU + YEL
L2: GRA
H1
H2 + H3
H4
575 600 L1: RED
L2: GRA
H1
H2
1. Bussmann and Fusetron are trademarks of Cooper Technologics
Company.

18
electric heaters for overnight use). Observe a 50% limit on cir-
cuit loading above 8 amps.
Fig. 28 — Convenience Outlet Utilization Notice Label
Convenience Outlet Usage Rating:
Continuous usage: 8 amps maximum
Test the GFCI receptacle by pressing the TEST button on the face
of the receptacle to trip and open the receptacle. Check for proper
grounding wires and power line phasing if the GFCI receptacle
does not trip as required. Press the RESET button to clear the
tripped condition.
FACTORY OPTION THRU-BASE CONNECTIONS
This service connection kit consists of a 1/2-in. electrical bulkhead
connector and a 3/4-in. electrical bulkhead connector, connected to
an “L” bracket covering the embossed (raised) section of the unit
basepan in the condenser section (see Fig. 29 for shipping
position).
The 3/4-in. bulkhead connector enables the low-voltage control
wires to pass through the basepan. The 1/2-in. bulkhead connector
allows the high-voltage power wires to pass through the basepan.
See Fig. 30 and 31.
Fig. 29 — Thru-the-Base Fitting Assembly (Shown in
Shipping Position)
Fig. 30 — Thru-Base Connection Fittings (Units Built
Prior to 4/15/2019)
Fig. 31 — Thru-Base Connection Fittings (Units Built
On and After 4/15/2019)
1. Remove the “L” bracket assembly from the unit.
2. Remove connector plate assembly from the “L” bracket and
discard the “L” bracket, but retain the washer head screws
and the gasket (located between the “L” bracket and the con-
nector plate assembly).
NOTE: Take care not to damage the gasket, as it is reused in the
following step.
3. Place the gasket over the embossed area in the basepan, align-
ing the holes in the gasket to the holes in the basepan. See
Fig. 29.
4. Install the connector plate assembly to the basepan using 8 of
the washer head screws.
NOTE: If electrical connections are not going to occur at this time,
tape or otherwise cover the fittings so that moisture does not get
into the building or conduit in the interim.
Check tightness of connector lock nuts before connecting electri-
cal conduits.
Field-supplied and field-installed liquid-tight conduit connectors
and conduit may be attached to the connectors on the basepan.
Pull correctly rated high voltage and low voltage through
appropriate conduits. Connect the power conduit to the internal
disconnect (if unit is so equipped) or to the external disconnect
(through unit side panel). Remove one of the two knockouts
located on the bottom left side of the unit control box. Use this
hole for the control conduit.
LOW VOLTAGE
CONDUIT
CONNECTOR
HIGH VOLTAGE
CONDUIT
CONNECTOR
LOW VOLTAGE
CONDUIT
CONNECTOR
HIGH VOLTAGE
CONDUIT
CONNECTOR
AUXILIARY
POWER SUPPLY
(OPTIONAL)

19
UNITS WITHOUT THRU-BASE CONNECTIONS
1. Install power wiring conduit through side panel openings.
Install conduit between disconnect and control box.
2. Install power lines to terminal connections as shown in
Fig. 21.
Voltage to compressor terminals during operation must be within
voltage range indicated on unit nameplate. On 3-phase units, volt-
ages between phases must be balanced within 2% and the current
within 10%. Use the formula shown below to determine the per-
cent of voltage imbalance. Operation on improper line voltage or
excessive phase imbalance constitutes abuse and may cause dam-
age to electrical components. Such operation would invalidate any
applicable Carrier warranty.
Example: Supply voltage is 230-3-60
Determine maximum deviation from average voltage.
(AB) 227-224 = 3 v
(BC) 231-227 = 4 v
(AC) 227-226 = 1 v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
This amount of phase imbalance is satisfactory as it is below the maxi-
mum allowable 2%.
FIELD CONTROL WIRING
The 50KC unit requires an external temperature control device.
This device can be a thermostat (field-supplied) or a PremierLink
controller (available as factory-installed option or as field-installed
accessory, for use on a Carrier Comfort Network® or as a stand-
alone control) or the RTU Open Controller for Building Manage-
ment Systems using non-CCN protocols (RTU Open is available
as a factory-installed option only).
THERMOSTAT
Select a Carrier-approved accessory thermostat. When electric
heat is installed in the 50KC unit, the thermostat must be capable
of energizing the G terminal (to energize the Indoor Fan Contac-
tor) whenever there is a space call for heat (energizing the W1 ter-
minal). The accessory thermostats listed on the unit price pages
can provide this signal but they are not configured to enable this
signal as shipped.
Install the accessory thermostat according to installation instruc-
tions included with the accessory.
Locate the thermostat accessory on a solid wall in the conditioned
space to sense average temperature in accordance with the ther-
mostat installation instructions.
If the thermostat contains a logic circuit requiring 24-v power, use
a thermostat cable or equivalent single leads of different colors
with minimum of seven leads. If the thermostat does not require a
24-v source (no “C” connection required), use a thermostat cable
or equivalent with minimum of six leads. Check the thermostat in-
stallation instructions for additional features which might require
additional conductors in the cable.
For wire runs up to 50 ft (15 m), use no. 18 AWG (American
Wire Gage) insulated wire [35°C (95°F) minimum]. For 50 to 75
ft (15 to 23 m), use no. 16 AWG insulated wire [35°C (95°F)
minimum]. For over 75 ft (23 m), use no. 14 AWG insulated
wire [35°C (95°F) minimum]. All wire sizes larger than no. 18
AWG cannot be directly connected to the thermostat and will re-
quire a junction box and splice at the thermostat.
Fig. 32 — Low-Voltage Connections
UNIT WITHOUT THRU-BASE CONNECTION KIT
Pass the thermostat control wires through the hole provided in the
corner post; then feed the wires through the raceway built into the
corner post to the control box. Pull the wires over to the terminal
strip on the upper-left corner of the Controls Connection Board.
See Fig. 33.
NOTE: If thru-the-bottom connections accessory is used, refer to
the accessory installation instructions for information on routing
power and control wiring.
HEAT ANTICIPATOR SETTINGS
Set heat anticipator settings at 0.14 amp for the first stage and 0.14
amp for second-stage heating, when available.
Fig. 33 — Field Control Wiring Raceway
% Voltage
Imbalance = 100 x max voltage deviation from average voltage
average voltage
AB = 224 v
BC = 231 v
AC = 226 v
Average Voltage = (224 + 231 + 226) =681 = 227
3 3
% Voltage Imbalance = 100x 4= 1.78%
227
IMPORTANT: If the supply voltage phase imbalance is more than 2%,
contact your local electric utility company immediately.
ABC
MOTOR
X
C
G
W2
R
C
W2
G
W1
O/B/Y2 Y2
W1
R
Y1 Y1
Typical
Thermostat
Connections
T
H
E
R
M
O
S
T
A
T
(Note 1) (Note 2)
(Note 3)
1. Typical multi-function marking. Follow manufacturer’s configuration
instructions to select Y2.
2. Y2 to Y2 connection required on single-stage cooling units when
integrated economizer function is desired
3. W2 connection not required on units with single-stage heating.
Field Wiring
Central
Terminal
Board
Notes:
RACEWAY
HOLE IN END PANEL (HIDDEN)

20
Electric Heaters
The 50KC units may be equipped with field-installed accessory
electric heaters. The heaters are modular in design, with heater
frames holding open coil resistance wires strung through ceramic
insulators, line-break limit switches and a control contactor. One
or two heater modules may be used in a unit.
Heater modules are installed in the compartment below the indoor
(supply) fan outlet. Access is through the indoor access panel.
Heater modules slide into the compartment on tracks along the
bottom of the heater opening. See Fig. 34-36.
Not all available heater modules may be used in every unit. Use
only those heater modules that are UL listed for use in a specific
size unit. Refer to the label on the unit cabinet for the list of ap-
proved heaters.
Fig. 34 — Typical Access Panel Location (3-5 Ton)
Fig. 35 — Typical Component Location
Fig. 36 — Typical Module Installation
SINGLE POINT BOXES AND SUPPLEMENTARY FUSES
When the unit MOCP device value exceeds 60-A, unit-mounted
supplementary fuses are required for each heater circuit. These
fuses are included in accessory single point boxes, with power dis-
tribution and fuse blocks. The single point box will be installed di-
rectly under the unit control box, just to the left of the partition
separating the indoor section (with electric heaters) from the out-
door section. The single point box has a hinged access cover. See
Fig. 37. The single point box also includes a set of power taps and
pigtails to complete the wiring between the single point box and
the unit’s main control box terminals. Refer to the accessory heater
and single point box installation instructions for details on tap con-
nections.
All fuses on 50KC units are 60-A. (Note that all heaters are quali-
fied for use with a 60-A fuse, regardless of actual heater ampacity,
so only 60-A fuses are necessary.)
SINGLE POINT BOXES WITHOUT FUSES
Unit heater applications not requiring supplemental fuses require a
special single point box without any fuses. The accessory single
point boxes contain a set of power taps and pigtails to complete
the wiring between the single point box and the unit’s main control
box terminals. Refer to accessory heater and single point box in-
stallation instructions for details on tap connections.
Fig. 37 — Typical Single Point Installation
DISCONNECT MOUNTING
LOCATION
UNIT BLOCK-OFF
PANEL
OUTDOOR
ACCESS PANEL
INDOOR
ACCESS
PANEL
DISCONNECT
MOUNTING
LOCATION
EMT OR RIGID CONDUIT
(FIELD-SUPPLIED)
SINGLE
POINT BOX
CENTER
POST
HEATER
COVERS
HEATER
MOUNTING
BRACKET
HEATER
MODULE
(LOCATION 2)
HEATER
MODULE
(LOCATION 1)
SINGLE POINT
BOX
MOUNTING
SCREW
BRACKET AND
CONDUIT
DRIP BOOT
MAIN
CONTROL
BOX
CONTROL WIRE TERMINAL BLOCK
MANUAL RESET
LIMIT SWITCH
TRACK
FLANGE
ALLIEDPA
MODELNO.
ERIALNO.
CORP
.
11 13
21 23
OD
22.2
3
1
23
ISTEDAIR
NDITIONING
UIPACCESS
346N
.
P/N
2- 5610-4
REV
1113
2123
CONTROL
BOX
BUSHING
SINGLE
POINT BOX
MOUNTING
SCREWS
FOAM
BUSHING
DRIP BOOT
BRACKET
MOUNTING
SCREWS
HEATER
RELAYS
POWER
WIRES
HEATER
MOUNTING
SCREWS