50SD
Legacyt Single--Packaged Air Conditioner System
With R--22 Refrigerant
Single-- and Three--Phase Units Sizes 024--060
Installation Instructions
NOTE: Read the entire instruction manual before starting the
installation.
NOTE: Installer: Make sure the Owner’s Manual and Service
Instructions are left with the unit after installation.
TABLE OF CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . 1
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
RECEIVING AND INSTALLATION . . . . . . . . . . . . . . . . . 2--9
Check Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Identify Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Inspect Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Provide Unit Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Roof Curb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Slab Mount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Ground Mount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Provide Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Field Fabricate Ductwork . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Rig and Place Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Use of Rigging Bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Connect Condensate Drain . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Install Duct Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Configuring Units for Downflow (Vertical) Discharge . . . . . 7
Install Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . 8
High--Voltage Connections . . . . . . . . . . . . . . . . . . . . . . . . 9
Special Procedures for 208v Operation . . . . . . . . . . . . . . . 9
Control Voltage Connections . . . . . . . . . . . . . . . . . . . . . . . 9
Standard Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Transformer Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
PRE--START--UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
START--UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11--16
Check for Refrigerant Leaks . . . . . . . . . . . . . . . . . . . . . . . . 11
Start--Up Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Checking Cooling Control Operation . . . . . . . . . . . . . . . 11
Checking and Adjusting Refrigerant Charge . . . . . . . . . . 11
Indoor Airflow and Airflow Adjustments . . . . . . . . . . . . 11
Cooling Sequence of Operation . . . . . . . . . . . . . . . . . . . . 16
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16--18
Air Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Indoor Blower and Motor . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Outdoor Coil, Indoor Coil, and Condensate Drain Pan . . . . 17
Outdoor Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Electrical Controls and Wiring . . . . . . . . . . . . . . . . . . . . . . 18
Refrigerant Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Indoor Airflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Metering Devices–AccuRater® Piston . . . . . . . . . . . . . . . . 18
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
START--UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
C99001
Fig. 1 -- Unit 50SD
SAFETY CONSIDERATIONS
Installation and servicing of this equipment can be hazardous due to
mechanical and electrical components. Only trained and qualified
personnel should install, repair, or service this equipment.
Untrained personnel can perform basic maintenance functions such
as cleaning and replacing air filters. All other operations must be
performed by trained service personnel. When working on this
equipment, observe precautions in the literature, on tags, and on
labels attached to or shipped with the unit and other safety
precautions that may apply.
Follow all safety codes. Installation must be in compliance with
local and national building codes. Wear safety glasses, protective
clothing, and work gloves. Have fire extinguisher available. Read
these instructions thoroughly and follow all warnings or cautions
included in literature and attached to the unit.
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 these signal
words: DANGER, WARNING, and CAUTION. 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 suggestions which will result in enhanced installation, reliability, or operation.
1
!
recirculate to the outdoor coil. Do not locate the unit in either a
corner or under an overhead obstruction. The minimum clearance
under a partial overhang (such as a normal house overhang) is 48 in.
above the unit top. The maximum horizontal extension of a partial
overhang must not exceed 48 in.
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
IMPORTANT: Do not restrict outdoor airflow. An air restriction at
either the outdoor--air inlet or the fan discharge may be detrimental
to compressor life.
Before installing or servicing system, always turn off main
power to system. There may be more than one disconnect
switch. Turn off accessory heater power switch if applicable.
Do not place the unit where water, ice, or snow from an overhang
or roof will damage or flood the unit. Do not install the unit on
carpeting or other combustible materials. Slab--mounted units
should be at least 4 in. above the highest expected water and runoff
levels. Do not use unit if it has been under water.
50SD
INTRODUCTION
The 50SD packaged air conditioner is fully self--contained and
designed for outdoor installation (See Fig. 1). See Fig. 2 and 3 for
unit dimensions. All unit sizes have discharge openings for both
horizontal and downflow configurations, and are factory shipped
with all downflow duct openings covered. The unit may be installed
either on a rooftop, gound--level cement slab, or directly on the
gound if local codes permit. (See Fig. 4 for roof curb dimensions.)
Step 4—Field--Fabricate Ductwork
Secure all ducts to roof curb and building structure on vertical
discharge units. Do not connect ductwork to unit. For horizontal
applications, unit is provided with flanges on the horizontal
openings. All ductwork should be secured to the flanges. Insulate
and weatherproof all external ductwork, joints, and roof openings
with counter flashing and mastic in accordance with applicable
codes.
RECEIVING AND INSTALLATION
Step 1—Check Equipment
IDENTIFY UNIT
Ducts passing through an unconditioned space 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. A minimum clearance is not
required around ductwork. Cabinet return--air static shall not exceed
--.25 in. wc.
The unit model number and serial number are printed on the unit
informative plate. Check this information against shipping papers.
INSPECT SHIPMENT
Inspect for shipping damage while unit is still on shipping pallet. If
unit appears to be damaged or is torn loose from its anchorage, have
it examined by transportation inspectors before removal. Forward
claim papers directly to transportation company. Manufacturer is
not responsible for any damage incurred in transit. Check all items
against shipping list. Immediately notify the nearest Carrier Air
Conditioning office if any item is missing. To prevent loss or
damage, leave all parts in original packages until installation.
Step 5—Rig and Place Unit
Rigging and handling of this equipment can be hazardous for many
reasons due to the installation location (roofs, elevated structures,
etc.).
Only trained, qualified crane operators and ground support staff
should handle and install this equipment.
Step 2—Provide Unit Support
When working with this equipment, observe precautions in the
literature, on tags, stickers, and labels attached to the equipment, and
any other safety precautions that might apply.
For hurricane tie downs, contact distributor for details and PE
(Professional Engineering) Certificate if required.
ROOF CURB
Training for operators of the lifting equipment should include, but
not be limited to, the following:
Install accessory roof curb in accordance with instructions shipped
with curb (See Fig. 4). Install insulation, cant strips, roofing, and
flashing. Ductwork must be attached to curb.
1. Application of the lifter to the load, and adjustment of the
lifts to adapt to various sizes or kinds of loads.
2. Instruction in any special operation or precaution.
IMPORTANT: The gasketing of the unit to the roof curb is critical
for a water tight seal. Install gasketing material supplied with the
roof curb. Improperly applied gasketing also can result in air leaks
and poor unit performance.
3. Condition of the load as it relates to operation of the lifting
kit, such as balance, temperature, etc.
Follow all applicable safety codes. Wear safety shoes and work
gloves.
Curb should be level to within 1/4 in. (See Fig. 6). This is necessary
for unit drain to function properly. Refer to accessory roof curb
installation instructions for additional information as required.
INSPECTION
Prior to initial use, and at monthly intervals, all rigging brackets and
straps should be visually inspected for any damage, evidence of
wear, structural deformation, or cracks. Particular attention should
be paid to excessive wear at hoist hooking points and load support
areas. Brackets or straps showing any kind of wear in these areas
must not be used and should be discarded.
SLAB MOUNT
Place the unit on a solid, level concrete pad that is a minimum of 4
in. thick with 2 in. above grade. The slab should extend
approximately 2 in. beyond the casing on all 4 sides of the unit (See
Fig. 7). Do not secure the unit to the slab except when required by
local codes.
!
GROUND MOUNT
The unit may be installed either on a slab or placed directly on the
ground if local codes permit. Place the unit on level ground prepared
with gravel for condensate discharge.
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Step 3—Provide Clearances
Before installing or servicing system, always turn off main
power to system. There may be more than one disconnect
switch. Turn off accessory heater power switch if applicable.
Tag disconnect switch with a suitable warning label.
The required minimum service clearances are shown in Fig. 2 and
3. Adequate ventilation and outdoor air must be provided. The
outdoor fan draws air through the outdoor coil and discharges it
through the top fan grille. Be sure that the fan discharge does not
2
50SD
REQUIRED CLEARANCE FOR OPERATION AND SERVICING
REQUIRED CLEARANCE TO COMBUSTIBLE MATL.
(Refer to Maximum Operating Clearances)
INCHES [mm]
TOP OF UNIT...................................................................................14.00 [355.6]
DUCT SIDE OF UNIT.........................................................................2.00 [50.8]
SIDE OPPOSITE DUCTS ................................................................14.00 [355.6]
BOTTOM OF UNIT .............................................................................0.50 [12.7]
INCHES [mm]
EVAP. COIL ACCESS SIDE............................................................36.00 [914.0]
POWER ENTRY SIDE....................................................................42.00 [1066.8]
(EXCEPT FOR NEC REQUIREMENTS)
UNIT TOP .......................................................................................48.00 [1219.2]
SIDE OPPOSITE DUCTS ..............................................................36.00 [914.0]
DUCT PANEL .................................................................................12.00 [304.8] *
NEC. REQUIRED CLEARANCES.
*MINIMUM DISTANCES: IF UNIT IS PLACED LESS THAN 304.8 [12.00] FROM
WALL SYSTEM, THEN SYSTEM PERFORMANCE MAYBE COMPROMISE.
INCHES [mm]
BETWEEN UNITS, POWER ENTRY SIDE ....................................42.00 [1066.8]
UNIT AND UNGROUNDED SURFACES, POWER ENTRY SIDE .36.00 [914.0]
UNIT AND BLOCK OR CONCRETE WALLS AND OTHER
GROUNDED SURFACES, POWER ENTRY SIDE.........................42.00 [1066.8]
A05162
UNIT HEIGHT
IN. [MM]
“A”
UNIT WEIGHT
UNIT
ELECTRICAL
CHARACTERISTICS
50SD024
50SD030
208/230--1--60
208/230--1--60, 208/230--3--60
lb
343
366
kg
156
166
39.02 [991]
41.02 [1042]
Fig. 2 -- 50SD024--030 Unit Dimensions
3
CENTER OF GRAVITY
IN. [MM]
X
Y
Z
20.0 [508]
19.3 [490]
17.6 [447]
20.0 [508]
14.0 [356]
13.0 [330]
50SD
REQUIRED CLEARANCE TO COMBUSTIBLE MATL.
(Refer to Maximum Operating Clearances)
REQUIRED CLEARANCE FOR OPERATION AND SERVICING
INCHES [mm]
TOP OF UNIT...................................................................................14.00 [355.6]
DUCT SIDE OF UNIT.........................................................................2.00 [50.8]
SIDE OPPOSITE DUCTS ................................................................14.00 [355.6]
BOTTOM OF UNIT .............................................................................0.50 [12.7]
INCHES [mm]
EVAP. COIL ACCESS SIDE............................................................36.00 [914.0]
POWER ENTRY SIDE....................................................................42.00 [1066.8]
(EXCEPT FOR NEC REQUIREMENTS)
UNIT TOP .......................................................................................48.00 [1219.2]
SIDE OPPOSITE DUCTS ..............................................................36.00 [914.0]
DUCT PANEL .................................................................................12.00 [304.8] *
NEC. REQUIRED CLEARANCES.
*MINIMUM DISTANCES: IF UNIT IS PLACED LESS THAN 304.8 [12.00] FROM
WALL SYSTEM, THEN SYSTEM PERFORMANCE MAYBE COMPROMISE.
INCHES [mm]
BETWEEN UNITS, POWER ENTRY SIDE ....................................42.00 [1066.8]
UNIT AND UNGROUNDED SURFACES, POWER ENTRY SIDE .36.00 [914.0]
UNIT AND BLOCK OR CONCRETE WALLS AND OTHER
GROUNDED SURFACES, POWER ENTRY SIDE.........................42.00 [1066.8]
A05126
UNIT
50SD036
50SD042
50SD048
50SD060
ELECTRICAL
CHARACTERISTICS
208/230--1--60,
208/230--1--60,
208/230--1--60,
208/230--1--60,
208/230--3--60,
208/230--3--60,
208/230--3--60,
208/230--3--60,
460--3--60
460--3--60
460--3--60
460--3--60
UNIT WEIGHT
lb
433
460
480
492
kg
196
209
218
223
UNIT HEIGHT
IN. [MM]
“A”
42.98 [1092]
46.98 [1193]
46.98 [1193]
46.98 [1193]
Fig. 3 -- 50SD036--060 Unit Dimensions
4
CENTER OF GRAVITY
IN. [MM]
X
Y
Z
21.0 [533]
20.5 [520]
16.6 [422]
21.0 [533]
20.5 [520]
17.1 [434]
21.0 [533]
20.0 [508]
17.4 [442]
21.0 [533]
20.0 [508]
17.6 [447]
HVAC unit
base
HVAC unit
base
Screw
(NO TE A)
Gask eting
inner flange*
Screw
(NOTE A)
Gasketing
inner flange*
*Gasketing
outer flange
*Gasketing
outer flange
Wood nailer*
Wood nailer*
Flashing field
supplied
Roof curb*
Insulation (field
supplied)
Roofing material
field supplied
Insulation (field
supplied)
Roofing material
field supplied
Ductwork
field supplied
Cant strip
field supplied
Roof curb*
Ductwork
field supplied
Cant strip
field supplied
Roof
Roof
*Provided with roof curb
*Provided with roof curb
Roof Curb for Small Cabinet
Roof Curb for Large Cabinet
Note A: When unit mounting scre w is used,
retainer bracket must also be used.
Note A: When unit mounting scre w is used,
retainer bracket must also be used.
E
G
Supply opening
(B x C)
G
B Typ.
F
F
D
CTyp.
R/A
S/A
A
E
Insulated
deck pan
50SD
Flashing field
supplied
Gasket around
duct
D
Insulated
deck pan
Short
Support
Gasket around
outer edge
Long
Support
Return opening
(B X C)
A05308
UNIT SIZE
50SD024-- 030
50SD036-- 060
ODS CATALOG
NUMBER
CPRFCURB006A00
CPRFCURB007A00
CPRFCURB008A00
CPRFCURB009A00
A
IN. (MM)
8 (203)
14 (356)
8 (203)
14 (356)
B
IN. (MM)
11 (279)
11 (279)
16--3/16 (411)
16--3/16 (411)
C
IN. (MM)
16--1/2 (419)
16--1/2 (419)
17--3/8 (441)
17--3/8 (441)
D
IN. (MM)
28--3/4 (730)
28--3/4 (730)
40--1/4 (1022)
40--1/4 (1022)
E
IN. (MM)
30--3/8 (771)
30--3/8 (771)
41--15/16 (1065)
41--15/16 (1065)
F
IN. (MM)
44--5/16 (1126)
44--5/16 (1126)
44--7/16 (1129)
44--7/16 (1129)
G
IN. (MM)
45--15/16 (1167)
45--15/16 (1167)
46--1/16 (1169)
46--1/16 (1169)
NOTES:
1. Roof curb must be set up for unit being installed.
2. Seal strip must be applied, as required, to unit being installed.
3. Dimensions are in inches.
4. Dimension in ( ) are in millimeters.
5. Roof curb is made of 16--gauge steel.
6. Attach ductwork to curb (flanges of duct rest on curb).
7. Insulated panels: 1--in. thick fiberglass 1 lb. density.
8. When unit mounting screw is used (see Note A), a retainer bracket must be used as well. This bracket must also be used when required by code for hurricane or seismic
conditions. This bracket is available through Micrometl.
Fig. 4 -- Roof Curb Dimensions
5
1
2
y
DETAIL A
4
3
x
50SD
C00071
A05161
CORNER WEIGHTS (SMALL CABINET)
CORNER WEIGHTS (LARGE CABINET)
Unit
024
030
Unit
036
042
048
060
Total Weight
343
366
Total Weight
433
460
480
492
Corner Weight 1
69
74
Corner Weight 1
87
93
97
99
Corner Weight 2
53
57
Corner Weight 2
68
72
74
76
Corner Weight 3
83
88
Corner Weight 3
104
111
116
119
Corner Weight 4
138
147
Corner Weight 4
174
184
193
198
Rigging Weight
353
376
Rigging Weight
443
470
490
502
Fig. 5 -- 50SD Unit Corner Weights (in Pounds) and Suggested Rigging
!
WARNING
UNIT FALLING HAZARD
A
Failure to follow this warning could result in personal injury
or death.
C
MAXIMUM ALLOWABLE
DIFFERENCE (in.)
B
Never stand beneath rigged units or lift over people.
A-B
B-C
A-C
INSTALLATION
1/4
1/4
1/4
The lifting/rigging bracket is engineered and designed to be
installed only on Small Packaged Products. This bracket is to be
used to rig/lift a Small Packaged Product onto roofs or other
elevated structures.
C99065
Fig. 6 -- Unit Leveling Tolerances
!
OPTIONAL
RETURN
AIR
OPENING
OPTIONAL
SUPPLY
AIR
OPENING
WARNING
PROPERTY DAMAGE HAZARD
Failure to follow this warning could result in personal
injury/death or property damage.
Rigging brackets for one unit use only. When removing a
unit at the end of its useful life, use a new set of brackets.
USE OF RIGGING BRACKET
2"
Field Installation of Rigging Bracket
EVAP. COIL
1. If applicable, remove unit from shipping carton. Leave top
shipping skid on the unit for use as a spreader bar to prevent
the rigging straps from damaging the unit. If the skid is not
available, use a spreader bar of sufficient length to protect the
unit from damage.
COND. COIL
C99096
Fig. 7 -- Slab Mounting Detail
2. Remove 4 screws in unit corner posts.
6
3. Attach each of the 4 metal rigging brackets under the panel
rain lip (See Fig. 5). Use the screws removed in step 2 above
to secure the brackets to the unit.
1” (25mm) MIN.
WARNING
TRAP
OUTLET
2” (50mm) MIN.
PROPERTY DAMAGE HAZARD
Failure to follow this warning could result in personal
injury/death or property damage.
C99013
Fig. 8 -- Condensate Trap
Rigging bracket MUST be under the rain lip to provide
adequate lifting.
!
Step 7—Install Duct Connections
The design and installation of the duct system must be in accordance
with the standards of the NFPA for installation of non--residence
type air conditioning and ventilating systems, NFPA 90A or
residence type, NFPA 90B and/or local codes and ordinances.
WARNING
PROPERTY DAMAGE HAZARD
Select and size ductwork, supply--air registers, and return air grilles
according to ASHRAE (American Society of Heating,
Refrigeration, and Air Conditioning Engineers) recommendations.
The unit has duct flanges on the supply-- and return--air openings on
the side of the unit.
Failure to follow this warning could result in personal
injury/death or property damage.
Do not strip screws when re--securing the unit. If a screw is
stripped, replace the stripped one with a larger diameter screw
(included).
When designing and installing ductwork, consider the following:
Rigging/Lifting of Unit
1. All units should have field--supplied filters or accessory filter
rack installed in the return--air side of the unit.
Recommended sizes for filters are shown in Table 1.
1. Bend top of brackets down approximately 30 degrees from
the corner posts.
2. Avoid abrupt duct size increases and reductions. Abrupt
change in duct size adversely affects air performance.
2. Attach straps of equal length to the rigging brackets at
opposite ends of the unit. Be sure straps are rated to hold the
weight of the unit (See Fig. 5).
IMPORTANT: Use flexible connectors between ductwork and
unit to prevent transmission of vibration. Use suitable gaskets to
ensure weather--tight and airtight seal. When electric heat is
installed, use fireproof canvas (or similar heat resistant material)
connector between ductwork and unit discharge connection. If
flexible duct is used, insert a sheet metal sleeve inside duct. Heat
resistant duct connector (or sheet metal sleeve) must extend 24--in.
from electric heater element.
3. Attach a clevis of sufficient strength in the middle of the
straps. Adjust the clevis location to ensure unit is lifted level
with the ground.
4. After unit is securely in place detach rigging straps. Remove
corner posts, screws, and rigging brackets then reinstall
screws.
!
WARNING
3. Size ductwork for cooling air quantity (cfm). The minimum
air quantity for proper electric heater operation is listed in
Table 2. Heater limit switches may trip at air quantities below
those recommended.
UNIT FALLING HAZARD
Failure to follow this warning could result in personal
injury/death or property damage.
4. Seal, insulate, and weatherproof all external ductwork. Seal,
insulate and cover with a vapor barrier all ductwork passing
through conditioned spaces. Follow latest Sheet Metal and
Air Conditioning Contractors National Association
(SMACNA) and Air Conditioning Contractors Association
(ACCA) minimum installation standards for residential
heating and air conditioning systems.
When straps are taut, the clevis should be a minimum of 36
inches above the unit top cover.
After the unit is placed on the roof curb or mounting pad, remove
the top crating.
Step 6—Connect Condensate Drain
NOTE: When installing condensate drain connection be sure to
comply with local codes and restrictions.
5. Secure all ducts to building structure. Flash, weatherproof,
and vibration--isolate duct openings in wall or roof
according to good construction practices.
Model 50SD disposes of condensate water through a 3/4 in. NPT
fitting which exits through the base on the evaporator coil access
side. See Fig. 2 & 3 for location.
CONFIGURING UNITS FOR DOWNFLOW (VERTICAL)
DISCHARGE
Condensate water can be drained directly onto the roof in rooftop
installations (where permitted) or onto a gravel apron in ground
level installations. Install a field--supplied condensate trap at end of
condensate connection to ensure proper drainage. Make sure that
the outlet of the trap is at least 1 in. lower than the drain pan
condensate connection to prevent the pan from overflowing (See
Fig. 8). When using a gravel apron, make sure it slopes away from
the unit.
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Before performing service or maintenance operations on the
system, turn off main power to unit and install lockout tag.
Connect a drain tube using a minimum of 3/4 --in. PVC or 3/4 --in.
copper pipe (all field--supplied) at the outlet end of the 2--in. trap. Do
not undersize the tube. Pitch the drain tube downward at a slope of
at least 1--in. for every 10 ft of horizontal run. Be sure to check the
1. Open all electrical disconnects and install lockout tag before
starting any service work.
7
50SD
!
drain tube for leaks. Prime trap at the beginning of the cooling
season start--up.
2. Remove return duct cover located on duct panel by breaking
four (4) connecting tabs with screwdriver and a hammer (See
Fig. 9 & 10).
3. To remove supply duct cover, break front and right side
connecting tabs with a screwdriver and a hammer. Push
louver down to break rear and left side tabs (See Fig. 9 & 10).
4. If unit ductwork is to be attached to vertical opening flanges
on the unit composite base (jackstand applications only), do
so at this time. Collect ALL screws that were removed. Do
not leave screws on rooftop as permanent damage to the roof
may occur.
50SD
5. It is recommended that the unit base insulation around the
perimeter of the vertical return--air opening be secured to the
unit base with aluminum tape. Applicable local codes may
require aluminum tape to prevent exposed fiberglass.
RETURN
DUCT
OPENING
SUPPLY
DUCT
OPENING
6. Cover both horizontal duct openings with the duct covers
from the accessory duct cover kit. Ensure opening is air--and
watertight.
C99011
Fig. 9 -- Supply and Return Duct Opening
7. After completing unit conversion, perform all safety checks
and power up unit.
NOTE:The design and installation of the duct system must be in
accordance with the standards of the NFPA for installation of
nonresidence--type air conditioning and ventilating systems, NFPA
90A or residence--type, NFPA 90B; and/or local codes and
ordinances.
Adhere to the following criteria when selecting, sizing, and
installing the duct system:
1. Units are shipped for side shot installation.
2. Select and size ductwork, supply--air registers, and
return--air grilles according to American Society of Heating,
Refrigeration and Air Conditioning Engineers (ASHRAE)
recommendations.
3. Use flexible transition between rigid ductwork and unit to
prevent transmission of vibration. The transition may be
screwed or bolted to duct flanges. Use suitable gaskets to
ensure weather--tight and airtight seal.
DUCT COVERS REMOVED
C99012
Fig. 10 -- Vertical Duct Cover Removed
4. All units must have field--supplied filters or accessory filter
rack installed in the return--air side of the unit.
Recommended sizes for filters are shown in Table 1.
Step 8—Install Electrical Connections
!
5. Size all ductwork for maximum required airflow (either
heating or cooling) for unit being installed. Avoid abrupt
duct size increases or decreases or performance may be
affected.
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
6. Adequately insulate and weatherproof all ductwork located
outdoors. Insulate ducts passing through unconditioned
space, and use vapor barrier in accordance with latest issue
of Sheet Metal and Air Conditioning Contractors National
Association (SMACNA) and Air Conditioning Contractors
of America (ACCA) minimum installation standards for
heating and air conditioning systems. Secure all ducts to
building structure.
The 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
an electrical wire connected to the unit ground screw in the
control compartment, or conduit approved for electrical
ground when installed in accordance with NEC, ANSI/NFPA
American National Standards Institute/National Fire
Protection Association (latest edition) (in Canada, Canadian
Electrical Code CSA C22.1) and local electrical codes.
7. Flash, weatherproof, and vibration--isolate all openings in
building structure in accordance with local codes and good
building practices.
8
SPECIAL PROCEDURES FOR 208--V OPERATION
CAUTION
!
UNIT COMPONENT DAMAGE HAZARD
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this caution may result in damage to the unit
being installed.
Failure to follow this warning could result in personal injury
or death.
1. Make all electrical connections in accordance with NEC
ANSI/NFPA (latest edition) and local electrical codes
governing such wiring. In Canada, all electrical
connections must be in accordance with CSA standard
C22.1 Canadian Electrical Code Part 1 and applicable local
codes. Refer to unit wiring diagram.
Make sure that the power supply to the unit is switched OFF
and lockout tag installed before making any wiring changes.
CONTROL VOLTAGE CONNECTIONS
NOTE:Do not use any type of power--stealing thermostat. Unit
control problems may result.
2. Use only copper conductor for connections between
field--supplied electrical disconnect switch and unit. DO
NOT USE ALUMINUM WIRE.
Use no. 18 American Wire Gage (AWG) color--coded, insulated
(35° C minimum) wires to make the control voltage connections
between the thermostat and the unit. If the thermostat is located more
than 100 ft from the unit (as measured along the control voltage
wires), use no. 16 AWG color--coded, insulated (35° C minimum)
wires.
3. Be sure that high--voltage power to unit is within operating
voltage range indicated on unit rating plate. On 3--phase
units, ensure phases are balanced within 2 percent. Consult
local power company for correction of improper voltage
and/or phase imbalance.
STANDARD CONNECTION
4. Do not damage internal components when drilling through
any panel to mount electrical hardware, conduit, etc.
Remove knockout hole located in the electric heat panel adjacent to
the control access panel. See Fig. 2 & 3. Remove the rubber
grommet from the installer’s packet (included with unit) and install
grommet in the knockout opening. Provide a drip loop before
running wire through panel.
HIGH--VOLTAGE CONNECTIONS
The unit must have a separate electrical service with a
field--supplied, waterproof disconnect switch mounted at, or within
sight from the unit. Refer to the unit rating plate, NEC and local
codes for maximum fuse/circuit breaker size and minimum circuit
amps (ampacity) for wire sizing.
Run the low--voltage leads from the thermostat, through the inlet
hole, and into unit low--voltage splice box.
Locate five 18--gage wires leaving control box. These low--voltage
connection leads can be identified by the colors red, green, yellow,
brown (See Fig. 11). Ensure the leads are long enough to be routed
into the low--voltage splice box (located below right side of control
box). Stripped yellow wire is located in connection box. Route leads
through hole in bottom of control box and make low--voltage
connections (See Fig. 11). Secure all cut wires, so that they do not
interfere with operation of unit.
The field--supplied disconnect may be mounted on the unit over the
high--voltage inlet hole when the standard power and low--voltage
entry points are used. See Fig. 2 and 3 for acceptable location.
See unit wiring label and Fig. 11 for reference when making high
voltage connections. Proceed as follows to complete the
high--voltage connections to the unit.
Single phase units:
TRANSFORMER PROTECTION
1. Run the high--voltage (L1, L2) and ground lead into the
control box.
The transformer is of the energy--limiting type. It is set to withstand
a 30--second overload or shorted secondary condition.
2. Connect ground lead to chassis ground connection.
3. Locate the black and yellow wires connected to the line side
of the contactor.
HIGH VOLTAGE
POWER LEADS
(SEE UNIT WIRING
LABEL)
4. Connect field L1 to black wire on connection 11 of the
compressor contactor.
POWER
SUPPLY
5. Connect field wire L2 to yellow wire on connection 23 of the
compressor contactor.
Three--phase units:
GND
FIELD-SUPPLIED
FUSED DISCONNECT
CONTROL BOX
1. Run the high--voltage (L1, L2, L3) and ground lead into the
control box.
YEL(Y)
2. Connect ground lead to chassis ground connection.
GRN(G)
LOW-VOLTAGE
POWER LEADS
(SEE UNIT
WIRING LABEL)
3. Locate the black and yellow wires connected to the line side
of the contactor.
4. Connect field L1 to black wire on connection 11 of the
compressor contactor.
RED(R)
BRN(C)
Y
G
THERMOSTAT
(TYPICAL)
R
C
SPLICE BOX
5. Connect field wire L2 to yellow wire on connection 13 of the
compressor contactor.
LEGEND
Field Control-Voltage Wiring
Field High-Voltage Wiring
NOTE: Use blue wire for 3-phase units only.
6. Connect field wire L3 to blue wire from compressor.
C99010
Fig. 11 -- High-- and Control--Voltage Connections
9
50SD
!
50SD
Table 1—Physical Data--Unit 50SD
UNIT SIZE
024
030
036
042
048
060
NOMINAL CAPACITY (ton)
2
2--1/2
3
3--1/2
4
5
OPERATING WEIGHT (lb.)
289
312
371
398
418
430
COMPRESSOR
Scroll
REFRIGERANT (R--22) Quantity (lb.)
7.8
8.2
10.7
10.8
12.1
11.8
REFRIGERANT METERING DEVICE
AccuRater®
ORIFICE OD (in.)
0.065
0.070
0.080
0.088
0.088
0.101
OUTDOOR COIL
Rows…Fins/in.
2…21
2…21
2…21
2…21
2…21
2…21
Face Area (sq. ft.)
11.9
13.6
15.5
19.4
19.4
19.4
OUTDOOR FAN
Nominal Cfm
2700
2700
2800
2800
3300
3300
Diameter
22
22
22
22
22
22
Motor HP (RPM)
1/8 (825)
1/8 (825)
1/8 (825)
1/8 (825)
1/4 (1100)
1/4 (1100)
INDOOR COIL
Rows…Fins/in.
3…17
3…17
3…17
3…17
3…17
4…17
Face Area (sq. ft.)
3.7
3.7
4.7
4.7
5.6
5.6
INDOOR BLOWER
Nominal Airflow (Cfm)
800
1000
1200
1400
1600
1750
Size (in.)
10x10
10x10
11x10
11x10
11x10
11x10
Motor HP (RPM)
1/3 (1050)
1/3 (1050)
1/2 (1000)
1/2 (1075)
1/2 (1075)
1.0 (1040)
RETURN--AIR FILTERS (IN.)*
20x24x1
20x24x1
24x36x1
24x36x1
24x36x1
24x36x1
Throwaway
*Required filter sizes shown are based on the larger of the ARI (Air Conditioning and Refrigeration Institute) rated cooling airflow or the heating airflow velocity
of 300 ft/minute for throwaway type. For permanent filters, follow filter manufacturer’s recommendations for filter size based on allowable face velocity. Air filter
pressure drop for non ---standard filters must not exceed 0.08 in. wc.
Table 2—Minimum Airflow for Safe Electric Heater Operation (Cfm)
SIZE
Cfm
024
800
030
1000
036
1200
042
1400
PRE--START--UP
!
048
1600
060
1750
b. Inspect for oil at all refrigerant tubing connections and on
unit base. Detecting oil generally indicates a refrigerant
leak. Leak test all refrigerant tubing connections using
electronic leak detector, or liquid--soap solution. If a
refrigerant leak is detected, see following Check for
Refrigerant Leaks section.
WARNING
FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death and/or property damage.
1. Follow recognized safety practices and wear protective
goggles when checking or servicing refrigerant system.
2. Relieve and recover all refrigerant from system before
touching or disturbing anything inside terminal box if
refrigerant leak is suspected around compressor terminals.
3. Never attempt to repair soldered connection while
refrigerant system is under pressure.
4. Do not use torch to remove any component. System
contains oil and refrigerant under pressure.
5. To remove a component, wear protective goggles and
proceed as follows:
a. Shut off electrical power to unit and install lockout
tag.
b. Relieve and reclaim all refrigerant from system
using both high-- and low--pressure ports.
c. Cut component connecting tubing with tubing
cutter and remove component from unit.
d. Carefully unsweat remaining tubing stubs when
necessary. Oil can ignite when exposed to torch
flame.
c. Inspect all field-- and factory--wiring connections. Be
sure that connections are completed and tight.
d. Ensure wires do not touch refrigerant tubing or sharp
sheet metal edges.
e. Inspect coil fins. If damaged during shipping and
handling, carefully straighten fins with a fin comb.
4. Verify the following conditions:
a. Make sure that outdoor fan blade is correctly positioned
in fan orifice (See Fig. 12).
b. Make sure that condensate drain pan and trap are filled
with water to ensure proper drainage.
c. Make sure that all tools and miscellaneous loose parts
have been removed.
FAN GRILLE
MOTOR
Proceed as follows to inspect and prepare the unit for initial start--up:
1/8" MAX BETWEEN
MOTOR AND FAN HUB
1. Remove all access panels.
1/2ý
MOTOR SHAFT
C99009
2. Read and follow instructions on all DANGER, WARNING,
CAUTION, and INFORMATION labels attached to, or
shipped with unit.
Fig. 12 -- Fan Blade Clearance
3. Make the following inspections:
a. Inspect for shipping and handling damages, such as
broken lines, loose parts, disconnected wires, etc.
10
CHECK FOR REFRIGERANT LEAKS
Proceed as follows to locate and repair a refrigerant leak and to
charge the unit:
1. Locate leak and make sure that refrigerant system pressure
has been relieved and reclaimed from both high-- and
low--pressure ports.
2. Repair leak following accepted practices.
NOTE: Install a filter drier whenever the system has been opened
for repair.
3. Add a small charge of R--22 refrigerant vapor to system and
leak--test unit.
4. Recover refrigerant from system and evacuate to 500
microns if no additional leaks are found.
5. Charge unit with R--22 refrigerant, using a volumetric
charging cylinder or accurate scale. Refer to unit rating plate
for required charge. Be sure to add extra refrigerant to
compensate for internal volume of filter drier.
START--UP
COOLING
ADJUSTMENTS
SECTION
AND
An accurate superheat, thermocouple-- or thermistor--type
thermometer, and a gauge manifold are required when using the
superheat charging method for evaluating the unit charge. Do not
use mercury or small dial--type thermometers because they are not
adequate for this type of measurement.
NOTE: Allow system to operate for a minimum of 10 minutes
before checking or adjusting refrigerant charge.
IMPORTANT: When evaluating the refrigerant charge, an
indicated adjustment to the specified factory charge must always be
very minimal. If a substantial adjustment is indicated, an abnormal
condition exists somewhere in the cooling system, such as
insufficient airflow across either coil or both coils.
Proceed as follows:
1. Remove caps from low-- and high--pressure service fittings.
2. Using hoses with valve core depressors, attach low-- and
high--pressure gauge hoses to low-- and high--pressure
service fittings, respectively.
3. Start unit and let run until system pressures stabilize.
MAKE
4. Measure and record the following:
a. Outdoor ambient--air temperature (°F db).
Complete the required procedures given in the Pre--Start--Up
section before starting the unit. Do not jumper any safety devices
when operating the unit. Do not operate the unit when the outdoor
temperature is below 40°F (unless accessory low--ambient kit is
installed). Do not rapid cycle the compressor. Allow 5 minutes
between “on” cycles to prevent compressor damage.
CHECKING COOLING CONTROL OPERATION
Start and check the unit for proper cooling control operation as
follows:
1. Place room thermostat SYSTEM switch in OFF position.
Observe that blower motor starts when FAN switch is placed
in ON position and shuts down after 30 second fan time
delay expires when FAN switch is placed in AUTO position.
2. Place SYSTEM switch in COOL position and FAN switch
in AUTO position. Set cooling control below room
temperature. Observe that compressor, condenser fan, and
evaporator blower motors start. Observe that compressor
and outdoor fan shut down when control setting is satisfied
and that indoor blower shuts down after 30 second fan time
delay expires.
IMPORTANT: Three--phase, scroll compressors are direction
oriented. Unit must be checked to ensure proper compressor
3--phase power lead orientation. If not corrected within 5 minutes,
the internal protector will shut off the compressor. The 3--phase
power leads to the unit must be reversed to correct rotation. When
turning backwards, the difference between compressor suction and
discharge pressures may be dramatically lower than normal.
b. Suction--tube temperature (°F) at low--side service fitting.
c. Suction (low--side) pressure (psig).
5. Using Cooling Charging Charts compare outdoor--air
temperature (°F db) with the suction line pressure (psig) to
determine desired system operating suction line temperature
(See Fig. 16).
6. Compare actual suction--tube temperature with desired
suction--tube temperature. Using a tolerance of ±3°F, add
refrigerant if actual temperature is more than 3°F higher than
proper suction--tube temperature, or remove refrigerant if
actual temperature is more than 3°F lower than required
suction--tube temperature.
NOTE: If the problem causing the inaccurate readings is a
refrigerant leak, refer to Check for Refrigerant Leaks section.
INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTS
NOTE: For cooling operation, the recommended airflow is 350 to
450 cfm for each 12,000 Btuh of rated cooling capacity.
Table 3 shows cooling airflows at various external static pressures.
Refer to this table to determine the airflow for the system being
installed.
NOTE: Be sure that all supply-- and return--air grilles are open, free
from obstructions, and adjusted properly.
!
CHECKING AND ADJUSTING REFRIGERANT CHARGE
WARNING
ELECTRICAL SHOCK HAZARD
The refrigerant system is fully charged with R--22 refrigerant and
is tested and factory sealed.
Failure to follow this warning could result in personal injury
or death.
NOTE: Adjustment of the refrigerant charge is not required unless
the unit is suspected of not having the proper R--22 charge.
Disconnect electrical power to the unit and install lockout tag
before changing blower speed.
A superheat charging chart is attached to the outside of the service
access panel. The chart includes the required suction line
temperature at given suction line pressures and outdoor ambient
temperatures.
11
50SD
START--UP
Table 3—Wet Coil Air Delivery* — Horizontal Discharge
(Deduct 10% for 208--Volt Operation)
230 VOLT HORIZONTAL DISCHARGE
UNIT
SIZE
MOTOR
SPEED
Low
024
Med
High
Low
030
Med
50SD
High
Low
036
Med
High
Low
042
Med
High
Low
048
Med
High
Low
060
Med
High
AIR
DELIVERY
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
Watts
CFM
0.1
311
935
—
—
—
—
311
935
411
1195
—
—
437
1353
—
—
—
—
625
1539
—
—
—
—
627
1550
771
1798
—
—
786
2027
873
2095
1012
2184
0.2
309
885
—
—
—
—
309
885
405
1155
—
—
433
1318
—
—
—
—
606
1496
741
1738
—
—
617
1530
755
1771
—
—
769
1960
849
2026
993
2109
0.3
304
820
—
—
—
—
304
820
398
1100
—
—
424
1283
—
—
—
—
586
1466
715
1698
—
—
607
1493
734
1734
908
2000
754
1901
833
1962
981
2036
EXTERNAL STATIC PRESSURE (IN. WC)
0.4
0.5
0.6
0.7
301
286
—
—
757
686
—
—
—
379
357
357
—
957
868
769
—
—
—
447
—
—
—
970
301
—
—
—
757
—
—
—
390
379
357
357
1028
957
868
769
—
477
467
447
—
1185
1088
970
417
403
391
379
1235
1187
1123
1059
531
516
496
478
1489
1437
1362
1289
—
—
—
—
—
—
—
—
571
550
534
509
1437
1387
1330
1264
694
669
645
610
1653
1604
1538
1457
—
—
798
772
—
—
1720
1648
584
567
548
528
1461
1414
1361
1320
711
690
665
639
1687
1645
1595
1530
887
858
827
804
1994
1876
1811
1735
736
722
705
684
1821
1759
1693
1616
815
798
782
763
1887
1817
1748
1679
963
948
927
904
1963
1886
1812
1729
0.8
—
—
345
647
435
853
—
—
—
—
435
853
362
975
459
1208
629
1470
483
1183
573
1362
738
1540
503
1250
607
1449
767
1647
658
1513
748
1583
886
1647
0.9
—
—
327
365
421
712
—
—
—
—
—
—
—
—
435
1099
602
1357
457
1093
544
1271
700
1414
—
—
572
1355
748
1555
—
—
—
—
—
—
1.0
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
*Air delivery values are based on operating voltage of 230v, wet coil, without filter or electric heater. Deduct filter and electric heater pressure drops to obtain
static pressure available for ducting.
NOTES:
1. Do not operate the unit at a cooling airflow that is less than 350 cfm for each 12,000 Btuh of rated cooling capacity. Evaporator coil frosting may occur at airflows below this point.
2. Dashes indicate portions of table that are beyond the blower motor capacity or are not recommended.
12
50SD
A05112
Fig. 13 -- Wiring Diagram 208/230--1--60
13
50SD
A06307
Fig. 14 -- Wiring Diagram 208/230--3--60
14
50SD
A06485
Fig. 15 -- Wiring Diagram 460--3--60
15
50SD
A05109
Fig. 16 -- Cooling Charging Chart
Airflow can be changed by changing the lead connections of the
blower motor.
All 50SD units are factory wired for low speed, except sizes 030 and
048 which are wired for medium speed.
FOR 208/230v
For color coding on the 208/230v motor leads, see Table 4.
Table 4—Color Coding for 208/230v Motor Leads
Black = High Speed
Blue = Medium Speed
Red = Low Speed
To change the speed of the indoor fan motor (IFM), remove the fan
motor speed leg lead from the time delay relay (TDR). This wire is
attached to terminal--3 of TDR for 3--phase units. To change the
speed, remove and replace with lead for desired blower motor speed.
Insulate the removed lead to avoid contact with chassis parts.
The normally open contacts of energized contactor (C) close and
complete the circuit through compressor motor (COMP) to
condenser (outdoor) fan motor (OFM). Both motors start instantly.
The set of normally open contacts of energized relay TDR close and
complete the circuit through evaporator blower (indoor) fan motor
(IFM).
NOTE: Once the compressor has started and then has stopped, it
should not be started again until 5 minutes have elapsed.
The cooling cycle remains on until the room temperature drops to
a point that is slightly below the cooling control setting of the room
thermostat. At this point, the thermostat breaks the circuit between
thermostat terminal R to terminals Y and G. These open circuits
deenergize contactor coil C and relay coil TDR. The condenser and
compressor motors stop. After a 30--second delay, the blower motor
stops. The unit is in a standby condition, waiting for the next call for
cooling from the room thermostat.
COOLING SEQUENCE OF OPERATION
With the room thermostat SYSTEM switch in the COOL position
and the FAN switch in the AUTO position, the cooling sequence of
operation is as follows:
When the room temperature rises to a point that is slightly above the
cooling control setting of the thermostat, the thermostat completes
the circuit between thermostat terminal R to terminals Y and G.
These completed circuits through the thermostat connect contactor
coil (C) (through unit wire Y) and time delay relay (TDR) (through
unit wire G) across the 24--v secondary of transformer (TRAN).
MAINTENANCE
To ensure continuing high performance, and to minimize the
possibility of premature equipment failure, periodic maintenance
must be performed on this equipment. This cooling unit should be
inspected at least once each year by a qualified service person. To
troubleshoot unit, refer to Table 5, Troubleshooting Chart.
NOTE TO EQUIPMENT OWNER: Consult your local dealer
about the availability of a maintenance contract.
16
!
WARNING
For longer life, operating economy, and continuing efficiency, clean
accumulated dirt and grease from the blower wheel and motor
annually.
PERSONAL INJURY AND UNIT DAMAGE HAZARD
!
Failure to follow this warning could result in personal injury
or death and possible unit component damage.
WARNING
ELECTRICAL SHOCK HAZARD
The ability to properly perform maintenance on this
equipment requires certain expertise, mechanical skills, tools
and equipment. If you do not possess these, do not attempt to
perform any maintenance on this equipment, other than those
procedures recommended in the Owner’s Manual.
Failure to follow this warning could result in personal injury
or death.
Disconnect and tag electrical power to the unit before cleaning
and lubricating the blower motor and wheel.
To clean the blower motor and wheel:
WARNING
1. Remove and disassemble blower assembly as follows:
a. Remove unit access panel.
ELECTRICAL SHOCK HAZARD
b. Disconnect motor lead from time delay relay (TDR).
Disconnect yellow lead from terminal L2 of the contactor.
Failure to follow these warnings could result in personal
injury or death:
c. On all units remove blower assembly from unit. Remove
screws securing blower to blower partition and slide
assembly out. Be careful not to tear insulation in blower
compartment.
1. Turn off electrical power to the unit before performing any
maintenance or service on this unit.
2. Use extreme caution when removing panels and parts.
d. Ensure proper reassembly by marking blower wheel and
motor in relation to blower housing before disassembly.
3. Never place anything combustible either on or in contact
with the unit.
!
e. Loosen setscrew(s) that secures wheel to motor shaft,
remove screws that secure motor mount brackets to
housing, and slide motor and motor mount out of
housing.
CAUTION
2. Remove and clean blower wheel as follows:
UNIT OPERATION HAZARD
a. Ensure proper reassembly by marking wheel orientation.
Failure to follow this caution may result in equipment damage
or improper operation.
b. Lift wheel from housing. When handling and/or cleaning
blower wheel, be sure not to disturb balance weights
(clips) on blower wheel vanes.
Errors made when reconnecting wires may cause improper
and dangerous operation. Label all wires prior to
disconnecting when servicing.
c. Remove caked--on dirt from wheel and housing with a
brush. Remove lint and/or dirt accumulations from wheel
and housing with vacuum cleaner, using soft brush
attachment. Remove grease and oil with mild solvent.
The minimum maintenance requirements for this equipment are as
follows:
d. Reassemble wheel into housing.
1. Inspect air filter(s) each month. Clean or replace when
necessary.
e. Reassemble motor into housing. Be sure setscrews are
tightened on motor shaft flats and not on round part of
shaft.
2. Inspect indoor coil, drain pan, and condensate drain each
cooling season for cleanliness. Clean when necessary.
f. Reinstall unit access panel.
3. Inspect blower motor and wheel for cleanliness each cooling
season. Clean when necessary.
4. Check electrical connections for tightness and controls for
proper operation each cooling season. Service when
necessary.
5. Ensure electric wires are not in contact with refrigerant
tubing or sharp metal edges.
AIR FILTER
IMPORTANT: Never operate the unit without a suitable air filter
in the return--air duct system. Always replace the filter with the same
dimensional size and type as originally installed. See Table 1 for
recommended filter sizes.
Inspect air filter(s) at least once each month and replace
(throwaway--type) or clean (cleanable--type) at least twice during
each cooling season and twice during the heating season, or
whenever the filter becomes clogged with dust and lint.
INDOOR BLOWER AND MOTOR
NOTE: All motors are pre--lubricated. Do not attempt to lubricate
these motors.
3. Restore electrical power to unit. Start unit and check for
proper blower rotation and motor speeds during cooling
cycles.
OUTDOOR COIL, INDOOR COIL, AND CONDENSATE
DRAIN PAN
Inspect the condenser coil, evaporator coil, and condensate drain
pan at least once each year.
The coils are easily cleaned when dry; therefore, inspect and clean
the coils either before or after each cooling season. Remove all
obstructions, including weeds and shrubs, that interfere with the
airflow through the condenser coil.
Straighten bent fins with a fin comb. If coated with dirt or lint, clean
the coils with a vacuum cleaner, using the soft brush attachment. Be
careful not to bend the fins. If coated with oil or grease, clean the
coils with a mild detergent and water solution. Rinse coils with clear
water, using a garden hose. Be careful not to splash water on motors,
insulation, wiring, or air filter(s). For best results, spray condenser
coil fins from inside to outside the unit. On units with an outer and
inner condenser coil, be sure to clean between the coils. Be sure to
flush all dirt and debris from the unit base.
17
50SD
!
Inspect the drain pan and condensate drain line when inspecting the
coils. Clean the drain pan and condensate drain by removing all
foreign matter from the pan. Flush the pan and drain trough with
clear water. Do not splash water on the insulation, motor, wiring, or
air filter(s). If the drain trough is restricted, clear it with a “plumbers
snake” or similar probe device.
cycle to ensure proper operation. If discrepancies are observed in
operating cycle, or if a suspected malfunction has occurred, check
each electrical component with the proper electrical
instrumentation. Refer to the unit wiring label when making these
checks.
OUTDOOR FAN
Inspect all refrigerant tubing connections and the unit base for oil
accumulation annually. Detecting oil generally indicates a
refrigerant leak.
!
CAUTION
REFRIGERANT CIRCUIT
!
UNIT OPERATION HAZARD
Failure to follow this caution may result in damage to unit
components.
EXPLOSION, PERSONAL INJURY HAZARD
Failure to follow this warning could result in property
damage, personal injury or death.
50SD
Keep the condenser fan free from all obstructions to ensure
proper cooling operation. Never place articles on top of the
unit.
System under pressure. Relieve pressure and recover all
refrigerant before system repair or final unit disposal. Use all
service ports and open all flow--control devices, including
solenoid valves.
1. Remove 6 screws holding outdoor grille and motor to top
cover.
2. Turn motor/grille assembly upside down on top cover to
expose fan blade.
3. Inspect the fan blades for cracks or bends.
4. If fan needs to be removed, loosen setscrew and slide fan off
motor shaft.
5. When replacing fan blade, position blade so that the hub is
1/8 in. away from the motor end (1/8 in. of motor shaft will
be visible) (See Fig. 12).
6. Ensure that set screw engages the flat area on the motor shaft
when tightening.
7. Replace grille.
ELECTRICAL CONTROLS AND WIRING
Inspect and check the electrical controls and wiring annually. Be
sure to turn off the electrical power to the unit.
Remove access panel to locate all the electrical controls and wiring.
Check all electrical connections for tightness. Tighten all screw
connections. If any smoky or burned connections are noticed,
disassemble the connection, clean all the parts, re--strip the wire end
and reassemble the connection properly and securely.
After inspecting the electrical controls and wiring, replace all the
panels. Start the unit, and observe at least one complete cooling
WARNING
If oil is detected or if low performance is suspected, leak test all
refrigerant tubing using an electronic leak detector, or liquid--soap
solution. If a refrigerant leak is detected, refer to Check for
Refrigerant Leaks section.
If no refrigerant leaks are found and low performance is suspected,
refer to Checking and Adjusting Refrigerant Charge section.
INDOOR AIRFLOW
The cooling airflow does not require checking unless improper
performance is suspected. If a problem exists, be sure that all
supply-- and return--air grilles are open and free from obstructions,
and that the air filter is clean.
METERING DEVICES--ACCURATER PISTON
This metering device is a fixed orifice and is contained in the brass
body in the liquid line feeding the indoor coil.
TROUBLESHOOTING
Refer to the Troubleshooting Chart (Table 5) for troubleshooting
information.
START--UP CHECKLIST
Use the Start--Up Checklist at the back of this manual.
18
Table 5—Troubleshooting Chart
Compressor and outdoor fan
will not start
Compressor will not start but condenser fan
runs
CAUSE
Power failure
Fuse blown or circuit breaker tripped
REMEDY
Call power company
Replace fuse or reset circuit breaker
Defective contactor, transformer, control relay, or high-pressure, loss--of--charge or low--pressure switch
Replace component
Insufficient line voltage
Determine cause and correct
Incorrect or faulty wiring
Check wiring diagram and rewire correctly
User Interface setting too low/too high
Reset UI setting
Faulty wiring or circuit
Loose connections in compressor
Compressor motor burned out, seized, or
internal overload open
Defective run capacitor, overload, or PTC (positive
temperature coefficient) thermistor
One leg of 3--phase power dead
Low input voltage (20 percent low)
Three--phase scroll compressor (size 030-060 unit) has a low pressure differential
Scroll compressor is rotating in the wrong direction
Refrigerant overcharge or undercharge
Compressor cycles (other than normally satisfying) cooling/heating calls
Compressor operates continuously
Defective compressor
Insufficient line voltage
Blocked outdoor coil
Defective run/start capacitor, overload or start relay
Faulty outdoor fan motor or capacitor
Restriction in refrigerant system
Dirty air filter
Unit undersized for load
UI temperature set too low
Low refrigerant charge
Air in system
Excessive head pressure
Outdoor coil dirty or restricted
Dirty air filter
Dirty indoor or outdoor coil
Refrigerant overcharged
Air in system
Head pressure too low
Excessive suction pressure
Suction pressure too low
Indoor or outdoor air restricted or air short--cycling
Low refrigerant charge
Restriction in liquid tube
High heat load
Reversing valve hung up or leaking internally
Refrigerant overcharged
Dirty air filter
Low refrigerant charge
Metering device or low side restricted
Insufficient coil airflow
Temperature too low in conditioned area
Outdoor ambient below 55°F
Filter drier restricted
19
Check wiring and repair or replace
Determine cause
Replace compressor
Determine cause and replace
Replace fuse or reset circuit breaker
Determine cause
Determine cause and correct
Correct the direction of rotation by reversing the
3--phase power leads to the unit
Recover refrigerant, evacuate system, and recharge to capacities shown on rating plate
Replace and determine cause
Determine cause and correct
Determine cause and correct
Determine cause and replace
Replace
Locate restriction and remove
Replace filter
Decrease load or increase unit size
Reset UI setting
Locate leak, repair, and recharge
Recover refrigerant, evacuate system, and recharge
Clean coil or remove restriction
Replace filter
Clean coil
Recover excess refrigerant
Recover refrigerant, evacuate system, and recharge
Determine cause and correct
Check for leaks, repair and recharge
Remove restriction
Check for source and eliminate
Replace valve
Recover excess refrigerant
Replace filter
Check for leaks, repair and recharge
Remove source of restriction
Check filter–replace if necessary
Reset UI setting
Install low--ambient kit
Replace
50SD
SYMPTOM
START-UP CHECKLIST
(Remove and Store in Job File)
I. Preliminary Information
MODEL NO.:_________________________________
SERIAL NO.:__________________________________
DATE:_______________________________________
TECHNICIAN:_________________________________
50SD
II. PRE-START-UP (Insert checkmark in box as each item is completed)
( ) VERIFY THAT ALL PACKING MATERIALS HAVE BEEN REMOVED FROM UNIT
( ) REMOVE ALL SHIPPING HOLD DOWN BOLTS AND BRACKETS PER INSTALLATION INSTRUCTIONS
( ) CHECK ALL ELECTRICAL CONNECTIONS AND TERMINALS FOR TIGHTNESS
( ) CHECK THAT INDOOR (EVAPORATOR) AIR FILTER IS CLEAN AND IN PLACE
( ) VERIFY THAT UNIT INSTALLATION IS LEVEL
( ) CHECK FAN WHEEL, AND PROPELLER FOR LOCATION IN HOUSING/ORIFICE AND SETSCREW TIGHTNESS
III. START-UP
ELECTRICAL
SUPPLY VOLTAGE __________________________________
COMPRESSOR AMPS_________________________________
INDOOR (EVAPORATOR) FAN AMPS___________
TEMPERATURES
OUTDOOR (CONDENSER) AIR TEMPERATURE ___________DB
RETURN-AIR TEMPERATURE ___________DB ___________WB
COOLING SUPPLY AIR ___________DB ___________WB
PRESSURES
REFRIGERANT SUCTION ___________PSIG SUCTION LINE TEMP*___________
REFRIGERANT DISCHARGE ___________PSIG DISCHARGE TEMP†___________
( ) VERIFY REFRIGERANT CHARGE USING CHARGING CHARTS
*Measured at suction inlet to compressor
†Measured at liquid line leaving condenser.
HEATING & COOLING
Copyright 2007 Carrier Corporation
Printed in the U.S.A.
Edition Date: 01/07
Manufacturer reserves the right to change, at any time, specifications and design without notice and without obligation.
20
Catalog No: 50SD---5SI
Replaces: 50SD--- 4SI