Operating instructions | Carrier 50GS Air Conditioner User Manual

50GS, 50GX
Single Packaged Electric Cooling Units
Visit www.carrier.com
Installation, Start-Up, and Operating Instructions
50GS Sizes 018-060, 50GX Sizes 024-060
NOTE: Read the entire instruction manual before starting the
installation.
This symbol → indicates a change since the last issue.
TABLE OF CONTENTS
SAFETY CONSIDERATIONS .....................................................1
Introduction ....................................................................................2
RECEIVING AND INSTALLATION ..........................................2
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 ......................................................................3
INSTALLATION ................................................................3
Connect Condensate Drain .......................................................7
Install Duct Connections ..........................................................7
CONFIGURING UNITS FOR DOWNFLOW (VERTICAL) DISCHARGE ............................................................8
Install Electrical Connection ....................................................9
HIGH-VOLTAGE CONNECTIONS................................10
SPECIAL PROCEDURES FOR 208-V OPERATION ...10
CONTROL VOLTAGE CONNECTIONS.......................10
STANDARD CONNECTION ..........................................10
TRANSFORMER PROTECTION....................................13
METERING DEVICE — ACUTROL DEVICE .............25
LIQUID LINE STRAINER ..............................................25
Troubleshooting............................................................................25
Start-Up Checklist ........................................................................25
NOTE TO INSTALLER — Before the installation, READ THESE
INSTRUCTIONS CAREFULLY AND COMPLETELY. Also,
make sure the User’s Manual and Replacement Guide are left with
the unit after installation.
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment can be
hazardous due to system pressure and electrical components. Only
trained and qualified personnel should install, repair, or service
air-conditioning equipment.
Untrained personnel can perform basic maintenance functions of
cleaning coils and 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. Wear safety glasses and work gloves. Use
quenching cloth for unbrazing operations. Have fire extinguisher
available for all brazing operations. Consult a qualified installer or
service agency for information or assistance. The qualified installer or agency must use only factory-authorized kits or accessories when modifying this product.
PRE-START-UP ..........................................................................13
START-UP ...................................................................................14
CHECK FOR REFRIGERANT LEAKS..........................14
START UP COOLING SECTION AND MAKE ADJUSTMENTS ..............................................................................14
CHECKING COOLING CONTROL OPERATION .......14
CHECKING AND ADJUSTING REFRIGERANT
CHARGE ...........................................................................14
INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTS ..............................................................................18
For 208/230V.....................................................................18
FOR 460-V GE MOTORS................................................18
COOLING SEQUENCE OF OPERATION.....................18
MAINTENANCE.........................................................................18
AIR FILTER......................................................................22
EVAPORATOR BLOWER AND MOTOR.....................22
CONDENSER COIL, EVAPORATOR COIL, AND CONDENSATE DRAIN PAN ..................................................24
CONDENSER FAN ..........................................................24
ELECTRICAL CONTROLS AND WIRING ..................24
REFRIGERANT CIRCUIT...............................................24
EVAPORATOR AIRFLOW .............................................25
C99001
Fig. 1—Unit 50GS and 50GX
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 6
PC 101
Catalog No. 535–00130
Printed in U.S.A.
Form 50GS,GX-4SI
Pg 1
9–03
Replaces: 50GS,GX-3SI
Tab 6 8
SLAB MOUNT
Place the unit on a solid, level concrete pad that is a minimum of
4 in. thick with 2 in. above grade (See Fig. 5B). The slab should
extend approximately 2 in. beyond the casing on all 4 sides of the
unit. Do not secure the unit to the slab except when required by
local codes.
Before performing service or maintenance operations on
system, turn off power to unit. Turn off accessory heater
power switch, if applicable. Electrical shock can cause
personal injury.
GROUND MOUNT
Recognize safety information. This is the safety-alert symbol
.
When you see this symbol in instructions or manuals, be alert to
the potential for personal injury.
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.
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 a hazard
which could result in personal injury or death. CAUTION is used
to identify unsafe practices which would 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.
Step 3—Provide Clearances
The required minimum service clearances are shown in Fig. 2 & 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
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 36
in. above the unit top. The maximum horizontal extension of a
partial overhang must not exceed 48 in. For extended overhangs,
provide a minimum clearance of 48 in.
These instructions cover minimum requirements and conform to
existing national standards and safety codes. In some instances,
these instructions exceed certain local codes and ordinances,
especially those that may not have kept up with changing residential construction practices. We require these instructions as a
minimum for a safe installation.
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.
INTRODUCTION
The 50GS and 50GX units (see Fig. 1) are fully self-contained, and
designed for outdoor installation. See Figs. 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 . Units may be installed
either on a rooftop, ground-level cement slab, or directly on the
ground if local codes permit. (See Fig. 4A for roof curb dimensions.)
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.
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
The unit model number and serial number are stamped on the unit
identification plate. Check this information against shipping papers.
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. wg.
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.
ROOF CURB
Install accessory roof curb in accordance with instructions shipped
with curb (See Fig. 4A). Install insulation, cant strips, roofing, and
flashing. Ductwork must be attached to curb.
Follow all applicable safety codes. Wear safety shoes and work
gloves.
IMPORTANT: The gasketing of the unit to the roof curb is critical
for a watertight seal. Install gasketing material supplied with the
roof curb. Improperly applied gasketing also can result in air leaks
and poor unit performance.
Never stand beneath rigged units or lift over people.
Curb should be level to within 1/4 in. (See Fig. 5A). This is
necessary for unit drain to function properly. Refer to accessory
roof curb installation instructions for additional information as
required.
Never exceed 200 lbs. per bracket lifting force.
2
REQUIRED CLEARANCE TO COMBUSTIBLE MATL.
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]
ELECTRIC HEAT PANEL .................................................................36.00 [914.4]
NEC. REQUIRED CLEARANCES.
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]
REQUIRED CLEARANCE FOR OPERATION AND SERVICING
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] *
*MINIMUM DISTANCES: IF UNIT IS PLACED LESS THAN 304.8 [12.00] FROM
WALL SYSTEM, THEN SYSTEM PERFORMANCE MAYBE COMPROMISE.
C99007
UNIT
ELECTRICAL CHARACTERISTICS
50GS018
50GS024
50GS030
50GS036
50GS042
50GX024
50GX030
50GX036
208/230-1-60
208/230-1-60
208/230-1-60, 208/230-3-60
208/230-1-60, 208/230-3-60, 460-3-60
208/230-1-60, 208/230-3-60, 460-3-60
208/230-1-60
208/230-1-60, 208/230-3-60
208/230-1-60, 208/230-3-60, 460-3-60
UNIT WEIGHT
lb.
254
260
258
268
294
270
291
299
kg
115.2
117.9
117.0
121.6
133.3
122.5
132.0
135.6
UNIT HEIGHT
IN. (MM)
”A”
35.02
35.02
35.02
37.02
35.02
37.02
39.02
35.02
(889.5)
(889.5)
(889.5)
(940.3)
(889.5)
(940.3)
(991.1)
(889.5)
20.0
19.0
19.0
20.0
19.0
18.5
19.5
19.5
CENTER OF GRAVITY
IN. (MM)
X
Y
(508.0)
13.0 (330.2)
15.0
(482.6)
13.0 (330.2)
15.0
(482.6)
14.0 (355.6)
15.0
(508.0)
14.0 (355.6)
13.0
(482.6)
14.0 (355.6)
13.0
(469.9)
14.5 (368.3)
16.0
(495.3)
15.5 (393.7)
17.6
(495.3)
15.25 (387.4)
16.5
Z
(381.0)
(381.0)
(381.0)
(330.2)
(330.2)
(406.4)
(447.0)
(419.1)
Fig. 2— 50GS018-042 and 50GX024-036 Unit Dimensions
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.
Accessory lifting kit is only to be used with Small Packaged
units which have a composite base pan with molded rigging
holds.
INSTALLATION
INSPECTION
1. Position the lifting bracket assembly around the base of the
unit. Leave the top shipping skid on the unit to act as a
spreader bar. Be sure the strap does not twist.
Prior to initial use, and at monthly intervals, all rigging brackets
and straps should be visually inspected for any damage, evidence
3
REQUIRED CLEARANCE FOR OPERATION AND SERVICING
REQUIRED CLEARANCE TO COMBUSTIBLE MATL.
INCHES [mm]
EVAP. COIL ACCESS SIDE............................................................36.00 [914.0]
POWER ENTRY SIDE....................................................................36.00 [914.0]
(EXCEPT FOR NEC REQUIREMENTS)
UNIT TOP .......................................................................................48.00 [1219.2]
SIDE OPPOSITE DUCTS ..............................................................36.00 [914.0]
DUCT PANEL .................................................................................12.00 [304.8] *
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]
ELECTRIC HEAT PANEL .................................................................36.00 [914.4]
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]
C99006
UNIT
50GS048
50GS060
50GX042
50GX048
50GX060
ELECTRICAL CHARACTERISTICS
208/230-1-60,
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,
208/230-3-60,
460-3-60
460-3-60
460-3-60
460-3-60
460-3-60
UNIT WEIGHT
lb.
324
389
321
326
399
kg
145
176
146
148
181
UNIT HEIGHT
IN. (MM)
”A”
38.98 (990.2)
38.98 (990.2)
38.98 (990.2)
38.98 (990.2)
42.98 (1091.1)
20.0
19.0
20.5
19.5
20.5
CENTER OF GRAVITY
IN. (MM)
X
Y
(508.0)
17.0 (432.0)
17.0
(482.6)
16.0 (406.0)
17.0
(520.7)
16.75 (425.5)
16.6
(495.3)
17.6 (447.6)
18.0
(520.7)
16.2 (412.8)
17.6
Z
(432.0)
(432.0)
(421.6)
(457.2)
(447.0)
Fig. 3— 50GS048–060 and 50GX042–060 Unit Dimensions
5. Attach safety straps directly to the field supplied rigging straps
or clevis clip. Do not attach the safety straps to the lifting
brackets.
6. Use the top of the unit as a spreader bar to prevent the rigging
straps from damaging the unit. If the wood top is not available,
use a spreader bar of sufficient length to not damage the unit.
2. Place each of the four (4) metal lifting brackets into the
rigging holds in the composite pan.
3. Tighten the ratchet strap unit tight. Lifting brackets should be
secure in the rigging holds.
4. Attach the clevis or hook of sufficient strength to hole in the
lifting bracket (See Fig. 6).
4
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*
Flashing field
supplied
Wood nailer*
Flashing field
supplied
Roofcurb*
Insulation (field
supplied)
Roofing material
field supplied
Insulation (field
supplied)
Roofing material
field supplied
Duct wo rk
field supplied
Cant strip
field supplied
Roofcurb*
Duct wo rk
field supplied
Cant strip
field supplied
Roof
Roof
*Provided with roofcurb
*Provided with roofcurb
Roof Curb for Small Cabinet
Roof Curb for
Note A: When unit mounting scre w is used
,
retainer bracke t must also be used.
Large Cabinet
Note A: When unit mounting scre w is used
,
retainer bracket must also be used.
Supply opening
(B x C)
B Typ.
44 5/ 16"
D
CTyp.
R/A
S/A
A
Insulated
deck pan
Gasket around
duct
Insulated
deck pan
Short
Support
Gasket around
outer edge
Long
Support
Return opening
(B X C)
C00076
UNIT SIZE
50GS018-042
50GX024-036
50GS048-060
50GX042-060
A
IN. (MM)
8 (203)
14 (356)
8 (203)
14 (356)
ODS CATALOG NUMBER
CPRFCURB006A00
CPRFCURB007A00
CPRFCURB008A00
CPRFCURB009A00
B
IN. (MM)
11(279)
11(279)
16-3/16 (411)
16-3/16 (411)
NOTES:
1. Dimensions in ( ) are in millimeters.
2. Roof curb is made of 16-gage steel.
3. Table lists only the dimensions per part number that have changed
4. Insulated panels: 1-in. thick fiberglass 1 lb. density.
Fig. 4A— Roof Curb Dimensions
→
5
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)
1
2
y
4
3
x
C00071
CORNER #
50GS
50GX
018
024
030
036
042
048
060
024
030
036
042
048
060
1
58
60
59
62
76
69
84
76
84
85
71
78
85
2
47
50
48
50
50
45
54
49
60
60
55
56
66
3
55
56
56
58
71
88
106
57
61
64
85
80
108
4
94
94
95
98
97
122
145
88
86
90
110
112
140
TOTAL WEIGHT
254
260
258
268
294
324
389
270
291
299
321
326
399
Fig. 4B—50GS and 50GX Unit Corner Weights
A
C
MAXIMUM ALLOWABLE
DIFFERENCE (in.)
B
A-B
B-C
A-C
1/4
1/4
1/4
C99065
Fig. 5A—Unit Leveling Tolerances
OPTIONAL
RETURN
AIR
OPENING
OPTIONAL
SUPPLY
AIR
OPENING
2"
EVAP. COIL
COND. COIL
C99096
Fig. 5B—Slab Mounting Detail
6
914-137"
(36"-54")
“A”
“B”
DETAIL A
SCALE 0.250
TIGHTEN STRAPPING SECURELY
WITH TENSION BUCKLE
INSTALL SAFETY STRAPS TO
RIGGING CLEVIS AT 4 RIGGING BRACKETS
SEE DETAIL A
SIZE
PLACE RIGGING BRACKET ASSEMBLY IN 4
RIGGING HOLES AND INSTALL TIE DOWN STRAP
AROUND PERIMETER OF UNIT AND THROUGH
SPACE IN BRACKET ASSEMBLY
C99066
MAXIMUM WEIGHT
lb.
kg
018
024
030
036
042
048
060
276
282
280
290
316
346
411
125.2
127.9
127.0
131.5
143.3
156.9
186.4
024
030
036
042
048
060
292
313
321
343
348
421
132.5
142.5
145.6
155.6
157.9
191.0
A
in.
UNIT 50GS
20
19
19
20
19
20
19
UNIT 50GX
18.5
19.5
19.5
20.5
19.5
20.5
B
mm.
in.
mm.
508.0
482.6
482.6
508.0
482.6
508
482.6
13
13
14
14
14
17
16
330.2
330.2
355.6
355.6
355.6
431.8
406.4
469.9
495.3
495.3
520.7
495.3
520.7
14.50
15.50
15.25
16.75
17.62
16.25
368.3
393.7
387.4
425.5
447.6
412.8
Fig. 6—Suggested Rigging
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 drain tube for leaks. Prime trap at the beginning of the
cooling season start-up.
Step 7—Install Duct Connections
The unit has duct flanges on the supply- and return-air openings on
the side and bottom of the unit. For downshot applications the
ductwork can be connected to the roof curb. See Fig. 2 & 3 for
connection sizes and locations.
IMPORTANT: Use flexible connectors between ductwork and
unit to prevent transmission of vibration. Use suitable gaskets to
ensure weathertight and airtight seal. When electric heat is
installed, use fire proof 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 the unit discharge connection flange into the ductwork.
Lifting point should be directly over the center of gravity for
the unit.
Step 6—Connect Condensate Drain
NOTE: When installing condensate drain connection be sure to
comply with local codes and restrictions.
Models 50GS and 50GX dispose 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.
Condensate water can be drained directly onto the roof in rooftop
installations (where permitted) or onto a gravel apron in groundlevel 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 drainpan
condensate connection to prevent the pan from overflowing (See
Fig. 7). When using a gravel apron, make sure it slopes away from
the unit.
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.
7
Table 1—Physical Data—Unit 50GS
UNIT SIZE
NOMINAL CAPACITY (ton)
OPERATING WEIGHT (lb.)
COMPRESSOR
REFRIGERANT (R-22)
Quantity (lb.)
REFRIGERANT METERING DEVICE
Orifice ID (in.)
CONDENSER COIL
Rows...Fins/in.
Face Area (sq. ft.)
CONDENSER FAN
Nominal Cfm
Diameter
Motor Hp (Rpm)
EVAPORATOR COIL
Rows...Fins/in.
Face Area (sq. ft.)
EVAPORATOR BLOWER
Nominal Airflow (Cfm)
Size (in.)
Motor HP (RPM)
RETURN-AIR FILTERS (in.)*
Throwaway
018
1-1/2
254
024
2
260
030
2-1/2
258
Reciprocating
036
3
268
042
3-1/2
294
048
4
324
Scroll
060
5
389
Reciprocating
2.6
3.5
3.65
4.4
6.4
5.1
7.4
.034
.034
.034
Accurater
.032
.034
.032
.030
1...17
6.1
1...17
9.1
1...17
9.1
1...17
10.9
1...17
9.1
1...17
12.3
2...17
12.3
2000
22
1/8 (825)
2400
22
1/8 (825)
2400
22
1/8 (825)
3000
18
1/4 (1100)
3000
22
1/4 (1100)
3600
22
1/4 (1100)
3600
22
1/4 (1100)
2...15
3.1
2...15
3.1
2...15
3.7
3...15
3.06
4...15
3.06
3...15
4.7
4...15
4.7
600
10x10
1/4 (825)
800
10x10
1/4 (1075)
1000
10x10
1/4 (1075)
1200
11x10
1/2 (1075)
1400
11x10
3/4 (1075)
1600
11x10
3/4 (1075)
2000
11x10
1.0 (1100)
20x20
20x20
20x20
20x24
20x24
24x30
24x30
* 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./min. for throwaway type or 450 ft./min. for high-capacity type. Air filter pressure drop for non-standard filters must not exceed 0.08 in. wg.
Table 2—Physical Data—Unit 50GX
UNIT SIZE
NOMINAL CAPACITY (ton)
OPERATING WEIGHT (lb.)
COMPRESSOR
REFRIGERANT (R-22)
Quantity (lb.)
REFRIGERANT METERING DEVICE
Orifice ID (in.)
CONDENSER COIL
Rows...Fins/in.
Face Area (sq. ft.)
CONDENSER FAN
Nominal Cfm
Diameter (in.)
Motor Hp (Rpm)
EVAPORATOR COIL
Rows...Fins/in.
Face Area (sq. ft.)
EVAPORATOR BLOWER
Nominal Airflow (Cfm)
Size (in.)
Motor Hp (RPM)
RETURN-AIR FILTERS (in.)*
Throwaway
024
2
270
030
2-1/2
291
036
3
299
042
3-1/2
321
048
4
326
060
5
399
7.6
8.3
8.1
Scroll
3.7
4.4
5.2
.034
.030
.032
.034
.034
.032
1...17
10.8
1...17
12.7
2...17
9.1
2...17
9.1
2...17
12.3
2...17
16.4
2350
22
1/8 (825)
2350
22
1/8 (825)
2350
22
1/8 (825)
3300
22
1/4 (1100)
3300
22
1/4 (1100)
3300
22
1/4 (1100)
3...15
3.1
3...15
3.1
3...15
3.7
3...15
4.7
4...15
4.7
4...15
4.7
800
10x10
1/4 (1075)
1000
10x10
1/4 (1075)
1200
11x10
1/2 (1075)
1400
11x10
3/4 (1075)
1600
11x10
3/4 (1075)
1750
11x10
1.0 (1040)
20x20
20x20
20x24
20x30
24x30
24x30
Accurater
*
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./min. for throwaway type or 450 ft./min. for high-capacity type. Air filter pressure drop for non-standard filters must not exceed 0.08 in. wg.
CONFIGURING UNITS FOR DOWNFLOW (VERTICAL) DISCHARGE
Before performing service or maintenance operations on the
system, turn off main power to unit and install lockout tag or
electrical shock could result.
1. Open all electrical disconnects and install lockout tag before
starting any service work.
8
2. Remove return duct cover located on duct panel by breaking
four (4) connecting tabs with screwdriver and a hammer. (Fig.
8 & 9)
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. (Fig. 8 & 9)
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.
1” (25mm) MIN.
TRAP
OUTLET
2” (50mm) MIN.
C99013
Fig. 7—Condensate Trap
Table 3—Minimum Airflow for Safe Electric Heater
Operation (Cfm)
018
700
024
800
030
1000
SIZE
036
1200
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.
6. Cover both horizontal duct openings with the duct covers from
the accessory duct cover kit. Ensure opening is air-and
watertight.
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:
8. Units are shipped for side shot installation.
9. Select and size ductwork, supply-air registers, and return-air
grilles according to American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) recommendations.
10. 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 weathertight and airtight seal.
11. 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 Tables 1 and 2.
12. 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.
13. 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.
14. Flash, weatherproof, and vibration-isolate all openings in
building structure in accordance with local codes and good
building practices.
042
1400
048
1600
SUPPLY
DUCT
OPENING
060
2000
RETURN
DUCT
OPENING
C99011
Fig. 8—Supply and Return Duct Opening
Step 8—Install Electrical Connection
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 lug
in the control compartment, or conduit approved for electrical
ground when installed in accordance with NEC (National
Electrical Code) ANSI/NFPA (latest edition) and local electrical codes. In Canada, follow Canadian Electrical Code
CSA (Canadian Standards Association) C22.1 and local
electrical codes. Failure to adhere to this warning could result
in personal injury or death.
9
4. Connect L2 to pressure lug connection 23 of the compressor
contactor.
Three phase units:
1. Run the high-voltage (L1, L2, L3) and ground leads into the
control box.
2. Connect ground lead to chassis ground connection.
3. Locate the black and yellow wires connected to the lines side
of the contactor.
4. Connect field L1 to black wire on connection 11 of the
compressor contactor.
5. Connect field wire L2 to yellow wire on connection 13 of the
compressor contactor.
6. Connect field wire L3 to Blue wire from compressor.
SPECIAL PROCEDURES FOR 208-V OPERATION
Make sure that the power supply to the unit is switched OFF
and lockout tag installed before making any wiring changes.
Electrical shock can cause serious injury or death.
DUCT COVERS REMOVED
C99012
Fig. 9—Vertical Duct Cover Removed
CONTROL VOLTAGE CONNECTIONS
Failure to follow these precautions could result in damage to
the unit being installed:
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.
2. Use only copper conductor for connections between
field-supplied electrical disconnect switch and unit. DO
NOT USE ALUMINUM WIRE.
3. Be sure that high-voltage power to unit is within operating
voltage range indicated on unit rating plate.
4. Do not damage internal components when drilling through
any panel to mount electrical hardware, conduit, etc. On
3-phase units, ensure phases are balanced within 2 percent.
Consult local power company for correction of improper
voltage and/or phase imbalance.
HIGH VOLTAGE
POWER LEADS
(SEE UNIT WIRING
LABEL)
POWER
SUPPLY
GND
FIELD-SUPPLIED
FUSED DISCONNECT
CONTROL BOX
YEL(Y)
GRN(G)
LOW-VOLTAGE
POWER LEADS
(SEE UNIT
WIRING LABEL)
RED(R)
BRN(C)
Y
G
THERMOSTAT
(TYPICAL)
R
C
SPLICE BOX
LEGEND
Field Control-Voltage Wiring
Field High-Voltage Wiring
NOTE: Use blue wire for 3-phase units only.
HIGH-VOLTAGE CONNECTIONS
The unit must have a separate electrical service with a fieldsupplied, waterproof, disconnect switch mounted at, or within
sight from, the unit. Refer to the unit rating plate for maximum
fuse/circuit breaker size and minimum circuit amps (ampacity) for
wire sizing. See Tables 4 and 5 for electrical data.
C99010
Fig. 10—High- and Control-Voltage Connections
NOTE: Do not use any type of power-stealing thermostat. Unit
control problems may result.
The field-supplied disconnect switch box 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 & 3 for acceptable
location.
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.
See unit wiring label and Fig. 10 for reference when making high
voltage connections. Proceed as follows to complete the highvoltage connections to the unit.
Single phase units:
STANDARD CONNECTION
1. Run the high-voltage (L1, L2) and ground leads into the
control box.
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.
2. Connect ground lead to chassis ground connection.
3. Connect L1 to pressure lug connection 11 of the compressor
contactor.
10
Table 4—Electrical Data—50GS
UNIT 50GS
SIZE
V-PH-HZ
VOLTAGE
RANGE
COMPRESSOR
OFM
IFM
Min
RLA
FLA
FLA
Nominal Kw*
FLA
MCA
Max Fuse orCkt Bkr
MOCP
-/18.1/20.8
26.0/30.0
36.1/41.7
13.9/13.9
24.8/28.3
34.7/39.8
47.4/54.3
20/20
25/30
35/40
50/60
—
—
—
—
Max
LRA
ELECTRIC HEAT
POWER SUPPLY
018
208/230–1–60
187
254
9
45
0.8
1.8
-/3.8/5.0
5.4/7.2
7.5/10.0
024
208/230–1–60
187
254
12.8
61
0.8
2
-/3.8/5.0
5.4/7.2
7.5/10.0
-/18.1/20.8
2/30
36.1/41.7
18.8/18.8
25.1/28.5
35/40
47.6/54.6
25/25
25/30
35/40
50/60
—
—
—
—
-/18.1/20.8
26.0/30.0
36.1/41.7
54.2/62.5
20.8/20.8
25.1/28.5
35/40
47.6/54.6
70.2/80.6
25/25
25/30
35/40
50/60
—
—
—
—
—
80/90
208/230–1–60
187
254
14.4
73
0.8
2
-/3.8/5.0
5.4/7.2
7.5/10.0
11.3/15.0
208/230–3–60
187
254
8.3
68
0.8
2
-/3.8/5.0
7.5/10.0
11.3/15.0
-/10.4/12 .0
20.8/24.1
31.3/36.1
13.2/13.2
15.5/17.5
28.6/32.6
41.6/47.6
20/20
20/20
30/35
45/50
—
—
—
—
-/18.1/20.8
26.0/30.0
36.1/41.7
54.2/62.5
24.3/24.3
27.7/31.2
37.6/42.6
50.3/57.2
72.8/83.3
30/30
30/35
40/45
60/60
–
—
—
—
—
80/90
030
036
208/230–1–60
187
254
15.0
82
1.4
4.1
-/3.8/5.0
5.4/7.2
7.5/10.0
11.3/15.0
208/230–3–60
187
254
9.0
78
1.4
4.1
-/3.8/5.0
7.5/10.0
11.3/15.0
-/10.4/12.0
20.8/24.1
31.3/36.1
16.8/16.8
18.2/20.2
31.2/35.2
44.2/50.2
20/20
20/20
35/40
45/60
—
—
—
—
460–3–60
414
508
4.5
40
0.8
1.4
5
10
15
6
12
18
7.8
9.3
16.8
24.3
15
15
20
25
—
—
—
—
4
-/3.8/5.0
5.4/7.2
7.5/10.0
11.3/15.0
15.0/20.0
-/18.1/20.8
26.0/30.0
36.1/41.7
54.2/62.5
72.2/83.3
28.7/28.7
28.7/31.0
37.5/42.5
50.1/57.1
72.7/83.1
95.3/109.2
35/35
35/35
40/45
60/60
—
—
—
—
—
—
80/90
100/110
4
-/3.8/5.0
7.5/10.0
11.3/15.0
15.0/19.9
-/10.4/12.0
20.8/24.1
31.3/36.1
41.6/48.0
18.8/18.8
18.8/20.0
31.1/35.1
44.1/50.1
57.0/65.0
25/25
25/25
35/40
45/60
—
—
—
—
—
60/70
2
5
10
15
20
6
12
18
24.1
9.4
10.0
17.5
25.1
32.6
15
15
20
30
35
—
—
—
—
—
5
-/3.8/5.0
5.4/7.2
7.5/10.0
11.3/15.0
15.0/20.0
-/18.1/20.8
26.0/30.0
36.1/41.7
54.2/62.5
72.2/83.3
38.7/38.7
38.7/38.7
38.7/43.8
51.4/58.3
73.9/84.4
96.5/110.4
40/40
40/40
40/45
60/60
—
—
—
—
—
—
80/90
100/125
5
-/3.8/5.0
7.5/10.0
11.3/15.0
15.0/19.9
-/10.4/12.0
20.8/24.1
31.3/36.1
41.6/48.0
25.4/25.4
25.4/25.4
32.3/36.3
45.3/51.4
58.2/66.2
30/30
30/30
35/40
50/60
—
—
—
—
—
60/70
2.3
5
10
15
20
6
12
18
24.1
12.5
12.5
17.9
25.4
32.9
15
15
20
30
35
—
—
—
—
—
6.8
-/3.8/5.0
5.4/7.2
7.5/10.0
11.3/15.0
15.0/20.0
-/18.1/20.8
26.0/30.0
36.1/41.7
54.2/62.5
72.2/83.3
45.0/45.0
45.0/45.0
45.0/46.0
53.6/60.6
76.2/86.6
98.8/112.7
60/60
60/60
45/50
—
—
—
—
—
—
60/70
80/90
100/125
6.8
-/3.8/5.0
7.5/10.0
11.3/15.0
15.0/19.9
-/10.4/12.0
20.8/24.1
31.3/36.1
41.6/48.0
32.2/32.2
32.2/32.2
34.6/38.6
47.6/53.6
60.5/68.5
40/40
35/35
35/35
50/60
—
—
—
—
—
70/70
3.2
5
10
15
20
6
12
18
24
14.9
14.9
19.0
26.6
34.1
20
15
15
30
35
—
—
—
—
—
208/230–1–60
042
208/230–3–60
460–3–60
208/230–1–60
048
208/230–3–60
460–3–60
208/230–1–60
060
208/230–3–60
460–3–60
187
187
414
187
187
414
187
187
414
254
254
508
254
254
508
254
254
508
18.6
10.7
5.3
25.3
14.6
7.3
28.9
18.6
8.5
105
85
42
131
108
48
147
125
66.5
1.4
1.4
0.8
2.1
2.1
1.1
2.1
2.1
1.1
(See legend following Electrical Data charts)
11
Table 5—Electrical Data—50GX
VOLTAGE
RANGE
UNIT 50GX
SIZE
V-PH-HZ
024
208/230–1–60
COMPRESSOR
OFM
IFM
Max
RLA
LRA
FLA
FLA
Nominal Kw*
FLA
MCA
Max Fuse
or
Ckt Bkr
MOCP
187
253
10.9
54.0
0.9
2.0
-/3.8/5.0
5.4/7.2
7.5/10.0
-/18.1/20.8
26.0/30.0
36.1/41.7
16.5/16.5
25.1/28.5
35.0/40.0
47.6/54.6
20/20
30/30
35/40
50/60
—
—
—
—
-/18.1/20.8
26.0/30.0
36.1/41.7
54.2/62.5
19.8/19.8
25.2/28.7
35.1/40.1
47.8/54.7
70.3/80.8
25/25
25/30
40/45
50/60
—
—
—
—
—
80/90
208/230–1–60
187
253
13.5
73.0
0.8
2.1
-/3.8/5.0
5.4/7.2
7.5/10.0
11.3/15.0
208/230–3–60
187
253
9.0
63.0
0.8
2.1
-/3.8/5.0
7.5/10.0
11.3/15.0
-/10.4/12.0
20.8/24.1
31.3/36.1
14.2/14.2
15.7/17.7
28.7/32.7
41.7/47.7
20/20
20/20
30/35
45/50
—
—
—
—
208/230–1–60
187
253
16.7
97.0
0.8
4.1
-/3.8/5.0
5.4/7.2
7.5/10.0
11.3/15.0
-/18.1/20.8
26.0/30.0
36.1/41.7
54.2/62.5
25.8/25.8
27.7/31.2
37.6/42.6
50.3/57.2
72.8/83.3
30/30
30/35
40/45
60/60
—
—
—
—
—
80/90
208/230–3–60
187
253
11.2
75.0
0.8
4.1
-/3.8/5.0
7.5/10.0
11.3/15.0
-/10.4/12.0
20.8/24.1
31.3/36.1
18.9/18.9
18.9/20.2
3102/35.2
44.2/50.2
25/25
25/25
35/40
45/60
—
—
—
—
460–3–60
414
506
5.4
37.5
0.9
1.9
5
10
15
-/6
12
18
9.6
9.9
17.4
24.9
15
15
20
25
—
—
—
—
4.1
-/3.8/5.0
5.4/7.2
7.5/10.0
11.3/15.0
15.0/20.0
-/18.1/20.8
26.0/30.0
36.1/41.7
54.2/62.5
72.2/83.3
28.1/28.1
28.1/31.2
37.6/42.6
50.3/57.2
72.8/83.3
95.4/109.3
35/35
35/35
40/45
60/60
—
—
—
—
—
—
80/90
100/110
4.1
-/3.8/5.0
7.5/10.0
11.3/15.0
15.0/20.0
-/10.4/12.0
20.8/24.1
31.3/36.1
41.7/48.1
21.2/21.2
21.2/21.2
31.2/35.2
44.2/50.2
57.2/65.3
25/25
25/25
35/40
45/60
—
—
—
—
—
60/70
2.0
5
10
15
20
-/6.0
12.0
18.0
24.1
10.5
10.5
17.5
25.1
32.6
15
15
20
30
35
—
—
—
—
—
4.1
-/3.8/5.0
5.4/7.2
7.5/10.0
11.3/15.0
15.0/20.0
-/18.1/20.8
26.0/30.0
36.1/41.7
54.2/62.5
72.2/83.3
34.9/34.9
34.9/34.9
37.6/42.6
50.3/57.2
72.8/83.3
95.4/109.3
45/45
35/35
40/45
60/60
—
—
—
—
—
—
80/90
100/110
4.1
-/3.8/5.0
7.5/10.0
11.3/15.0
15.0/20.0
-/10.4/12.0
20.8/24.1
31.3/36.1
41.7/48.1
21.9/21.9
21.9/21.9
31.2/35.2
44.2/50.2
57.2/65.3
30/30
25/25
35/40
45/60
—
—
—
—
—
60/70
1.9
5
10
15
20
-/6.0
12.0
18.0
24.1
10.8
10.8
17.4
24.9
32.4
15
15
20
25
35
—
—
—
—
—
6.2
-/3.8/5.0
5.4/7.2
7.5/10.0
11.3/15.0
15.0/20.0
-/18.1/20.8
26.0/30.0
36.1/41.7
54.2/62.5
72.2/83.3
43.8/43.8
43.8/43.8
40.2/45.3
52.9/59.8
75.4/85.9
98.0/111.9
60/60
45/45
45/50
60/60
—
—
—
—
—
—
80/90
100/125
6.2
-/3.8/5.0
7.5/10.0
11.3/15.0
15.0/20.0
-/10.4/12.0
20.8/24.1
31.3/36.1
41.7/48.1
29.4/29.4
29.4/29.4
33.8/37.8
46.8/52.9
59.9/67.9
35/35
30/30
30/40
50/60
—
—
—
—
—
60/70
3.2
5
10
15
20
-/6.0
12.0
18.0
24.1
15.4
15.4
19.0
26.6
34.1
20
20
15
30
35
—
—
—
—
—
208/230–1–60
042
208/230–3–60
460–3–60
208/230–1–60
048
208/230–3–60
460–3–60
208/230–1–60
060
POWER SUPPLY
Min
030
036
ELECTRIC HEAT
208/230–3–60
460–3–60
187
187
414
187
187
414
187
187
414
253
253
506
253
253
506
253
253
506
17.9
12.4
6.1
23.4
13.0
6.4
28.8
17.3
9.0
104.0
88.0
44.0
126.0
93.0
46.5
169.0
123.0
62.0
1.6
1.6
0.9
1.5
1.5
0.9
1.6
1.6
0.9
(See legend following Electrical Data charts)
12
EXAMPLE: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
LEGEND
FLA
— Full Load Amps
LRA
— Locked Rotor Amps
MCA
— Minimum Circuit Amps
MOCP — Maximum Overcurrent Protection
RLA
— Rated Load Amps
CKT BKR — Circuit Breaker
452 + 464 + 455
3
1371
=
3
= 457
®
Average Voltage =
NOTES:
1. In compliance with NEC (National Electrical Code) requirements
for multimotor and combination load equipment (refer to NEC
Articles 430 and 440), the overcurrent protective device for the
unit shall be Power Supply fuse . Canadian units may be
fuse or circuit breaker.
2. Minimum wire size is based on 60 C copper wire. If other than
60 C wire is used, or if length exceeds wire length in table,
determine size from NEC.
3. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is greater than 2%. Use the following formula to determine
the percentage of voltage imbalance.
Determine maximum deviation from average voltage.
(AB) 457 452 = 5 v
(BC) 464 457 = 7 v
(AC) 457 455 = 2 v
Maximum deviation is 7 v.
Determine percent of voltage imbalance.
7
% Voltage Imbalance = 100 x
457
= 1.53%
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
% Voltage imbalance
= 100 x
max voltage deviation from average voltage
average voltage
IMPORTANT: If the supply voltage phase imbalance is
more than 2%, contact your local electric utility company
immediately.
C99024
PRE-START-UP
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, and white (See Fig. 10). 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. 10). Secure all cut wires, so that
they do not interfere with operation of unit.
TRANSFORMER PROTECTION
The transformer is of the energy-limiting type. It is set to
withstand a 30-second overload or shorted secondary condition.
Failure to observe the following warnings could result in
serious personal injury:
1. Follow recognized safety practices and wear protective
goggles when checking or servicing refrigerant system.
2. Do not operate compressor or provide any electric power to
unit unless compressor terminal cover is in place and
secured.
3. Do not remove compressor terminal cover until all electrical sources are disconnected.
4. Relieve and recover all refrigerant from system before
touching or disturbing anything inside terminal box if
refrigerant leak is suspected around compressor terminals.
5. Never attempt to repair soldered connection while refrigerant system is under pressure.
6. Do not use torch to remove any component. System
contains oil and refrigerant under pressure. To remove a
component, wear protective goggles and proceed as follows:
a. Shut off electrical power to unit.
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.
Proceed as follows to inspect and prepare the unit for initial
startup:
1. Remove access panel.
2. Read and follow instructions on all WARNING, CAUTION,
and INFORMATION labels attached to, or shipped with, unit.
3. Make the following inspections:
a. Inspect for shipping and handling damages such as broken
lines, loose parts, disconnected wires, etc.
b. Inspect for oil at all refrigerant tubing connections and on
unit base. Detecting oil generally indicates a refrigerant
13
c.
d.
e.
Verify
a.
b.
c.
d.
START UP COOLING SECTION AND MAKE ADJUSTMENTS
leak. Leak test all refrigerant tubing connections using
electronic leak detector, halide torch, or liquid-soap solution. If a refrigerant leak is detected, see Check for
Refrigerant Leaks section.
Inspect all field- and factory-wiring connections. Be sure
that connections are completed and tight.
Ensure electrical wiring does not contact refrigerant tubes
or sharp metal edges.
Inspect coil fins. If damaged during shipping and handling,
carefully straighten fins with a fin comb.
the following conditions:
Make sure that condenser-fan blade is correctly positioned
in fan orifice. Leading edge of condenser-fan blade should
be 1/2 in. maximum from fan orifice (See Fig. 11).
Make sure that air filter(s) is in place.
Make sure that condensate drain trap is filled with water to
ensure proper drainage.
Make sure that all tools and miscellaneous loose parts have
been removed.
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 compressor 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.
3. When using an auto-changeover room thermostat, place both
SYSTEM and FAN switches in AUTO positions. Observe that
unit operates in heating mode when temperature control is set
to “call for heating” (above room temperature) and operates in
cooling mode when temperature control is set to “call for
cooling” (below room temperature).
IMPORTANT: Three-phase, scroll compressor units (50GS048,
50GX030-060) are direction-oriented. These units 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, scroll
compressors emit elevated noise levels, and the difference between
compressor suction and
discharge pressures may be
dramatically lower than normal.
CHECKING AND ADJUSTING REFRIGERANT CHARGE
The refrigerant system is fully charged with R-22 refrigerant,
tested, and factory-sealed.
NOTE: Adjustment of the refrigerant charge is not required
unless the unit is suspected of not having the proper R-22 charge.
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 (See Fig. 15–27).
An accurate superheat, thermocouple- or thermistor-type thermometer, a sling psychrometer, 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 in the cooling mode for a
minimum of 10 minutes before checking or adjusting refrigerant
charge.
START-UP
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.
FAN GRILLE
MOTOR
1/8" MAX BETWEEN
MOTOR AND FAN HUB
1/2˝
MOTOR SHAFT
C99009
Fig. 11—Fan Blade Clearance
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 refrigerant system and evacuate to
500 microns if no additional leaks are not found.
5. Charge unit with R-22 refrigerant, using a volumetriccharging 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.
14
C99003
Fig. 12—Wiring Diagram (208/230-60-1)
15
C99004
Fig. 13—Wiring Diagram (208/230-60-3)
16
C99005
Fig. 14—Wiring Diagram (460-60-3)
17
Table 6—Color Coding for 208/230–V Motor Leads
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.
3-SPEED
black = high speed
blue = medium speed
red = low speed
2-SPEED
black = high speed
red = low speed
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.
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.
FOR 460-V GE MOTORS
For color coding on the 460-v GE motor leads, see Table 7.
3. Start unit in Cooling mode and let unit run until system
pressures stabilize.
Table 7—Color Coding for 460-V GE Motor Leads
3-SPEED
black = high
violet = jumper
orange = medium
red = low
4. Measure and record the following:
a. Outdoor ambient-air temperature (°F db).
b. Evaporator inlet-air temperature (°F wb).
c. Suction-tube temperature (°F) at low-side service fitting.
2-SPEED
black = high
blue = jumper
red = low
d. 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. 15-27.
To change the speed of the indoor fan motor (IFM), remove fan
motor speed lead from the time delay relay (TDR) and replace with
the lead for the desired blower motor speed. The motor speed lead
is attached to terminal–3 of TDR. For low and medium speeds
black must be connected to the jumper wire. Insulate removed lead
end to avoid contact with chassis parts. To select high speed on
460-v GE motors, separate the black female quick connect (QC)
from the jumper lead male quick connect (QC) and connect the
black lead to the BR. Insulate the jumper to avoid contact with any
chassis parts.
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.
COOLING SEQUENCE OF OPERATION
NOTE: If the problem causing the inaccurate readings is a
refrigerant leak, refer to Check for Refrigerant Leaks section.
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:
INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTS
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).
For cooling operation, the recommended airflow is 350 to 450
cfm for each 12,000 Btuh of rated cooling capacity.
Tables 8 and 9 show cooling airflows at various external static
pressures. Refer to these tables to determine the airflow for the
system being installed.
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.
NOTE: Be sure that all supply- and return-air grilles are open,
free from obstructions, and adjusted properly.
The set of normally open contacts of energized relay TDR close
and complete the circuit through evaporator blower (indoor) fan
motor (IFM).
Disconnect electrical power to the unit and install lockout tag
before changing blower speed. Electrical shock can cause
serious injury or death.
NOTE: Once the compressor has started and then has stopped, it
should not be started again until 5 minutes have elapsed.
Airflow can be changed by changing the lead connections of the
blower motor.
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.
Unit 50GS two- or three-speed motors (except size 030) are
factory wired for low speed operation. Unit 50GS030 is factory
wired for medium speed.
All 50GX units are factory wired for low speed and may need to
be wired for medium or high speed in the field.
FOR 208/230V
For color coding on the 208/230V motor leads, see Table 6.
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
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 single-phase and 3-phase
18
Table 8—Wet Coil Air Delivery (Deduct 10 percent for 208v)*
Horizontal and Downflow Discharge
Unit 50GS018-060
Unit
Motor
Speed
Low
018
Med
High
Low
024
Med
High
Low
030
Med
High
Low
036
Med
High
Low
042
Med
High
Low
048
Med
High
Low
060
Med
High
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
Watts
Cfm
Watts
Cfm
Watts
Cfm
0.0
227
1000
287
1150
280
880
380
1136
485
1415
280
880
380
1136
485
1415
1033
2050
1084
2248
-
0.1
212
915
275
1032
275
825
375
1085
475
1332
275
825
375
1085
475
1332
470
1352
675
1387
886
1458
727
1640
853
1860
979
2090
949
2000
1054
2179
-
0.2
196
825
266
963
270
765
365
1010
470
1266
270
765
365
1010
470
1266
458
1257
514
1338
660
1326
855
1406
712
1600
836
1830
959
2048
864
1945
1024
2110
1184
2278
230 AND 460 VOLT
External Static Pressure (in. wg)
0.3
0.4
0.5
0.6
177
165
153
710
530
340
253
242
234
226
807
698
503
250
267
264
262
260
693
600
450
281
360
355
350
344
946
865
787
650
460
455
445
437
1180
1100
1000
900
267
264
262
260
693
600
450
281
360
355
350
344
946
865
787
650
460
455
445
437
1180
1100
1000
900
445
430
415
399
1240
1199
1107
1015
501
487
471
455
1295
1288
1181
1111
646
636
626
614
1385
1268
1196
1159
650
640
630
620
1275
1204
1142
1081
825
795
778
765
1350
1285
1224
1163
1000
950
925
910
1488
1424
1360
1296
700
688
666
644
1575
1505
1450
1390
821
807
782
756
1770
1700
1642
1565
943
927
897
868
1997
1922
1845
1750
836
822
808
772
1905
1880
1820
1775
994
971
955
928
2058
2000
1932
1885
1152
1120
1102
1084
2207
2124
2041
2000
0.7
335
495
430
780
335
495
430
780
384
924
438
968
602
1032
610
995
750
1091
890
1233
622
1300
730
1482
838
1600
737
1695
897
1829
1056
1960
0.8
312
360
415
480
312
360
415
480
422
813
589
948
595
918
735
1013
875
1148
595
1205
699
1385
802
1550
705
1627
867
1740
1029
1856
0.9
385
256
385
256
580
850
718
932
855
1071
569
1145
667
1290
766
1425
674
1530
835
1638
997
1748
1.0
700
870
833
1005
640
1210
730
1380
642
1480
803
1569
965
1645
* Air delivery values are based on operating voltage of 230v or 460v, 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.
inspected at least once each year by a qualified service person. To
troubleshoot heating or cooling of units, refer to tables at the back
of the book.
The following are 50GS Cooling Charging Charts:
The following are 50GX Cooling Charging Charts:
NOTE TO EQUIPMENT OWNER: Consult your local dealer
about the availability of a maintenance contract.
19
Table 9—Wet Coil Air Delivery (Deduct 10 percent for 208v)*
Horizontal and Downflow Discharge
Unit 50GX024-060
Unit
Motor
Speed
Low
024
Med
High
Low
030
Med
High
Low
036
Med
High
Low
042
Med
High
Low
048
Med
High
Low
060
Med
High
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
0.0
281
833
246
910
343
1148
903
2190
-
0.1
282
776
244
806
339
1104
470
1352
625
1540
588
1514
756
1785
898
2158
1002
2389
-
0.2
281
702
243
749
336
1028
458
1257
514
1338
614
1510
577
1543
738
1765
873
2081
978
2291
-
230 AND 460 VOLT
External Static Pressure (in. wg)
0.3
0.4
0.5
0.6
278
276
638
554
375
370
363
357
894
800
754
636
468
457
884
802
241
680
332
328
322
317
958
850
782
645
441
432
421
1102
988
896
445
430
415
399
1240
1199
1107
1015
501
487
471
455
1295
1288
1181
1111
646
636
626
614
1385
1268
1196
1159
605
593
574
549
1473
1396
1348
1288
726
695
661
1648
1593
1530
572
566
556
539
1467
1408
1374
1324
719
699
676
650
1706
1628
1577
1503
896
862
829
1880
1804
1704
842
814
792
777
2026
1958
1866
1822
960
941
914
880
2216
2120
2020
1952
1080
1080
1066
1041
2316
2181
2122
2101
0.7
-
0.8
-
0.9
-
1.0
-
352
518
444
697
410
783
384
924
438
968
602
1032
518
1192
625
1446
790
1616
517
1237
623
1421
800
1547
764
1744
839
1852
1008
2000
431
467
400
529
422
813
589
948
485
1124
591
1352
766
1492
491
1161
596
1357
775
1565
743
1678
798
1727
972
1802
423
397
454
1037
561
1237
7421
1394
572
1298
752
1406
701
1535
764
1617
938
1672
540
1114
713
1283
555
1253
728
1367
618
1377
750
1549
-
* Air delivery values are based on operating voltage of 230v or 460v, 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.
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 User’s Manual. FAILURE
TO HEED THIS WARNING COULD RESULT IN SERIOUS PERSONAL INJURY AND POSSIBLE DAMAGE TO
THIS EQUIPMENT.
Failure to follow these warnings could result in serious
personal injury:
1. Turn off electrical power to the unit and install lockout tag
before performing any maintenance or service on the unit.
2. Use extreme caution when removing panels and parts. As
with any mechanical equipment, personal injury can result
from sharp edges, etc.
3. Never place anything combustible either on, or in contact
with, the unit.
20
C99037
C99039
Fig. 15—Cooling Charging Chart, 50GS018 Units
Fig. 16—Cooling Charging Chart, 50GS024 Units
C99038
C99040
Fig. 18—Cooling Charging Chart, 50GS036 Units
Fig. 17—Cooling Charging Chart, 50GS030 Units
4. Check electrical connections for tightness and controls for
proper operation each heating and cooling season. Service
when necessary.
Errors made when reconnecting wires may cause improper
and dangerous operation. Label all wires prior to disconnection when servicing.
5. Ensure electric wires are not in contact with refrigerant tubing
or sharp metal edges.
The minimum maintenance requirements for this equipment are as
follows:
1. Inspect air filter(s) each month. Clean or replace when
necessary.
2. Inspect indoor coil, drain pan, and condensate drain at least
each cooling season for cleanliness. Clean when necessary.
3. Inspect blower motor and wheel for cleanliness and check
lubrication each heating and cooling season. Clean when
necessary.
21
OUTDOOR TEMP
°F
°C
115
46
105
41
95
85
75
35
29
24
65
55
18
13
45
7
°
C99041
C99042
Fig. 19—Cooling Charging Chart, 50GS042 Units
Fig. 20—Cooling Charging Chart, 50GS048 Units
(024) 60HZ CHARGING CHART
OUTDOOR TEMP
°F
°C
OUTDOOR TEMP
°F
°C
115
105
95
85
75
65
55
45
46
41
35
29
24
18
13
7
115
105
95
46
41
35
85
75
65
55
29
24
18
13
45
7
°
°
C99043
C99044
Fig. 22—Cooling Charging Chart, 50GX024 Units
Fig. 21—Cooling Charging Chart, 50GS060 Units
For longer life, operating economy, and continuing efficiency,
clean accumulated dirt and grease from the blower wheel and
motor annually.
AIR FILTER
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 Tables
1 and 2 for recommended filter sizes.
Disconnect and tag electrical power to the unit before
cleaning the blower motor and wheel. Failure to adhere to this
warning could cause personal injury or death.
Inspect air filter(s) at least once each month and replace
(throwaway-type) or clean (cleanable-type) at least twice during
each heating and cooling season or whenever the filter(s) becomes
clogged with dust and lint.
To clean the blower motor and wheel:
1. Remove and disassemble blower assembly as follows:
EVAPORATOR BLOWER AND MOTOR
a. Remove unit access panel.
NOTE: All motors are prelubricated. Do not attempt to lubricate
these motors.
b. Disconnect motor lead from time delay relay (TDR).
Disconnect yellow lead from terminal L2 of the contactor.
22
(030) 60HZ CHARGING CHART
(036) 60HZ CHARGING CHART
OUTDOOR TEMP
°F
°C
115
46
105
41
95
35
85
75
65
55
13
45
OUTDOOR TEMP
°F
°C
29
115
105
95
85
46
41
35
29
24
75
24
18
65
18
55
13
45
7
7
°
°
C99046
C99045
Fig. 23—Cooling Charging Chart, 50GX030 Units
Fig. 24—Cooling Charging Chart, 50GX036 Units
(042) 60HZ CHARGING CHART
(048) 60HZ CHARGING CHART
OUTDOOR TEMP
°F
°C
115
105
95
85
46
41
35
29
75
24
65
18
55
13
45
7
OUTDOOR TEMP
°F
°C
°
115
105
95
85
75
46
41
35
29
24
65
18
55
45
13
7
°
C99047
C99048
Fig. 26—Cooling Charging Chart, 50GX048 Units
Fig. 25—Cooling Charging Chart, 50GX042 Units
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.
d. Reassemble wheel into housing.
e. Reassemble motor into housing. Be sure setscrews are
tightened on motor shaft flats and not on round part of
shaft.
f. Reinstall unit access panel.
3. Restore electrical power to unit. Start unit and check for
proper blower rotation and motor speeds during heating and
cooling cycles.
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.
d. Ensure proper reassembly by marking blower wheel and
motor in relation to blower housing before disassembly.
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.
2. Remove and clean blower wheel as follows:
a. Ensure proper reassembly by marking wheel orientation.
b. Lift wheel from housing. When handling and/or cleaning
blower wheel, be sure not to disturb balance weights (clips)
on blower wheel vanes.
23
(060) 60HZ CHARGING CHART
OUTDOOR TEMP
°F
°C
115
105
95
85
75
46
41
35
29
24
65
18
55
13
45
7
°
C99049
Fig. 27—Cooling Charging Chart, 50GX060 Units
4. If fan needs to be removed, loosen the setscrew and slide the
fan off the 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).
6. Ensure that setscrew 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 and install lockout
tag.
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, restrip the
wire end and reassemble the connection properly and securely.
After inspecting the electrical controls and wiring, replace the
access panel. Start the unit, and observe at least one complete
heating cycle and one complete cooling cycle to ensure proper
operation. If discrepancies are observed in either or both operating
cycles, 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 checkouts.
NOTE: Refer to the heating and/or cooling sequence of operation
in this publication as an aid in determining proper control
operation
REFRIGERANT CIRCUIT
Inspect all refrigerant tubing connections and the unit base for oil
accumulations annually. Detecting oil generally indicates a refrigerant leak.
CONDENSER COIL, EVAPORATOR 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.
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 tube with
clear water. Do not splash water on the insulation, motor, wiring,
or air filter(s). If the drain tube is restricted, clear it with a
“plumbers snake” or similar probe device. Ensure that the auxiliary
drain port above the drain tube is also clear
CONDENSER FAN
Keep the condenser fan free from all obstructions to ensure
proper cooling operation. Never place articles on top of the
unit. Damage to unit may result.
1. Remove 6 screws holding condenser grille and motor to top
cover.
2. Turn motor/grille assembly upside down on top cover to
expose the fan blade.
3. Inspect the fan blades for cracks or bends.
24
obstructions, and that the air filter is clean. When necessary, refer
to Indoor Airflow and Airflow Adjustments section to check the
system airflow.
System under pressure. Relieve pressure and recover all
refrigerant before system repair or final unit disposal to avoid
personal injury or death. Use all service ports and open all
flow-control devices, including solenoid valves.
METERING DEVICE — ACUTROL DEVICE
This metering device is a fixed orifice and is located in the header
to the evaporator coil.
If oil is detected or if low cooling performance is suspected,
leak-test all refrigerant tubing using an electronic leak-detector,
halide torch, or liquid-soap solution. If a refrigerant leak is
detected, refer to Check for Refrigerant Leaks section.
LIQUID LINE STRAINER
The liquid line strainer (to protect metering device) is made of wire
mesh and located in the liquid line on the inlet side of the metering
device.
If no refrigerant leaks are found and low cooling performance is
suspected, refer to Checking and Adjusting Refrigerant Charge
section.
EVAPORATOR AIRFLOW
TROUBLESHOOTING
Use the Troubleshooting–Cooling guide (see Table 10) if problems
occur with these units.
The heating and/or cooling air-flow 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
START-UP CHECKLIST
Use the Start-Up checklist to ensure proper start-up procedures are
followed.
25
Table 10—Troubleshooting—Cooling
SYMPTOM
Compressor and condenser fan will not start.
Compressor will not start but condenser fan
runs.
Three-phase scroll compressor (50GS048,
50GX030-060) makes excessive noise, and
there may be a low pressure differential.
Compressor cycles
(other than normally satisfying thermostat).
Compressor operates continuously.
Excessive head pressure.
Head pressure too low.
Excessive suction pressure.
Suction pressure too low.
CAUSE
REMEDY
Power Failure
Call power company
Fuse blown or circuit breaker tripped
Replace fuse or reset circuit breaker
Defective thermostat, contractor, transformer, or
control relay
Replace component
Insufficient line voltage
Determine cause and correct
Incorrect or faulty wiring
Check wiring diagram and rewire correctly
Thermostat setting too high
Lower thermostat setting below
room temperature
Faulty wiring or loose connections in compressor
circuit
Check wiring and repair or replace
Compressor motor burned out, seized, or internal
overload open
Determine cause
Replace compressor
Defective run/start capacitor, overload, start relay
Determine cause and replace
One leg of 3-phase power dead
Replace fuse or reset circuit breaker
Determine cause
Scroll compressor is rotating
in the wrong direction
Correct the direction of rotation by reversing the
3-phase power leads to the unit. Shut down unit
to allow pressures to equalize.
Refrigerant overcharge or undercharge
Recover refrigerant, evacuate system, and recharge to capacities shown on nameplate
Defective compressor
Replace and determine cause
Insufficient line voltage
Determine cause and correct
Blocked condenser
Determine cause and correct
Defective run/start capacitor, overload or start
relay
Determine cause and replace
Defective thermostat
Replace thermostat
Faulty condenser-fan motor or capacitor
Replace
Restriction in refrigerant system
Locate restriction and remove
Dirty air filter
Replace filter
Unit undersized for load
Decrease load or increase unit size
Thermostat set too low
Reset thermostat
Low refrigerant charge
Locate leak, repair, and recharge
Leaking valves in compressor
Replace compressor
Air in system
Recover refrigerant, evacuate system, and recharge
Condenser coil dirty or restricted
Clean coil or remove restriction
Dirty air filter
Replace filter
Dirty condenser coil
Clean coil
Refrigerant overcharged
Recover excess refrigerant
Air in system
Recover refrigerant, evacuate system, and recharge
Condenser air restricted or air short-cycling
Determine cause and correct
Low refrigerant charge
Check for leaks, repair and recharge
Compressor valves leaking
Replace compressor
Restriction in liquid tube
Remove restriction
High heat load
Check for source and eliminate
Compressor valves leaking
Replace compressor
Refrigerant overcharged
Recover excess refrigerant
Dirty air filter
Replace Filter
Low refrigerant charge
Check for leaks, repair, and recharge
Metering device or low side restricted
Remove source of restriction
Insufficient evaporator airflow
Increase air quantity
Check filter- replace if necessary
Temperature too low in conditioned area
Reset thermostat
Outdoor ambient below 40°F
Install low-ambient kit
Field-installed filter-drier restricted
Replace
26
START-UP CHECKLIST
(REMOVE AND STORE IN JOB FILE)
I. PRELIMINARY INFORMATION
Model No .............................................................................................................................................................
Serial No ..............................................................................................................................................................
Date .....................................................................................................................................................................
Technician ...........................................................................................................................................................
Job/ Location...............................................................................................................................................
II. PRE-START-UP
____ Verify that all packing materials have been removed from unit
____ Verify that condensate connection is installed 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 propeller for location in housing and setscrew tightness
III. START-UP
Supply Voltage: L1-L2(C-S) __________ L2-L3(S-R) __________ L3-L1(R-C) __________
Compressor Amps: L1(C) __________ L2(S) __________ L3(R) __________
Indoor (Evaporator) Fan Amps: __________
TEMPERATURE
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 tables
____ Verify that 3-phase scroll compressor (50GS048 and 50GX030–060) is rotating in correct direction.
* Measured at suction inlet to compressor
† Measured at liquid line leaving condenser
27
Copyright 2003 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231
50gsgx4si
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 6
PC 101
Catalog No. 535–00130
Printed in U.S.A.
Form 50GS,GX-4SI
Pg 28
9–03
Replaces: 50GS,GX-3SI
Tab 6 8
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