Carrier 50HJ015 Dimensions and installation guide

HEATING & COOLING
50HJ015,024
Single-Package Rooftop Units
Electric Cooling with Electric Heat Option
Installation, Start-Up and Service
Instructions
CONTENTS
Page
SAFETY CONSIDERATIONS . 1
INSTALLATION . 1-9
Step 1 — Provide Unit Support. 1
• ROOF CURB
• ALTERNATE UNIT SUPPORT
Step 2 — Rig and Place Unit . 1
• POSITIONING
• ROOF MOUNT
Step 3 — Field Fabricate Ductwork . 6
Step 4 — Make Unit Duct Connections .... 6
Step 5 — Trap Condensate Drain. 6
Step 6 — Make Electrical Connections . 7
• FIELD POWER SUPPLY
• FIELD CONTROL WIRING
Step 7 — Make Outdoor-Air Inlet
Adjustments. 8
• MANUAL OUTDOOR-AIR DAMPER
• OPTIONAL FACTORY-INSTALLED
ECONOMIZER
Step 8 — Install Outdoor-Air Hood . 8
START-UP. 10-12
SERVICE .12-16
START-UP CHECKLIST. C L-l
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment
can be hazardous due to system pressure and electrical com¬
ponents. Only trained and qualified service personnel should
install, repair, or service air-conditioning equipment.
Untrained personnel can perform basic maintenance func¬
tions of cleaning coils and filters and replacing filters. All
other operations should be performed by trained service
personnel. When working on air-conditioning equipment,
observe precautions in the literature, tags and labels at¬
tached 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 extinguishers available for all brazing operations.
A WARNING
Before performing service or maintenance operations
on unit, turn off main power switch to unit. Electrical
shock could cause personal injury.
INSTALLATION
Step 1 — Provide Unit Support
ROOF CURB — Assemble and install accessory roof curb
in accordance with instructions shipped with the curb.
Accessory roof curb and information required to field
fabricate a roof curb are shown in Fig 1 and 2. Install in¬
sulation, cant strips, roofing, and counter flashing as shown.
Ductwork can be secured to roof curb before unit is set in
place.
IMPORTANT - The gasketing of the unit to the roof
curb is critical for watertightness Install gasket sup¬
plied with the roof curb as shown in Fig. 1. Improp¬
erly applied gasket can result in air leaks and poor
unit performance.
Curb should be level. This is necessary to permit unit
drain to function properly Unit leveling tolerance is
± Vi6 in. per linear ft in any direction. Refer to Accessory
Roof Curb Installation Instructions for additional informa¬
tion as required.
ALTERNATE UNIT SUPPORT - When the curb cannot
be used, support unit with sleepers using unit curb support
area. If sleepers cannot be used, support long sides of unit
with a minimum of 3 equally spaced 4-in. x 4-in. pads on
each side.
Step 2 — Rig and Place Unit — Inspect unit for
transportation damage. File any claim with transportation
agency. Keep unit upright, and do not drop. Use spreader
bars over unit to prevent sling or cable damage. Rollers
may be used to move unit across a roof. Level by using unit
frame as a reference; leveling tolerance is ± Vi6 in. per lin¬
ear ft in any direction. See Fig. 1 for additional leveling
tolerance information. Unit weight is shown in Table 1.
Four lifting holes are provided in ends of unit base rails
as shown in Fig. 3 Refer to rigging instructions on unit.
POSITIONING — Provide clearance around and above unit
for airflow, safety, and service access (Fig. 4).
Do not install unit in an indoor location. Do not locate
air inlets near exhaust vents or other sources of contam¬
inated air.
Although unit is weatherproof, guard against water from
higher level runoff and overhangs.
ROOF MOUNT — Check building codes for weight dis¬
tribution requirements.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1
Tab 1b
PC 111
Catalog No 565-125 Printed in U S A. Form 50HJ-6SI
Pg 1 12-93 Replaces: New

ACCESSORY
PACKAGE NO.
CURB
HEIGHT
DESCRIPTION
50PQ900221
1'-2"
(305)
Standard Curb —
14" High
2'-0"
(610)
Standard Curb
50PQ900141
for Units Requiring
High Installation
50PQ900151
2'-0"
(610)
Horizontal Supply
and Return Curb
LEGEND
COMP SECT. — Compressor Section
NOTES:
1 Roof curb accessory is shipped unassembled.
2. Insulated panels, 1-in thick neoprene-coated,
1 V 2 lb density.
3 Dimensions in ( ) are in millimeters.
4
Direction of airflow.
5 Roof curb 16 gage steel.
Fig. 1 — Roof Curb Details
2

EVAPORATOR- EVAPORATOR-
FAN MOTOR FAN MOTOR
Fig. 2 - Horizontal Supply/Return Curb Details
DIMENSION A
UNIT 50HJ
Ft-in. mm
015
3-0 914
024
3-4 Vfe
1029
NOTES:
1. Dimensions in ( ) are in millimeters
2 Refer to Table 1 for unit operating weights.
3. Remove boards at ends of unit and runners prior to rigging.
4 Rig by inserting hooks into unit base rails as shown. Use corner
post from packaging to protect coil from damage. Use bumper
boards for spreader bars.
5 Weights do not include optional economizer See Table 1 for econo¬
mizer weight.
6. Weights given are for aluminum evaporator coil plate fins and
copper condenser coil plate fins Weights of other metal combi¬
nations are listed in Table 1
A CAUTION
All panels must be in place when rigging.
Fig. 3 - Rigging Details
3

CONTROL 80X
ACCE55
f (8?)
25% AIR OR
ECONOMIZER HOOD
U
FIELD--
SUPPLIED
u
1
O' -3"
(76)
3 7/16*
SECTION A-A
0 -3 7/8
(99)
II
INDOOR COIL
ALTERNATE RETURN
3/4" FPT ORA IN CONNECTION
(27) FAR 5IDE ONLY
DIMENSIONS
-3* 8 7/8'DIA CONCENTRIC < 0
(76) £ (22) (FIELD POWER)
UNIT
A
B C
50HJ
Ft-in. mm Ft-in. mm
Ft-in. mm
015 3-0
914 2-9 838 1-10 559
024 3-4% 1035
3-7
1092 1-8 508
LEGEND
KO — Knockout
NOTES:
1
CORNER WEIGHT*
UNIT
50HJ
A
1_ B _1
C j
D
Lb
Kg
Lb
Kg
Lb
Kg
Lb
Kg
015 390
177
243 110 322 146
515 234
024 492 1
233
511
232
504
229 523 237
‘Weights are for unit only (with aluminum evaporator and condenser
coil fins) and do not include options or crating
Dimensions in ( ) are in millimeters
2 ® Center of gravity.
3<=> Direction of airflow.
4 Ductwork to be attached to accessory roof curb only.
5. Minimum clearance:
a Rear: 7'-0" (2134) for coil removal. This dimension
can be reduced to 4'-0” (1219) if conditions permit
coil removal from the top
b Left side: 4'-0" (1219) for proper condenser coil
airflow
c Front 1 4'-0" (1219) for control box access
d. Right side: 4'-0" (1219) for proper operation of damper
and power exhaust (if so equipped).
e. Top: 6'-0" (1829) to assure proper condenser fan
operation.
f. Local codes or jurisdiction may prevail.
6. With the exception of clearance for the condenser coil
and the damper/power exhaust as stated in note no 5, a
removable fence or barricade requires no clearance
Dimensions are from outside of corner post. Allow
0'- 5 /ie" (8) on each side for top cover drip edge
7.
Fig. 4 — Base Unit Dimensions
4

Table 1 — Physical Data
UNIT SIZE 50HJ
OPERATING WT (lb)
AI/AI*
Unit Al/Cu*
Cu/Cu*
Economizer
Roof Curbt
COMPRESSOR
Number
Oil (oz)152
2030
2160
2270
110
200
REFRIGERANT
Charge (lb)** Sys 1, Sys 2 20 . 8 , -
R-22
16.25, 16.25
REFRIGERANT METERING DEVICE
Upper Circuit
No. ...Length (in.)...lD/OD
Lower Circuit
No. ...Length (in.)...ID/OD
Capillary Tubes
.25...0 055/0.125
25...0 055/0.125
.25...0 055/0.125
13. 25 .0.055/0.125
13...25.. 0.055/0 125
CONDENSER COIL
Rows
Fins/in.
Total Face Area (sq ft)
Copper Tubes, Aluminum or Copper Plate Fins
13 6 Al or 12.4 Cu
18.9
13.6 Al or 12.4 Cu
22 2
CONDENSER FAN
Nominal Cfm
Number...Diameter (in.)
Motor Hp (1075 Rpm)
Watts Input (Total)
12,000
2...26
1
2672
Propeller Type, Direct Drive
11,400
2 .26
1
3000
EVAPORATOR COIL
Rows
Fins/in.
Total Face Area (sq ft)
Copper Tubes, Aluminum or Copper Plate Fins
14.3 Al or 13.1 Cu
16 5
14.4 Al or 13.1 Cu
17.9
EVAPORATOR FAN
Quantity...Size (in.)
Nominal Cfm
Maximum Allowable Rpm
Motor Pulley Pitch Diameter (in.)
Fan Pulley Pitch Diameter (in.)
Belt, Quantity...Type...Length (in.)
Factory Speed Setting (Rpm)
Motor Hp (Service Factor)
Motor Frame Size
2.. 10 x 10
5000
1550
3 4-4.4
6.0
1 .V...41
1092
3 (1.15)
56
Centrifugal, Fixed Pitch Belt Drive
2...12 x 12
8000
1500
6.10
8.40
1. BX,. 51
1287
7V2 (1.15)
184T
HIGH-PRESSURE SWITCH
Cutout (psig)
Reset (psig)_
426
320
LOW-PRESSURE SWITCH
Cutout (psig)
Reset (psig)
7
22
AIR INLET SCREENS
Economizer, Quantity...Size (in.)
20 x 25 x 1
20 x 20 x 1
RETURN-AIR FILTERS (TYPE)
Quantity... Size (in.)
10% Efficient
2.. . 20 x 20 x 2
3.. . 1 6 x 20 x 2
2.. . 1 6 x 25 x 2
2-in Throwaway Fiberglass
4.. 20 x 20 x 2
4.. 16 x 20 x 2
LEGEND
Al — Aluminum
Cu — Copper
*Evaporator coil fin material/condenser coil fin material.
tWeight of 14 in. roof curb.
**System 1 consists of the upper portion of condenser coil and intertwined evaporator coil, and
System 2 consists of the lower portion of the condenser coil and intertwined evaporator coil
NOTE: The 50HJ015 has adjustable pulleys The 50HJ024 has one set (2) of fixed pulleys
5

Step 3 — Field Fabricate Ductwork — Secure all
ducts to building structure. Use flexible duct connectors be¬
tween unit and ducts as required. Insulate and weatherproof
all external ductwork, joints, and roof openings with counter
flashing and mastic in accordance with applicable codes.
Ducts passing through an unconditioned space must be
insulated and covered with a vapor barrier.
The 50HJ units with electric heat require a 1-in. clear¬
ance for the first 24 in. of ductwork.
Outlet grilles must not lie directly below unit discharge.
Step 4 — Make Unit Duct Connections - Unit
is shipped for through-the-bottom duct connections. Duct¬
work openings are shown in Fig. 5. Field-fabricated con¬
centric ductwork may be connected as shown in Fig. 6 and
7. Attach all ductwork to roof curb and roof curb basepans.
Refer to installation instructions shipped with accessory roof
curb for more information.
Step 5 — Trap Condensate Drain — See Fig. 4
and 8 for drain location. Plug is provided in drain hole and
must be removed when unit is operating. One 3 /4-in. half
NOTE. Do not drill in this area, as damage to basepan may result in
water leak.
Fig. 5 — Air Distribution — Through-the-Bottom
(50HJ024 Shown)
NOTE: Do not drill in this area, as damage to basepan may result in
water leak.
Fig. 6 - Concentric Duct Air Distribution
(50HJ024 Shown)
coupling is provided inside unit evaporator section for con¬
densate drain connection. An 8Vi in x 3 A-in. diameter nip¬
ple and a 2-in. x 3 /4-in. diameter pipe nipple are coupled to
standard 3 /4-in. diameter elbows to provide a straight path
down through holes in unit base rails (see Fig. 9). A trap at
least 4-in. deep must be used.
Shaded area indicates block-off panels.
NOTE ^Dimensions A, A' and B, B' are obtained from field-supplied
ceiling diffuser
Fig. 7 - Concentric Duct Details
Fig. 9 — Condensate Drain Piping Details
6

Step 6 — Make Electrical Connections
FIELD POWER SUPPLY — Unit is factory wired for volt¬
age shown on nameplate.
When installing units, provide a disconnect, per NEC
(National Electrical Code) requirements, of adequate size
(Table 2).
All field wiring must comply with NEC and local
requirements.
Route power lines through control box access panel or
unit basepan (Fig. 4) to connections as shown on unit wir¬
ing diagram and Fig. 10.
Transformer no. 1 is wired for 230-v unit. If 208/230-v
unit is to be run with 208-v power supply, the transformer
must be rewired as follows:
1. Remove cap from red (208 v) wire.
2. Remove cap from orange (230 v) spliced wire.
3. Replace orange wire with red wire
4. Recap both wires.
TB1 MAXIMUM WIRE SIZE
UNIT 50HJ
VOLTAGE
208/230 460 575
015 350 kcmil
2/0 2/0
024 350 kcmil
2/0 2/0
IMPORTANT: BE CERTAIN UNUSED WIRES
ARE CAPPED. Failure to do so may damage the
transformers.
Operating voltage to compressor must be within voltage
range indicated on unit nameplate. On 3-phase units, volt¬
ages between phases must be balanced within 2% and the
current must be balanced within 10%.
Use the following formula to determine the percentage of
voltage imbalance.
Percentage of Voltage Imbalance
, ^ max voltage deviation from average voltage
- 100 x - 2 i 2
average voltage
Example: Supply voltage is 460-3-60.
AB =452 v
BC =464 v
AC =455 v
Average Voltage
452 +464 +455
3
1371
~ 3
= 457
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 the percentage of voltage imbalance:
7
Percentage of Voltage Imbalance = 100 x -
LEGEND
EQUIP
— Equipment
GND — Ground
kcmil — Thousand Circular Mils
NEC — National Electrical Code
TB
— Terminal Block
Fig. 10 — Field Power Wiring Connections
FIELD CONTROL WIRING - Install a Carrier-approved
accessory thermostat assembly according to the installation
instructions included with the accessory. Locate thermostat
assembly on a solid wall in the conditioned space to sense
average temperature.
Route thermostat cable or equivalent single leads of
no. 18 AWG (American Wire Gage) colored wire from
subbase terminals through conduit in unit to low-voltage
connections as shown on unit label wiring diagram and in
Fig. 11.
NOTE: For wire runs up to 50 ft, use no. 18 AWG insu¬
lated wire (35 C minimum). For 50 to 75 ft, use no. 16
AWG insulated wire (35 C minimum). For over 75 ft, use
no. 14 AWG insulated wire (35 C minimum). All wire larger
than no. 18 AWG cannot be directly connected to the ther¬
mostat and will require a junction box and splice at the
thermostat.
Set heat anticipator settings as indicated in Table 3. Set¬
tings may be changed slightly to provide a greater degree of
comfort for a particular installation.
Refer to accessory remote control instructions as
required.
= 1.53%
This amount of phase imbalance is satisfactory as it is
below the maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbal¬
ance is more than 2%, contact your local electric util¬
ity company immediately.
Unit failure as a result of operation on improper line volt¬
age or excessive phase imbalance constitutes abuse and may
cause damage to electrical components.
THERMOSTAT ASSEMBLY
REMOVABLE JUMPER
[i^-RC yi j Y 2 J wi jwi] J"gT
[fuix
RED
33
-
Y] (Y 2 J WI W2
\ 8 3 1
BLK
jol
rh rh
c X
Fig. 11 - Field Control Thermostat Wiring
7

Table 2 — Electrical Data
UNIT
50HJ
V-PH-HZ
VOLTAGE
RANGE
COMPRESSOR
CONDENSER
FAN MOTOR
EVAPORATOR
FAN MOTOR
ACCESSORY/OPTIONAL
ELECTRIC HEATERS*
POWER SUPPLY
No. 1 No. 2
Min Max RLA LRA RLA
LRA Qty FLA Hp
FLA
FLA
kW MCA
MOCPf
015
208/230-3-60
187 253 49 3 191
- -
2 77 3 105
39/ 45
72/ 82
117/135
14/19
26/34
42/56
88/ 88
88/ 88
103/116
159/148
100/100
100/100
110/125
175/175
460-3-60 414 508 22 1 86
- -
2 33 3
48
18
39
66
15
32
55
39
39
55
72
45
45
60
80
575-3-60
518
632
179 69
-
-
2 26 3
39
37
37
32
52
35
60
024
208/230-3-60 187
253 43 9 170
43 9
170
2
54
(ea)
7%
24 2/22 0
72/ 82
117/135
156/180“
26/34
42/56
56/75“
134/132
134/132
177/163
186/208“
175/175
175/175
200/175
200/225“
460-3-60
414 508 199
77 19 9 77
2
27
(ea)
7 Vs 11 0
39
66
96“
32
55
80“
62
62
80
110“
80
80
90
110“
575-3-60 518
632
159
62 159 62 2
34
(ea)
7 Vs 9 0
- -
52 60
LEGEND
FLA — Full Load Amps
HACR — Heating, Air Conditioning and Refrigeration
LRA — Locked Rotor Amps
MCA — Minimum Circuit Amps
MOCP — Maximum Overcurrent Protection
NEC — National Electrical Code
RLA — Rated Load Amps
‘Heater capacity' (kW) is based on heater voltage of 208 v, 240 v, 480 v and
575 v. If power distribution voltage to unit varies from rated heater voltage,
heater kW will vary accordingly This is the maximum size permissible; smaller
fuse size may be used where conditions permit
tFuse or HACR circuit breaker
“Heaters are field installed only
NOTES:
1. In compliance with NEC requirements for multimotor and combination load
equipment (refer to NEC Articles 430 and 440), the overcurrent protective
device for the unit shall be fuse or HACR breaker The Canadian units may
be fuse or circuit breaker
2 MCA calculation for units with electric heaters over 50 kW
= (1.25 x IFM amps) + (1 00 x heater FLA).
Table 3 - Heat Anticipator Settings
UNIT
VOLTAGES
kW
STAGE 1
STAGE 2
14/17
40
—
208/230
26/31
40
40
50HJ
42/52 66 40
15 40
—
Ol 5
460
30
40 40
51 40 66
575
37 40 .66
26/31 40
66
208/230,575-3-60 42/52 .66
40
50HJ
56/69
66
66
024
30
40
40
460-3-60
51 40 66
_73_j
66
66
Step 7 — Make Outdoor-Air Inlet
Adjustments
MANUAL OUTDOOR-AIR DAMPER - All units
(except those equipped with a factory-installed economizer)
have a manual outdoor-air damper to provide ventilation
air. Damper can be preset to admit up to 25% outdoor air
into return-air compartment. To adjust, loosen securing screws
and move damper to desired setting Then retighten screws
to secure damper (Fig. 12).
OPTIONAL FACTORY-INSTALLED ECONOMIZER
Economizer Motor Control Module (Fig. 13-15) — Set to
the "D" setting (Fig. 14) The control module is located on
the economizer motor. See Fig. 13 and 15.
Damper Vent Position Setting
1. Set fan switch at ON position (continuous fan operation)
and close night switch if used.
2. Set system selector switch to OFF position.
3. Turn adjustment screw slowly until dampers assume de¬
sired vent position. Do not manually operate econo¬
mizer motor since damage to motor will result.
NOTE: Refer to accessory installation instructions in¬
cluded with the field-installed economizer for installation
information. Also see Accessory Field-Installed Econo¬
mizer Adjustment section on page 10.
Step 8 — Install Outdoor-Air Hood — The same
type of factory-installed hood is used on units with 25% air
ventilation and units with an economizer.
NOTE: The hood top panel, upper and lower filter retain¬
ers, hood drain pan, baffle (024 only), and filter support
bracket are secured opposite the condenser end of the unit.
The screens, hood side panels, remaining section of filter
support bracket, seal strip, and all other hardware are in a
package located inside the return-air filter access panel
(Fig. 16)
1. Attach seal strip to upper filter retainer. See Fig. 17.
2. Assemble hood top panel and side panels, upper filter
retainer, and hood drain pan (Fig. 18)
3. Secure lower filter retainer and long piece of filter sup¬
port bracket to unit. See Fig. 18. Leave screws on 024
units loose
4. 50HJ024 Units Only: Slide baffle behind lower filter re¬
tainer and tighten screws.
5. Loosen sheet metal screws for base unit top panel lo¬
cated above outdoor-air inlet opening.
25% ADJUSTABLE
AIR DAMPER
BASE
UNIT
Fig. 12 — 25% Outdoor-Air Section Details

COOLING
LOCKOUT
SWITCH
ECONOMIZER
MOTOR
ECONOMIZER'
CONTROL
MODULE
FILTERS
ECONOMIZER
damper
assembly
Fig. 13 - Economizer Damper Assembly - End View
LED — Light-Emitting Diode
Fig. 14 — Economizer Control Module
Fig. 15 - Economizer Control Module Location
6 Match notches in hood top panel to unit top panel screws
Insert hood flange between unit top panel flange and unit.
Tighten screws.
7 Insert outdoor-air inlet screens and spacer in channel cre¬
ated by lower filter retainer and filter support biacket.
8. Attach remaining shorter section section of filter sup-
Fig. 18 — Outdoor-Air Hood Details
9

START-UP
Use the following information and Start-Up Checklist on
page CL-1 to check out unit PRIOR to start-up.
Unit Preparation — Check that unit has been installed
in accordance with these installation instructions and all
applicable codes.
Compressor Mounting — Loosen compressor hold¬
down bolts until sideways movement of the washer
under each holddown bolt head can be obtained. Do not
loosen completely, as bolts are self-locking and will main¬
tain adjustment.
Internal Wiring — Check all electrical connections in
unit control boxes; tighten as required.
Refrigerant Service Ports and Valves — Each 50HJ
unit has 2 Schrader-type service ports per circuit; one on
the suction line and one on the liquid line. Be sure that the
caps on the ports are tight. The units also have 2 service
valves per circuit; one on the suction line and one on the
discharge line. Be sure all valves are open.
Crankcase Heaters — Heaters are energized as long
as there is power to unit.
IMPORTANT: Unit power must be on for 24 hours
prior to start-up. Otherwise, damage to compressor
may result.
Evaporator Fan — Fan belt and pulleys are factory in¬
stalled. Remove tape from the fan pulley and adjust pulleys
on 50HJ015 units as required. See Evaporator-Fan Perfor¬
mance Adjustment section on page 12. See Table 4 for Air
Quantity Limits. See Tables 5, 6A, and 6B for Fan Perfor¬
mance data. Be sure that fans rotate in the proper direction.
See Table 7 for Static Pressure Drops for accessories and
options. To alter fan performance, see Evaporator-Fan Per¬
formance Adjustment sections, pages 12 and 13.
Table 4 — Air Quantity Limits
UNIT 50HJ MINIMUM CFM
MAXIMUM CFM
015 3750 6,250
024
6000 10,000
Condenser Fans and Motors — Fans and motors
are factory set. Refer to Service, Condenser-Fan Adjust¬
ment section as required.
Return-Air Filters — Check that correct filters are
installed in filter tracks. See Table 1. Do not operate unit
without return-air filters.
Outdoor-Air Inlet Screens — Outdoor-air inlet screens
must be in place before operating unit.
Accessory Field-Installed Economizer Adjust¬
ment — Remove filter access panel. Check that outdoor-
air damper is closed and return-air damper is open.
Economizer operation and adjustment is described in
Start-Up, Base Unit Operation; and Service, Economizer
Adjustment sections, respectively.
Base Unit Operation
COOLING, UNITS WITHOUT ECONOMIZER - When
thermostat calls for cooling, terminals G and Y1 are ener¬
gized. The indoor (evaporator) fan contactor (IFC) and com¬
pressor contactor no. 1 (Cl) are energized and evaporator-
fan motor, compressor no. 1 (024) or unloaded compressor
(015), and condenser fans start. The condenser-fan motors
run continuously while unit is cooling. If the thermostat calls
for a second stage of cooling by energizing Y2, compressor
contactor no. 2 (C2) is energized and compressor no. 2 starts
(024), or compressor no. 1 runs fully loaded (015).
A freeze protection thermostat (FPT) is located on the
evaporator coil. It detects frost buildup and turns off the
compressors, allowing the coil to clear. Once frost has melted,
the compressors can be reenergized by resetting the
thermostat.
HEATING, UNITS WITHOUT ECONOMIZER (If Acces¬
sory or Optional Heater is Installed) — Upon a call for
heating through terminal Wl, IFC and heater contactor
no. 1 (HC1) are energized. On units equipped for 2 stages
of heat, when additional heat is needed, HC2 is energized
through W2.
COOLING, UNITS WITH ECONOMIZER - Upon a call
for cooling, when outdoor ambient temperature is above the
outdoor-air temperature control setting, the evaporator and
condenser fans and compressor energize. The economizer
damper moves to VENT position.
Upon a first-stage call for cooling, when outdoor ambi¬
ent temperature is below the temperature control setting,
the evaporator fan starts and economizer damper modulates
to maintain mixed-air temperature. The compressor(s) re¬
mains off.
Upon a second-stage call for cooling, compressor no 1
(024) or unloaded compressor (015) is energized and me¬
chanical cooling is integrated with economizer cooling Com¬
pressor no. 2 (024 only) is locked out. If the outdoor-air
temperature is below 50 F, a cooling lockout switch
prevents the compressor(s) from running.
When supply-air temperature drops below a fixed set point,
the economizer damper modulates to maintain the temper¬
ature at the fixed set point.
HEATING, UNITS WITH ECONOMIZER (If Accessory
or Optional Heater is Installed) — The outdoor air damper
stays at VENT position while the evaporator fan is operat¬
ing Upon a call for heating through terminal Wl, the in¬
door (evaporator) fan contactor (IFC) and heater contactor
no. 1 (HC1) are energized. On units equipped for 2 stages
of heat, when additional heat is needed, HC2 is energized
through W2.
10

Table 5 — Fan Performance Data, 50HJ015 Units
EXTERNAL STATIC PRESSURE (in. wg)
AIRFLOW
(Cfm)
0.2 0.4 0.6
0.8 1.2
1.4
1.6
L8
[M
P7ETOI
E5E1
EfflS
B3Sa
LVeuh LY/rfln
IiWiiI
GHa
pm
LiJtljjJ
mnin NFTiTl
klTiil
Watts
732
684 848
835
977
1041
1119
1124
1270
1194
1430
1247 1599
1274 1767
Hi
—
|
—
764 799 876 968
1110
1065 1261
1146 1412
1221 1572 1284 1750
1331
1927
1357
2105
—
4250
797
933
904
1101
1261 1089
1412 1170
1581
1244 1741
1312
1909
1369 2096
1413 2282 1440 2469
4500 831
1075
934
1252
1028
1430
1113 1581
1193 1750
1267
1918
1335
2096
1398
2282 1451 2478 1493 2673
4750
865 1226 965 1421 1056
1607
1139
1767
1217
1945
1290
2123 1358
2300 1422
2487
1480 2682 1531
2877
5000
900
1403
996 1599
1084 1803 1166 1980
1241 2149 1314 2336 1381 2522
1444
2709
1504
2904
—
—
5250
935
1590
1028 1794 1112
2007 1193 2202
1266 2371 1338
2567
1405 2762
1468
2948
—
—
5500 971
1794 1060
2007
1142
2229
1221
2433
1294
2629
1362 2806
1429
3011
— — —
5750
1007
2016
1093
2238
1173
2469
1249
2682 1321 2895
— — — — — — —
6000
1044
2256
1126
2487
1205
2718 1277 2948
— —
—
—
_
— — — — — —
6250 1080
2513
1159
2753
1236
2993
—
— — — — — — —
— —
-
-
LEGEND
Watts — Input Watts to Motor
NOTES:
1. F actory shipped fan speed is 1092 rpm. The range of the stand¬
ard evaporator-fan motor is 978 to 1285 rpm. Other rpms may
require a field-supplied drive.
2 S tatic pressure losses (i.e., economizer, electric heater) must be
added to external static pressure before entering Fan Perfor¬
mance table.
3. To convert watts to bhp, use the following equation:
Bh _Watts x motor efficiency
P 746
Motor efficiency: Horsepower — Maximum Continuous Watts:
0 84 3 hp - 3065
4 Interpolation is permissible Do not extrapolate.
5. Fan performance is based on wet coils, clean filters, and casing
losses.
6. Extensive motor and drive testing on these units ensures that
the full range of the motor can be utilized with confidence. Using
your fan motors up to the watts rating shown will not result in nui¬
sance tripping or premature motor failure Unit warranty will not
be affected.
Table 6A — Fan Performance Data — 50HJ024, 208/230-V and 575-V Units
EXTERNAL STATIC PRESSURE (in. wg)
AIRFLOW
rrfmt
0.2 0.4
0.6 0.8
. 1.0
1.2
1.3 1.4 1.6 1.8
Rpm Watts
Rpm Watts
Rpm Watts
Rpm
Watts Rpm Watts
Rpm
Watts Rpm Watts
Rpm
Watts
Rpm Watts Rpm
Watts
6,000
702
1428
796
1723 884 2025
965
2339
1041
2669 1115 3018 1150
3201 1186 3385 1255
3771 1322 4175
6,500
747
1757
835
2073 919
2394 997
2725
1070
3069 1140 3429
1174 3617 1208 3805
1274
4198 1338 4609
7,000
792 2138
877 2476
957
2816 1031 3165
1102 3525 1169 3898
1201
4091
1233 4285 1296
4687
1358
5106
7,500
838 2571 918
2929 996 3290
1067
3658
1135 4035 1199
4422
1230
4622 1262 4822
1322
5235
1381 5662
8,000
885 3060
962 3440 1036 3822
1105
4209
1170 4604
1232 5008
1262 5180 1292 5422 1350
5847 1407 6286
8,500
932 3610 1005
4011
1077 4414
1143 4821 1206
5234
1266
5655
1295
5870
1324
6085 1380 6524 1435
6975
9,000
980 4223 1050
4647
1119
5071 1183
5498
1244
5930
1302
6369 1330
6592 1359 6816 1413 7270
1466 7735
9,500
1028 4904 1096
5350 1162 5796
1224
6243
1283
6695
1340
7152 1367 7384 1394 7616
__
— — —
10,000
1077
5655
1141
6123 1205 6591
1266
7059
1323 7531
— —
-
— — — —
—
— —
LEGEND
Watts — Input Watts to Motor
NOTES'
1. Factory shipped fan speed is 1287 rpm Other rpms may require
a field-supplied drive.
2. Static pressure losses (i e., economizer, electric heater) must be
added to external static pressure before entering Fan Perfor¬
mance table
3. To convert watts to bhp, use the following equation:
D l „ Watts x motor efficiency
-7ACZ.
Motor efficiency: Horsepower — Maximum Continuous Watts:
0.87 71/2 hp — 7915
4 Interpolation is permissible Do not extrapolate.
5. Fan performance is based on wet coils, clean filters, and casing
losses.
6. Extensive motor and drive testing on these units ensures that
the full range of the motor can be utilized with confidence. Using
your fan motors up to the watts rating shown will not result in nui¬
sance tripping or premature motor failure. Unit warranty will not
be affected.
Table 6B — Fan Performance Data — 50HJ024, 460-V Units
EXTERNAL STATIC PRESSURE (in. wg)
AIRFLOW
(Cfm)
0.2
0.4 0.6
0.8
1.0
1.2 1.3
1.4
1.6
1.8
Rpm
Watts Rpm Watts Rpm Watts Rpm Watts
Rpm Watts Rpm Watts
Rpm Watts Rpm
Watts
Rpm
Watts
Rpm
Watts
6,000
702
1428
796 1723
884 2025 965 2339
1041
2669
1115 3018 1150 3201 1186
3385
1255
3771 1322 4175
6,500
747 1757
835
2073
919 2394
997 2725
1070
3069 1140 3429
1174
3617 1208
3805
1274 4198
1338 4609
7,000 792
2138
877
2476
957 2816
1031
3165
1102 3525 1169 3898 1201
4091
1233
4285
1296
4687
1358 5106
7,500 838
2571
918
2929
996 3290
1067
3658 1135
4035 1199 4422 1230 4622
1262 4822 1322
5235 1381
5662
8,000 885
3060
962 3440
1036 3822 1105 4209 1170
4604 1232 5008
1262
5180
1292 5422 1350
5847 1407
6286
8,500
932
3610 1005
4011
1077 4414 1143 4821 1206
5234
1266
5655
1295
5870
1324
6085 1380
6524
1435 6975
9,000 980
4223 1050
4647 1119
5071
1183 5498
1244 5930 1302 6369 1330 6592 1359
6816 1413
7270
1466
7735
9,500 1028
4904
1096 5350
1162 5796
1224
6243 1283
6695
1340
7152
1367 7384
1394 7616
1447 8088
— —
10,000
1077 5655
1141
6123
1205 6591 1266 7059 1323 7531 1378
8007
1404
8248 1431
8489
—
—
—
—
LEGEND
Watts — Input Watts to Motor
NOTES:
1 Factory shipped fan speed is 1287 rpm. Other rpms may require
a field-supplied drive.
2. Static pressure losses (i.e , economizer, electric heater) must be
added to external static pressure before entering Fan Perfor¬
mance table
3 T o convert watts to bhp, use the following equation:
R . _Watts x motor efficiency
^ 7/1C
Motor efficiency: Horsepower — Maximum Continuous Watts
0 87 7V 2 hp - 8640
4 Interpolation is permissible. Do not extrapolate.
5 Fan performance is based on wet coils, clean filters, and casing
losses.
6. Extensive motor and drive testing on these units ensures that
the full range of the motor can be utilized with confidence. Using
your fan motors up to the watts rating shown will not result in nui¬
sance tripping or premature motor failure. Unit warranty will not
be affected.
11

Table 7 - Accessory/FlOP Static Pressure Drop* (in. wg)
UNIT
50HJ
UNIT
VOLTAGE
208/230-3-60
015
460-3-60
575-3-60
208/230-3-60
024
460-3-60
575-3-60
CFM
4,000
5,000
6,000
7,200
4,000
5,000
6,000
7,200
4,000
5,000
6,000
7,200
0 05
0.07
0 09
ELECTRIC HEATERS
(kW)
(14-34) 0 06 (42) 0 07 (56)
14-34 0.08 42 0.10(56
(14-34) 0 12 (42) 0.15 (56)
El
05 (15,32) 0.06
(55)
0
07 15,32 0 08
(55)
0 09 (15,32)
012 55)
0.06 (37)
0 08 37)
0 12 37
0 15 37)
ECONOMIZER
0^3
0 05
0.07
0 09
0 03
0 05
0.07
0 09
0 03
0.05
0 07
0 09
6,000
0 09 (26/34) 0 12 (42/56) 0 15 56/75
0 07
7,200
0 11 26/34 0 16 42/56 0 20 56/75
0 09
9,000
0 15 26/34 0 19 42/56 0 24 56/75
0.11
10,000
0.17 26/34 0.21 (42/56) 0.26 (56/75)
0 12
6,000
7,200
9,000
10,000
0.09 (32) 0.12 (55) 0.15 (80)
0 11 32 0.15 (55 0 20 80
0 15 (32 0 19 55 0 24 (80
0.17(32) 0 21 (55) 0.26 (80)
6,000
_
7,200
—
9,000
—
10,000
—
0 07
0 09
0.11
0.12
0 07
0 09
0.11
0 12
FIOP — Factory-Installed Option NOTE: Heaters are rated at 208/240 v, 480 v, and 575 v
"The static pressure must be added to external static pressure The sum and
the evaporator entering air cfm should then be used in conjunction with the
Fan Performance table to determine blower rpm and watts
SERVICE
A WARNING
Before performing service or maintenance operations
on unit, turn off main power switch to unit. Turn off
accessory heater power switch if applicable. Electrical
shock could cause personal injury.
Cleaning — Inspect unit interior at beginning of each
heating and cooling season and as operating conditions re¬
quire. Remove unit top panel and/or side panels for access
to unit interior.
EVAPORATOR COIL — Clean as required with a com¬
mercial coil cleaner.
CONDENSER COIL — Clean condenser coil annually and
as required by location and outdoor-air conditions. Inspect
coil monthly — clean as required.
CONDENSATE DRAIN — Check and clean each year at
start of cooling season.
FILTERS — Clean or replace at start of each heating and
cooling season, or more often if operating conditions re¬
quire. Refer to Table 1 for type and size.
OUTDOOR-AIR INLET SCREENS — Clean screens with
steam or hot water and a mild detergent. Do not use dis¬
posable filters in place of screens.
Lubrication
COMPRESSORS — Each compressor is charged with cor¬
rect amount of oil at the factory. Observe the oil level in
the sight glass at start-up. If unit oil level is below sight
glass, add oil until level is approximately l A sight glass.
FAN SHAFT BEARINGS — The bearings are of the pil¬
low block type and have grease fittings. The bearing oppo¬
site the motor end has an extended tube line so it can be
lubricated from the motor side. Lubricate the bearings twice
annually.
Typical lubricants are given below:
MANUFACTURER
LUBRICANT
Texaco
Reqal AFB-2*
Mobil
Mobilplex EP No. 1
Sunoco
Prestige 42
Texaco Multifak 2
‘Preferred lubricant because it contains rust and oxidation inhibitors
CONDENSER AND EVAPORATOR-FAN MOTOR BEAR¬
INGS — The condenser and evaporator-fan motors have
permanently-sealed bearings, so no field lubrication is
necessary.
Evaporator Fan, 50HJ015 Units
PERFORMANCE ADJUSTMENT — Fan motor pulleys on
the 50HJ015 units are factory set for speed shown in
Table I.
To change fan speeds:
1. Shut off unit power supply.
2. Loosen belt by loosening fan motor mounting plate nuts.
3. Loosen movable-pulley flange setscrew (see Fig. 19).
4. Screw movable flange toward fixed flange to increase
speed and away from fixed flange to deccrease speed.
Increasing fan speed increases load on motor. Do not
exceed maximum speed specified in Table 1.
5. Set movable flange at nearest key way of pulley hub and
tighten setscrew. (See Table 1 for speed change for each
full turn of pulley flange.)
To align fan and motor pulleys:
1. Loosen fan pulley setscrews.
2. Slide fan pulley along fan shaft.
3. Make angular alignment by loosening motor from mount¬
ing plate.
SERVICE AND REPLACEMENT (see Fig. 20)
NOTE: To remove belts only, follow Steps 1-7.
1. Remove filter and supply-air section panels.
2. Remove unit to cover.
3. Remove coil guard.
4. Loosen screws A and B on both sides of motor mount
assembly.
5. Loosen screw C.
6. Rotate motor mount assembly (with motor attached) as
far as possible away from evaporator coil.
7. Remove belt.
12

8 Rotate motor mount assembly back past original posi¬
tion toward evaporator coil.
9. R emove motor mounting nuts D and E (both sides).
10. L ift motor up through top of unit.
11 Reverse above procedure to reinstall motor.
12. Check and adjust belt tension as necessary.
Fig. 19 - Evaporator-Fan Pulley Alignment
and Adjustment
Fig. 20 — 50HJ015 Evaporator-Fan Motor Section
Evaporator Fan, 50HJ024 Units
PERFORMANCE ADJUSTMENT - The 50HJ024 unit has
fixed pulleys. Fan speed can be adjusted (if necessary) only
by changing the pulley(s) and belt. See Table 8 for alter¬
nate drive selection.
To align fan and motor pulleys (see Fig. 19):
1. Loosen fan pulley setscrews.
2. Slide fan pulley along fan shaft.
3. Make angular alignment by loosening motor from mount¬
ing plate.
SERVICE AND REPLACEMENT (See Fig. 21) - The
50HJ024 unit uses a fan motor mounting system that fea¬
tures a slide-out motor mounting plate. To replace or serv¬
ice the motor, slide out the bracket.
1. Remove the evaporator-fan access panel and the heat¬
ing control access panel.
2. Remove the center post (located between the evapora¬
tor fan and heating control access panels) and all screws
securing it
3. Loosen nuts on the two carriage bolts in the motor mount¬
ing base.
4. Using jacking bolt under motor base, raise motor to
top of slide and remove belt. Secure motor in this po¬
sition by tightening the nuts on the carriage bolts.
5. Remove the belt drive.
6. Remove jacking bolt and tapped jacking bolt plate.
7. Remove the 2 screws that secure the motor mounting
plate to the motor support channel.
8. Remove the 3 screws from the end of the motor sup¬
port channel that interfere with the motor slide path.
9 Slide out the motor and motor mounting plate,
10. Disconnect wiring connections and remove the 4 mount¬
ing bolts.
11. Remove the motor.
12. To install the new motor, reverse Steps 1-11.
NOTE: A 3V2-in. bolt and threaded plate are included in the install¬
er’s packet. They can be added to the motor support channel below
the motor mounting plate to aid in raising the motor.
Fig. 21 — 50HJ024 Evaporator-Fan Motor Section
13

Table 8 — Alternate Drive Components Table, 50HJ024
UNIT
50HJ
MOTOR
HP
DRIVE
SOURCE
i
! FAN
RPM
MOTOR
SHEAVE DATUM
DIMENSION*
(in.)
MOTOR
SHEAVE
PART NO.t
BLOWER
SHEAVE DATUM
DIMENSION*
(in.)
BLOWER
SHEAVE
PART NO.f
BELT
PART NO.f
7V2
Field
1181
5.6
BK62 8.4
BK90
BX50
024
Th
Field
1244
5.9
BK65 8.4
BK90
BX51
V/2
Factory 1287
6 1
BK67 84
BK90 BX51
1V2 Field
1379
6.6
BK72 8.4
BK90
BX52
LEGEND
MPTA — Mechanical Power Transmission Association
RMA — Rubber Manufacturers’ Association
‘Datum dimension is equal to the old pitch diameter per RMA/MPTA
Standard IP20-1977. to convert to new pitch diameter per RMA/
MPTA Standard IP20-1988, add 0.3 in. to the sheave datum
dimension.
tPart numbers for motor sheave, blower sheave, and belt are Brown¬
ing Catalog part numbers. The motor sheaves have Browning fixed
bore sheaves supplied with factory drive package.
Belt Tension Adjustment — To adjust belt tension:
1. Loosen fan motor bolts.
2. a. 015 units:
Move motor mounting plate up or down for proper
belt tension ( l h in. deflection with one finger),
b. 024 units:
Turn motor jacking bolt to move motor mounting plate
up or down for proper belt tension (Vs in. deflection
at midspan with one finger [9 lb force]).
3. Tighten nuts.
4. Adjust bolts and nut on mounting plate to secure motor
in fixed position.
Condenser-Fan Adjustment (Fig. 22)
1. Shut off unit power supply.
2. Remove fan top-grille assembly and loosen fan hub screws.
3. Adjust fan height on unit, using a straightedge placed
across the fan orifice.
4. Tighten setscrews and replace rubber hubcap to prevent
hub from rusting to motor shaft.
5. Fill hub recess with permagum if rubber hubcap is
missing.
Economizer Adjustment — Refer to Tables 9 and
10 for economizer checkout procedures. Make certain the
outdoor-air damper is fully closed and the return-air damper
is fully open before completing the following steps.
1. Turn on power to the unit.
2. Turn the thermostat fan switch to the ON position. The
damper will go to the vent position.
3. Adjust the vent position with the minimum position ad¬
justment on the economizer control module. See
Fig. 14.
Fig. 22 - Condenser-Fan Adjustment
4. Set the system selector switch to COOL position and
set the cooling temperature selector to its lowest
setting.
NOTE: The cooling mode may also be simulated by remov¬
ing the thermostat wires from terminals Y1 and Y2 and in¬
stalling a jumper between terminals R and Y1, Refer to unit
label diagram for terminal locations.
5. Set the outdoor-air thermostat (OAT) located in the econo¬
mizer section of the unit to 75 F.
6. If the outdoor temperature is below 75 F, the econo¬
mizer will control the mixed air with the mixed-air sen¬
sor. If the outdoor air is above 75 F, place a jumper
around the contacts of the OAT
7. Jumper terminal T to terminal T1 on the module (see
Fig. 14). The economizer will go to the full open
position. The outdoor-air damper will go to the full open
position, and the return-air damper will go to the full
closed position.
8. Adjust mechanical linkage, if necessary, for correct po¬
sitioning. It may be necessary to remove the filters to
adjust the linkage.
9. Remove the jumper from around the contacts of the
OAT if installed in Step 6. Remove the jumper from
terminals T and T1 installed in Step 7.
10. I f the cooling mode was simulated to operate the unit
in Step 4, remove the jumper and reconnect the ther¬
mostat wires to terminals Y1 and Y2.
Power Failure — Dampers have a spring return In event
of power failure, dampers will return to fully closed posi¬
tion until power is restored. Do not manually operate damper
motor.
Refrigerant Charge — Amount of refrigerant charge
is listed on unit nameplate and in Table 1. Refer to Carrier
GTAC II; Module 5; Charging, Recovery, Recycling, and
Reclamation section for charging methods and procedures.
Unit panels must be in place when unit is operating dur¬
ing charging procedure.
NO CHARGE — Use standard evacuating techniques.
After evacuating system, weigh in the specified amount of
refrigerant (refer to Table 1).
LOW CHARGE COOLING - Using appropriate cooling
charging chart (see Fig. 23 and 24), add refrigerant until
conditions of the chart are met. Note that charging charts
are different from those normally used. Charts are based on
charging units to correct superheat for various operating con¬
ditions. An accurate pressure gage and temperature sensing
device are required. Connect temperature sensing device to
service port on suction line and insulate it so that outdoor
ambient temperature does not affect reading. Indoor-air cfm
must be within normal operating range of unit.
14

Table 9 - Economizer Checkout Procedures
100
test procedure
RESULTS
A Disconnect power at
TR and TR1
Disconnect jumper
between P and
PI. See Fig 14
B. Jumper TR to 1
C. Jumper T1 to T.
D. Disconnect outdoor-air
thermostat connections
from S Q and +
Factory-installed
800 ohm resistor
should remain connected
to S R and +.
E Reconnect power to
terminals TR and TR1
1. LED (light-emitting diode)
should be off.
2. Motor is in closed position
TEST PROCEDURE
RESULTS
A Disconnect
factory-installed
resistor from
terminals S R and +
1 LED (light-emitting diode)
should be on
2. Motor drives toward open
Table 10 — High and Low Outdoor-Air
Temperature Simulation
TEST PROCEDURE
RESULTS
A Reconnect factory-
installed 800 ohm resistor
between terminals
S R and +
B. Connect 1200 ohm
checkout resistor
between terminals
S Q and +.
C. Turn set point potentiom¬
eter to position A
Low outdoor-air temperature
test results:
1 LED (light-emitting diode)
should be on
2 Motor drives toward open
D. Turn set point potentiom¬
eter to position D
E Disconnect 1200 ohm
checkout resistor
High outdoor-air temperature
test results
1 LED should be off
2 Motor drives toward closed.
TO USE COOLING CHARGING CHART - Take out¬
door ambient temperature and read the suction pressure gage.
Refer to appropriate chart to determine correct suction tem¬
perature. If suction temperature is high, add refrigerant. If
suction temperature is low, carefully reclaim some of the
charge. Recheck suction pressure as charge is adjusted
Filter Drier — Replace whenever refrigerant system is
exposed to atmosphere.
40 50 60
SUCTION LINE TEMP (F)
Fig. 23 — Cooling Charging Chart — 50HJ015
Fig. 24 - Cooling Charging Chart - 50HJ024
i
15

Protective Devices
COMPRESSOR PROTECTION
Overcurrent — Each compressor has one manual reset, cal¬
ibrated trip, magnetic circuit breaker. Do not bypass con¬
nections or increase the size of the circuit breaker to correct
trouble. Determine the cause and correct it before resetting
the breaker.
Overtemperature — Each compressor has an internal pro¬
tector to protect it against excessively high discharge gas
temperatures.
Crankcase Heaters — Each compressor has 125-watt crank¬
case heaters to prevent absorption of liquid refrigerant by
oil in the crankcase when the compressor is idle. Since power
for the crankcase heaters is drawn from the unit incoming
power, main unit power must be on for the heaters to be
energized.
IMPORTANT: After a prolonged shutdown or serv¬
ice job, energize the crankcase heaters for 24 hours
before starting the compressors
Compressor Lockout — If any of the safeties (high- or low-
pressure, freeze protection thermostat, compressor internal
thermostat) trip, or if there is loss of power to the compres¬
sors, the CLO (compressor lockout) will lock the compres¬
sors off. To reset, manually move the thermostat
setting.
EVAPORATOR-FAN MOTOR PROTECTION - A man¬
ual reset, calibrated trip, magnetic circuit breaker protects
against overcurrent. Do not bypass connections or increase
the size of the breaker to correct trouble. Determine the
cause and correct it before resetting the breaker.
CONDENSER-FAN MOTOR PROTECTION - Each
condenser-fan motor is internally protected against over¬
temperature.
HIGH- AND LOW-PRESSURE SWITCHES - If either
switch trips, or if the compressor overtemperature switch
activates, that refrigerant circuit will be automatically locked
out by the CLO To reset, manually move the thermostat
setting
FREEZE PROTECTION THERMOSTAT (FPT) - An
FPT is located on the evaporator coil. It detects frost
buildup and turns off the compressor, allowing the coil to
clear. Once the frost has melted, the compressor can be
reenergized by resetting the CLO from the thermostat.
Relief Devices — All units have relief devices to pro¬
tect against damage from excessive pressures (i.e., fire).
These devices protect the high and low side.
Control Circuit, 24-V — This control circuit is pro¬
tected against overcurrent by a 3.2-amp circuit breaker. Breaker
can be reset. If it trips, determine cause of trouble before
resetting.
Replacement Parts — A complete list of replace¬
ment parts may be obtained from any Carrier distributor
upon request.
16

PACKAGED SERVICE TRAINING
Our packaged service training programs provide an excellent way to increase your knowledge of the
equipment discussed in this manual. Product programs cover:
• Unit Familiarization • Maintenance
• Installation Overview • Operating Sequence
A large selection of product, theory, and skills programs is available. All programs include a video
cassette and/or slides and a companion booklet. Use these for self teaching or to conduct full training
sessions.
For a free Service Training Material Catalog (STM), call 1-800-962-9212. Ordering instructions are
included
Copyright 1993 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
BookII PC 111 Catalog No 565-125 Printed in U S A Form 50HJ-6SI Pg 18 12-93 Replaces: New
Tab 11b

START-UP CHECKLIST
{Remove and Store with Job File)
MODEL NO.:_ SERIAL NO.: .
DATE:_ TECHNICIAN.
PRE-START-UP:
□ VERIFY THAT ALL PACKING MATERIALS HAVE BEEN REMOVED FROM UNIT
□ REMOVE ALL SHIPPING HOLDDOWN BOLTS AND BRACKETS PER INSTRUCTIONS
□ VERIFY INSTALLATION OF ECONOMIZER HOOD
□ VERIFY THAT CONDENSATE CONNECTION IS INSTALLED PER INSTRUCTIONS
□ VERIFY THAT ALL ELECTRICAL CONNECTIONS AND TERMINALS ARE TIGHT
□ CHECK THAT INDOOR-AIR FILTER IS CLEAN AND IN PLACE
□ VERIFY THAT UNIT IS LEVEL
□ CHECK FAN WHEEL AND PROPELLER FOR LOCATION IN HOUSING/ORIFICE, AND VERIFY SET
SCREW IS TIGHT
□ VERIFY THAT FAN SHEAVES ARE ALIGNED AND BELTS ARE PROPERLY TENSIONED
START-UP
ELECTRICAL
SUPPLY VOLTAGE
L1-L2
L2-L3
L3-L1
COMPRESSOR AMPS
- COMPRESSOR NO. 1
LI L2
L3
- COMPRESSOR NO 2
LI L2
L3
SUPPLY FAN AMPS _ EXHAUST FAN AMPS _
ELECTRIC HEAT AMPS LI _ L2 _ L3 _
TEMPERATURES
OUTDOOR-AIR TEMPERATURE _F DB (Dry-Bulb)
RETURN-AIR TEMPERATURE _F DB _F WB (Wet-Bulb)
COOLING SUPPLY AIR F
ELECTRIC HEAT SUPPLY AIR _F
PRESSURES
REFRIGERANT SUCTION CIRCUIT NO. 1 _PSIG CIRCUIT NO. 2 _PSIG
REFRIGERANT DISCHARGE CIRCUIT NO. 1 _PSIG CIRCUIT NO. 2 _PSIG
□ VERIFY REFRIGERANT CHARGE USING CHARGING CHARTS ON PAGE 15.
GENERAL
□ ECONOMIZER MINIMUM VENT AND CHANGEOVER SETTINGS TO JOB REQUIREMENTS
Copyright 1993 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1
Tab 1b
PC 111
Catalog No 565-125
Printed in U S A Form 50HJ-6SI CL-1
12-93
Replaces: New