Carrier 38HD018 Dimensions and installation guide

38HD
’ Split System Condensing Units
HEATING & COOLING
Installation, Start-Up and Service
Instructions
SAFETY CONSIDERATIONS
Installing and servicing air conditioning equipment
can be hazardous due to system pressure and electrical
components Only trained and qualified service personnel
should install or service air conditioning equipment.
Untrained personnel can perform basic maintenance,
such as cleaning and replacing filters. All other opera¬
tions should be performed by trained service personnel.
When working on air conditioning equipment, observe
precautions in literature and on tags and labels attached
to unit
Follow all safety codes. Wear safety glasses and work
gloves. Use quenching cloth for brazing operations.
Have fire extinguisher available. Read these instruc¬
tions thoroughly. Consult local building codes and
National Electrical Code (NEC) for special installation
requirements
A WARNING
Before installing or servicing system, always turn off
main power to system. There may be more than one
disconnect switch. Turn off accessory heater power if
applicable Electrical shock can cause personal injury.
Fig. 1 - Model 38HD
INSTALLATION
Step 1 — Complete Pre-Installation Checks.
UNPACK UNIT (See Fig I.) — Move unit to final
location Remove carton from unit being careful not to s
damage service valves and grilles. •
INSPECT SHIPMENT — File claim with shipping
company if shipment is damaged or incomplete.
CONSIDER SYSTEM REQUIREMENTS — Consult
local building codes and National Electrical Code (NEC)
for special installation requirements.
Allow sufficient space for airflow clearance, wiring,
refrigerant piping, and servicing unit. See Fig. 2 and 3.
Locate unit so that condenser airflow is unrestricted
on both sides. Refer to Fig 2 and 3.
Unit may be mounted on a level pad directly on base
legs or mounted on raised pads at support points See
Fig. 2 and 3 for center of gravity
CHECK ACCURATER® — The correct AccuRater
(bypass type) refrigerant control is required for cooling
system capacity optimization. An AccuRater with field-
replaceable piston (see Fig. 4) is supplied on evaporator.
Use Optimization Chart, Table 1, to find AccuRater
piston size required for condenser/evaporator system
being installed. Note that one of 2 types of AccuRaters
can be found on the indoor unit. Determine from Fig. 4
and Table 1 which type is in the indoor unit. Do not inter¬
change components between AccuRater types. Matching
of condensing unit with evaporator may require field
replacement of piston. Refer to Table 1. Replace piston,//
required, before connecting refrigerant lines. Piston
replacement instructions are included in evaporator
installation book. After system installation is complete,
see Refrigerant Charging to check and/or adjust refrig¬
erant charge
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC111
Catalog No 533-850 PrintedinUSA Form38HD-1SI
Pgi
6-89
Replaces: New
Tab
3a 2a
For replacement items use Carrier Specified Parts.

**'' CLEARANCES FOR SERVICE AND AIRFLOW.
ALLOW 6 IN. ABOVE UNIT.
6 IN.
k 6
H
_L
HIGH VOLTAGE
1-1/8' DIA.
HORIZONTAL AIR
DISCHARGE
FIS® [MT ¥ 0 E W
[^D@[Hnr
I EH
WOiW
UNIT
WEIGHT
A
B
C
38HD018
(67 1 kg) 148 lbs
(329)
r-r
(15 88) 5 /b"
(9 53) %"
38HD024
(72 6 kg) 160 lbs
(329)
V-1"
(15 88) 5 / 8 "
(9 53) 3 /a"
38HD030
(77 6 kg) 171 lbs
(329)
r-r
(15.88) %"
(9.53) %"
NOTES
1 Dimensions in [ ] are in millimeters
2 Air Direction «=>
3. Center of Gravity ^
4 Footprint 018-030, 3 7 sq ft ( 34 m 2 )
Fig. 2 — 38HD Dimensional Drawing, 018-030

-[1132] -
3'-8 9/IB
HORIZONTAL
AIR
DISCHARGE
I
FBOMT WDIM
UNIT
WEIGHT
A B C
38HD036 (108 9 kg) 240 lbs
(352)
1 '-1 %"
(19 05) 3 /4"
(9 53) 3 / 8 "
38HD048
(110 7 kg) 244 lbs
(347)
1 '-1 %"
(19 05) %"
(9.53) %"
38HD060
(110 7 kg) 244 lbs
(368)
1'-2M>"
(22 22) %"
(9 53) %"
Fig. 3 — 38HD
NOTES
1 Dimensions in [ ] are in millimeters
2 Air Direction
3 Center of Gravity
4 Footprint 036-060, 5 3 sq ft (49 m 2 )
Drawing, 036-060

RETAINER
Table 1 — AccuRater Optimization Chart
TYPE A
(Arrow on AccuRater body points in metering direction.)
(Arrow on AccuRater body points in free flow direction.)
Fig. 4 — AccuRater® (Bypass Type) Components
Step 2 — Rig and Mount Unit
MOUNTING ON GROUND — Mount on a solid, level,
concrete pad Position unit so water or ice from roof
cannot drop directly onto unit. Stacking Kit 38 H D900031
and T)41 are available where such application is required.
See instructions provided with accessory kit. If conditions
or local codes require unit be fastened to pad, tiedown
bolts should be used and fastened through slots provided
in unit mounting feet.
MOUNTING ON ROOF — Mount on a level platform
or frame.
RIGGING
Be sure
| rigging.
unit panels are securely in place prior to
Keep unit upright. Lift unit using sling. Use cardboard
or padding under sling, and spreader bars to prevent sling
damage to unit. See Fig. 5. See Fig. 2 and 3 for center of
gravity reference. Install unit so that coil does not face
into prevailing winds. If this cannot be done, and constant
winds above 25 mph are expected, use Accessory Wind
Baffle, Part Number 38QR900041 or -051. See instruc¬
tions provided with accessory kit
Step 3 — Complete Refrigerant Piping Con¬
nections — Condensing units may be connected to
evaporator sections using field-supplied tubing of refrig¬
erant grade, correct size and condition. See Table 2.
Do not use less than 10 ft of interconnecting tubing and
do not bury more than 3 ft of line set underground. If any
section is buried, there must be a 6-in. vertical rise to the
valve connections on the outdoor unit
OUTDOOR
UNIT
INDOOR
UNIT
INDOOR
PISTON
PISTON
TYPE
REQUIRED
SYSTEM
CHARGE (lb)
38HD018
28RD024
40HD024
_
A
B
-
38HD024
i
28RD030
40HD024
61
A
B
55
38HD030
28RD043
40HD036
70
A
B
57
38HD036
28RD043
40HD036
73
A
B
11.5
38HD048
28RD049
40HD048
86
A
B
97
38HD060
28RD061
40HD060
88 A
B
11 2
If more than the recommended length is buried, refrig¬
erant may migrate to cooler buried section during
extended periods of unit shutdown. This causes refrig¬
erant slugging and possibly compressor damage at
start-up.
When more than 50 ft of interconnecting tubing and
more than 30 ft vertical lift is used, consider the amount of
liquid lift, and compressor oil return See Part 3 of Carrier
System Design Manual for design details, or contact your
local Distributor
If either refrigerant tubing or indoor coil is exposed to
atmospheric conditions for longer than 5 minutes, it must
be evacuated to 1000 microns to eliminate contamination
and moisture in the system.
Run refrigerant tubes as directly as possible, avoiding
unnecessary turns and bends. Suspend refrigerant tubes
so they do not damage insulation on vapor tube and do
not transmit vibration to structure Also, when passing
refrigerant tubes through wall, seal opening, so vibration
is not transmitted to structure. Leave some slack in refrig¬
erant tubes between structure and unit to absorb vibra¬
tion Refer to evaporator installation instructions for
additional information.
USE FILTER DRIER AND MOISTURE INDI¬
CATOR — The filter drier is factory supplied. Moisture
indicator (sight glass) is a field-supplied option and
4

Table 2 — Physical Data
UNIT 38HD 018 024
030
036
048
060
OPER WT (lb), 1 ph/3 ph
148/*
160/*
171/* 240/226
244/235
244/235
REFRIGERANT
I R-22
COMPRESSOR
Model
Oil (pts), initial/recharge
Crankcase Heater Watts
Tecumseh
AW5519
32/30
Tecumseh
AW5524
32/30
Hermetic
Carlyle 1 Carlyle 1
J30 | J36 1
46/44
40
1 Carlyle
| J48
Copeland
CRP5-0450
70/66
CONDENSER AIR FAN 1
Number — Rpm
Diameter (in.) — no. blades
Fan Pitch
Motor Hp (NEMA)
Nominal Cfm
18 — 3
25 | 27
Vs
1835 | 1720 |
Propeller, C
1 —
j 1750
>irect Drive
850
24 — 3
24
%
3900
CONDENSER COIL
Rows
Face Area (sq ft)
Fins/in.
Vh
i .
61
2
1
15
1 2 |
12.3
! 2
CONNECTIONS
Suction (in.), Sweat
Liquid (in.), Flare
% I
i % i
%
7 /s
LINE SIZES
Suction
Liquid
%
i %
% |
m
CONTROLS
Pressurestat Settings
Ui/lh Cutout
Hlgh Cut-in
426 ± 7
320 ± 20
i «... Cutout
Low Cut-in
7 ± 5
22 ± 5
FUSIBLE PLUG
210 F
*Not applicable
should be installed just after liquid line shutoff valve. PROVIDE SAFETY RELIEF — A fusible plug is
Do not use a receiver (a receiver is not provided with unit located in unit suction line. Do not cap this plug. If local
and one should not be used). code requires additional safety devices, install as directed.
MAKE PIPING SWEAT CONNECTIONS — Remove
plastic caps from liquid and suction service valves.
Use refrigerant grade tubing. Service valves are closed
from the factory and ready for brazing. After wrapping
the service valve with a wet cloth, the tubing set can be
brazed to the service valve using either silver bearing or
non-silver bearing brazing material. Consult local code
requirements. Refrigerant tubing and indoor coil are now
ready for leak testing.
NOTE: Unit is shipped with R-22 factory holding charge
indicated on nameplate.
Pass nitrogen or other inert gas through piping while
brazing to prevent formation of copper oxide.
A CAUTION
To avoid damage while brazing, service valves should
be wrapped with a heat-sinking material such as a wet
cloth.
Step 4 — Complete Electrical Connections
POWER WIRING — Unit is factory wired for voltage
shown on nameplate. Provide adequate fused disconnect
switch within sight of unit, readily accessible, but out of
reach of children. Provision for locking switch open (off)
is advisable to prevent power from being turned on while
unit is being serviced. Disconnect switch, fuses, and field
wiring must comply with National Electrical Code and
local code requirements. Use copper wire only between
disconnect switch and unit. Use minimum 60 C wire for
field power connection.
Route power wires through opening in unit side panel
and connect in unit control box as shown on unit label
diagram and Fig. 6. Unit must be grounded
5

1
ARRANGEMENT A-(COOLlNG ONLY)
J
ARRANGEMENT B-ONE TRANSFORMER
(COOLING AND ONE-STAGE HEATING)
rHr
ARRANGEMENT C-ONE TRANSFORMER
(COOLING AND TWO-STAGE HEATING)
*IFR and IFM are located in furnace on heating-cooling applica¬
tions If accessory IFR is required for cooling-only applications,
locate (IFR) in fan coil
c
— Contactor (12-va)
-— Field Wiring
HC
— Heating Control
IFM
— Indoor Fan Motor
IFR
— Indoor Fan Relay
Trans — Transformer
NOTE Refer to unit wiring label for wire colors CtoGandCtoY
connections
Fig. 6 — Typical Control Circuit Connections
CONTROL CIRCUIT WIRING — Control voltage is
24 volts (40 va minimum). See Fig. 6 and unit label
diagram for field-supplied wiring details. Route control
wires through opening in unit side panel to connection in
unit control box.
TB — Terminal Board
■ O - TB Connections
-Field Wiring
. Factory Wiring
Fig. 7 — Line Power Connections
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
14 AWG insulated wire (35 C minimum).
NOTE: Operation of unit on improper line voltage con¬
stitutes abuse and could affect Carrier warranty See
Table 3. Do not install unit in system where voltage may
fluctuate above or below permissible limits.
See Table 3 for recommended fuse sizes. When making
electrical connections, provide clearance at unit for refrig¬
erant piping connections
Use furnace oi fan coil transformer as 24-v (40-va
minimum) supply for system as shown in Fig. 7 or use
accessory transformer.
A WARNING
To avoid personal injury, be sure indoor blower has
stopped before attempting service or maintenance.
Operating voltage to compressor must be within
voltage range indicated on unit nameplate. On 3-phase
units voltages between phases must be balanced within
2% U se the following formula to determine the % voltage
imbalance.
% Voltage Imbalance
^ max voltage deviation frqm average voltage
~~ average voltage
6

Table 3 — Electrical Data (60 Hz)
OUTDOOR
i imit ooun
V/PH
OPER VOLTS*
COMPR FAN
Cl A
MCA
MAX FUSE
OR HACR TYPE
UNI I oonu
Max
Min
LRA RLA
rLM
CKT BKR AMPS
018
52 0 84 .70
120 15
024
60.0 10.6 70
140 20
030
036
208/230-1 254
187
65 0
82 0
13.5
16 5
70
1 45
180
22 0
30
35
048
127 0 25 0
1 45
33 0
50
060
135 0 30.7 1.45
40 0
60
036
67 5 10.0
1 45
140
20
048
208/230-3
254
187
98 5
15 4 1.45 21 0 35
060
105.0 19.6 1.45 26 0 45
036
33 8 50 80 70 15
048
460-3
506 414
49 3 77
80
11 0
15
060
55 0
104 .80 14.0 20
FLA — Full Load Amps
HACR — Heating, Air Conditioning, Refrigeration
LRA — Locked Rotor Amps
MCA — Minimum Circuit Amps per NEC Section 430-24
RLA — Rated Load Amps (compressor)
*Permissible limits of the voltage range at which unit will operate
satisfactorily
NOTE: Control circuit is 24v on all units and requires external
power source
Example: Supply voltage is 460-3-60.
START-UP
AB = 452 volts
BC = 464 volts
AC - 455 volts
Average Voltage =
452 + 464 + 455
3
1371
3
= 457
Determine maximum deviation from average voltage
(AB) 457 - 452 = 5 volts
(BC) 464 - 457 = 7 volts
(AC) 457 - 455 = 2 volts
Maximum deviation is 7 volts.
Determine % voltage imbalance:
% Voltage Imbalance = 100 x —= 1.53%
This amount of phase imbalance is satisfactory as it is
below the maximum allowable 2%.
Preliminary Checks
1 Check that all internal wiring connections are tight
and that all barriers, covers and panels are in place.
2. Field electrical power source must agree with unit
nameplate rating
3 All service valves must be open.
4. Crankcase heater must be tight on compressor
crankcase.
Leak Test field piping and fan coil by pressure method
described in Carrier Standard Service Techniques
Manual, Chapter 1, Section 1-6. Use R-22 at approxi¬
mately 25 psig backed up with an inert gas to a total
pressure not to exceed 245 psig.
Before starting unit, crankcase heater must be on for
24 hours to be sure all refrigerant is out of the oil . To
energize crankcase heater, proceed as follows: set space
thermostat above ambient so there will be no demand for
cooling. Close field disconnect. The crankcase heater
is now energized.
IMPORTANT: If the supply voltage phase im¬
balance is more than 2% contact your local electric
utility company immediately.
Unit failure as a result of operation on improper line
voltage or excessive phase imbalance constitutes abuse
and may cause damage to electrical components. Such
operation would invalidate any applicable Carrier
warranty.
Evacuate and Dehydrate field piping and fan coil
by either of the methods described in Carrier Standard
Service Techniques Manual, Chapter 1, Section 1-7.
A CAUTION
Service valves must be fully backseated to close
service port. There is no Schrader valve at the service
port and failure to backseat the valve could result in
loss of system charge or personal injury.
7

A CAUTION
Charge System — Release holding charge into sys¬
tem by opening (backseating) liquid and suction line
service valves. Add charge amount as required for the
total system. See Table 1. For indoor sections not in¬
cluded in Table 1, see Refrigerant Charging.
To Start Unit — Assuring that crankcase heater has
been on for 24 hours, and field disconnect is closed, set
room thermostat below ambient. Unit compressor starts
after a 5-minute delay if equipped with optional Time
Guard® 11. Operate unit for 15 minutes, then check
system refrigerant charge. See Refrigerant Charging.
SERVICE
A CAUTION
Before performing recommended maintenance, be
sure unit main power switch is turned off. Failure to
do so may result in electric shock or injury from
rotating fan blade.
Condenser Fan is held by a reinforced wire mount
which clamps the fan motor in position. See Fig. 8 for
proper mounted fan position.
OUTSIDE EDGE OF
FAN DECK
qo B.a.anQQ qqqqo
OUTSIDE EDGE
OF GRILLE
^^FAN BLADE
1
I
DIMENSION FROM
OUTSIDE TOP EDGE OF
BLADE TO OUTSIDE EDGE
OF FAN DECK SEE
CHART BELOW
UNIT SIZE
38HD018
38HD024,030
38HD036,048,060
433" (11 mm)
709" (18 mm)
16" (4 mm)
Fig. 8 — Mounted Fan Positions
High Pressure Relief Valve is located in com¬
pressor. Relief valve opens at a pressure differential of
approximately 450 ± 50 psig between suction (low side)
and discharge (high side) to allow pressure equalization.
Internal Current and Temperature Sensitive
Overload resets automatically when internal com¬
pressor motor temperature drops to a safe level (over¬
loads may require up to 45 minutes to reset) When an
internal overload is suspected of being open, check by
using an ohmmeter or continuity tester. If necessary,
refer to Carrier Standard System Techniques Manual,
Chapter 2, for complete information.
Pumpdown Procedure — The system may be
pumped down in order to make repairs on low side with¬
out losing complete refrigerant charge.
1. Attach pressure gage to suction service valve gage
port.
2. Frontseat the liquid line valve.
3. Start unit and run until suction pressure reaches
5 psig (see Caution).
4. Shut unit off and frontseat suction valve.
5. Vent remaining pressure.
38HD unit coils hold only the factory designated
amount of refrigerant. Additional refrigerant may
cause units to relieve pressure through internal
pressure relief valve (indicated by a sudden rise of
suction pressure) before suction pressure reaches
5 psig. If this occurs, shut off unit immediately,
frontseat suction valve and vent remaining pressure.
Filter Drier — Whenever the moisture-liquid indicator
shows presence of moisture, replace filter drier. Refer to
Carrier Standard Service Techniques Manual, Chapter 1,
Refrigerants, for details on servicing filter driers.
High -Pressure Switch — This switch, located on
discharge line, protects against high discharge pressures
caused by such events as overcharge, condenser fan motor
failure, system restriction, etc. It opens on pressure rise at
about 426 psi. If system pressures go above this setting
during abnormal conditions, switch opens. Do not
attempt to simulate these system abnormalities, as high
pressures pose a serious safety hazard. High-pressure
switch is also checked with an ohmmeter similar to check¬
ing low-pressure switch. If system pressure is below
426 psi, switch shows continuity. It is replaced in same
manner as low-pressure switch. Observe all safety
precautions.
Low-Pressure Switch — This switch, mounted on
the suction line, has fixed nonadjustable settings.
TO CHECK — Attach pressure gage to suction service
valve gage port. Slowly close liquid shutoff valve and
allow compressor to pump down. Do not allow com¬
pressor to pump down below 2 psig (13.8 kPa). Com¬
pressor should shut down when suction pressure drops to
cutout pressure in Table 2, and should restart when
pressure builds up to cut-in pressure shown after CLO
(Compressor Lockout) has been reset and optional Time
Guard has completed its timing cycle.
Crankcase Heater prevents refrigerant migration and
compressor oil dilution during shutdown when com¬
pressor is not operating. If crankcase heater is de¬
energized for more than 6 hours, both compressor service
valves must be closed.
Crankcase heaters come in 2 basic types: wraparound
(bellyband) type that is wrapped externally around com¬
pressor shell, and insertion type that is inserted into
compressor oil well in shell of compressor. Both types
are in this family of units.
Crankcase heater is powered by high-voltage power of
unit. It is connected across the line side of the contactor
and operates continually. Use extreme caution trouble¬
shooting this device with power on. Easiest method of
troubleshooting is to apply voltmeter across crankcase
heater leads to see if heater voltage is on. Do not touch
heater. Carefully feel area around crankcase heater. If
warm, crankcase heater is probably functioning. With
power off, and heater leads disconnected, check across
leads with ohmmeter. Do not look for a specific resistance
reading. Check for resistance or an open circuit. Change
heater if an open circuit is detected.
Service Valves — The service valves in the condensing
unit come from the factory frontseated This means the
refrigerant charge is isolated from the line set connec¬
tion ports. To prevent damage to the valve, use a wet cloth
or other accepted heat sink material on the valve before
brazing.
The service valves must be backseated (turned counter¬
clockwise until seated) before the service port caps can be
removed and hoses of gage manifold connected. In this
position, refrigerant has access from and through
outdoor and indoor unit. The service valve cannot be
8

field repaired, therefore only a complete valve or valve
stem and service port caps are available for replacement.
AccuRater® (Bypass Type) Servicing — See
Fig. 4 for bypass type AccuRater components. The piston
has a refrigerant metering hole through it. The retainer
forms a stop for the piston in the refrigerant bypass mode,
and a sealing surface for liquid line flare connection. To
check, clean or replace piston:
1. Shut off power to unit.
2. Pump unit down using Pumpdown Procedure
described previously.
3. Remove liquid line flare connection from AccuRater.
4. Pull retainer out of body, being careful not to scratch
flare sealing surface. If retainer does not pull out
easily, carefully use locking pliers to remove retainer.
5. Slide piston out by inserting a small soft wire, with
small kinks, through metering hole. Ensure metering
hole, sealing surface around piston cones and fluted
portion of piston are not damaged.
6. Clean piston refrigerant metering hole.
7. Replace retainer O-ring before reassembling bypass
type AccuRater. Carrier O-ring part number is
99CC501052.
Refrigerant Charging
A CAUTION
To prevent personal injury, wear safety glasses and
gloves when handling refrigerant. Do not overcharge
system. This can cause compressor flooding.
A CAUTION
Service valves must be fully backseated to close
service port. There is no Schrader valve at the service
port and failure to backseat the valve could result in
loss of system charge or personal injury.
To check and adjust charge during cooling season, use
Tables 4 and 5 and the following procedure:
1. Operate unit a minimum of 15 minutes before check¬
ing charge.
2. Measure suction pressure by attaching a gage to
suction valve service port.
3. Measure suction line temperature by attaching a
service thermometer to unit suction line near suction
valve. Insulate thermometer for accurate readings.
4. Measure outdoor coil inlet air dry-bulb temperature
with a second thermometer.
5. Measure indoor coil inlet air wet-bulb temperature
with a sling psychrometer.
6. Refer to Table 4. Find air temperature entering
outdoor coil and wet-bulb temperature entering
indoor coil. At this intersection note the superheat.
7. Refer to Table 5. Find superheat temperature and
suction pressure, note suction line temperature.
8. If unit has higher suction line temperature than
charted temperature, add refrigerant until charted
temperature is reached.
9. If unit has lower suction line temperature than
charted temperature, bleed refrigerant until charted
temperature is reached.
10. If air temperature entering outdoor coil or pressure
at suction valve changes, charge to new suction line
temperature indicated on chart.
11. This procedure is valid, independent of indoor air
quantity.
Table 4 — Superheat Charging Table
(Superheat Entering Suction Service Valve)
OUTDOOR
TEMP (F)
50
INDOOR COIL ENTERING AIR (F) WB
52 54 56
58
60
62
64
66 168
70
n
74 76
55
12 14 17 20
23
26 29
32 35 37
40
42 W5
60
10 12 15
18 21
24 27
;30 63
135 138
40 43
65
10 13
16
19
21
24
27
30 33
m 38
41
70
10
13
16 19
21
24
27
30
p3
36
69
75
12 15 18 21 24
28 K31 34
37
80
12 15
18 21 25
28
31
35
85
11
15 19
22
66
30
33
90
13 16 20 £4 27
31
95 10
14
18 £2 25 29
100
12
15
60
23
27
105
13
17
22
26
110
11
15
20
25
115
14
|18
23
— Do not attempt to charge system under these conditions or
refrigerant slugging may occur
Table 5 — Required Suction-Tube Temperature (F)
(Entering Suction Service Valve)
SUPERHEAT
SUCTION PRESSURE AT SERVICE PORT (psig)
TEMP (F)
61.5
64.2
67.1
o
o
73.0
76.0 ~>i
CO ro
82.4
85.7
0
35 37 39 41 43
45 47
49
51
2
37 39
41
43 45 47
49
51
53
4
39
41 43
45
47
49 51
53 55
6
41
43
45
47 49
51
53
55 57
8 43 45
47
49 51 53 55
57 59
10 45 47 49 51 53 55 57
59 61
12 47 49
51
53 55 57 59
61 63
14 49 51
53
55
57
59 61
63
65
16 51 53
55 57 59
61 63
65
67
18 53 55
57
59 61 63 ~65^ 67 69
20 55
57 59
61
63
65
67
69
71
22
57 59 61 63 65 67
69 71 73
24 59 61
63
65
67
69 71
73
75
26 61 63
65 67
69 71 73
75
77
28
63 65
67
69
71
73
IE
77 79
30 65
67 69 71 73
75 79 _81_
32
67 69 71 73 75 77
79 81 83
34 69 71 73 75
77
79 81
83 85
36
71 73 75 77 79 81 83
85
87
38
73 75
77
79 81 83 85
87 89
40
75 77 79 81 83 85 87
89 91
Time Guard® II Device — Accessory Time Guard
II device is shipped in 6-pack units. Apply it to Carrier
38HD units to protect the unit compressor from short
cycling. See Fig. 9. The device prevents short cycling by
providing a 5-minute delay ( ± 2 minutes) before restart¬
ing a compressor after shutdown for any reason. On
normal start-up, the 5-minute delay occurs before the
thermostat closes. After the thermostat closes, the Time
Guard II device then has a 3-second delay prior to
contactor closure.
INSTALLATION — Install the Time Guard II device in
the 24-v control circuit, locating it in the space provided
at the front of the control box, using the screws provided.
9

MAINTENANCE
BLK DENOTES CLOSED CONTACTS
Fig. 9 — Time Guard II Sequence Chart
TIME GUARDH
—vio—
Tl T3 T2
1
YEL
COMPRESSOR
LOCKOUT
XD Cj> <D--blu-
<D d
Lbrn-
BLK-
BRN^r COMMON
TO THERMOSTAT
Fig. 10 — Wiring Diagram
See Fig. 10. Wire the device in series between the
compressor lockout (CLO) and the unit thermostat as
shown on unit wiring diagram.
A CAUTION
Before performing recommended maintenance, be
sure unit main power switch is turned off. Failure to
do so may result in electric shock or injury from
rotating fan blade.
Lubrication
COMPRESSOR contains factory oil charge. Replace oil
when lost. See Table 2 for oil recharge and refer to
Carrier Standard Service Techniques Manual, Chapter 1,
page 1-21, for oil recharging procedure. Use Carrier
PP33-1, Texaco WF-32 or Suniso 3GS oil.
FAN MOTOR BEARINGS — Oiling holes are provided
at each end of condenser fan motor. Remove fan motor
and lubricate motor with 32 drops (16 drops per hole) of
SAE-10 nondetergent oil at intervals described below:
a. Annually, when environment is very dirty, ambient
temperature is higher than 105 F and average unit
operating time exceeds 15 hours a day
b. Every 3 years when environment is reasonably clean,
ambient temperature is less than 105 F and unit
operating time averages 8 to 15 hours a day.
c. Every 5 years when environment is clean, ambient
temperature is less than 105 F and unit operating time
averages less than 8 hours a day.
Cleaning Coils — Coils should be washed out with
water, or blown out with compressed air. The blow-thru
design causes dirt and debris to build up on the inside of
the coils.
Remove the wire from terminal 2 on the compressor
lockout and connect the violet wire from T2 on the Time
Guard II device to terminal 2 on the compressor lockout.
Connect the wire removed from terminal 2 on the com¬
pressor lockout to yellow wire T1 on the Time Guard II
device. Connect black wire T3 on Time Guard II device
to common.
Compressor Lockout — Units with compressor
lockout protective device shut down on any safety trip.
Determine reason for safety trip. To restart, turn the
thermostat to OFF and then to COOL.
Clean coil annually or as required by location or
outdoor air conditions. Inspect coil monthly, and clean as
required. Fins are not continuous through coil sections.
Dirt and debris may pass through first section, become
trapped between the row of fins and restrict condenser
airflow. Use a flashlight to determine if dirt or debris has
collected between coil sections. Clean coil as follows:
1. Turn off unit power.
2. Using a water hose, or other suitable equipment, flush
coil from the outside to remove dirt Be sure to flush
all dirt and debris from drain holes in base of unit.
Fan motors are waterproof.
10