Carrier 38AD Installation, Start-Up And Service Instructions Manual page 2

Table 1 — Physical Data (60-Hz)
UNIT 38AD 012 014
016
OPER WT (lb)
770
805 970
REFRIGERANT 22 22 22
COMPRESSOR Recip Hermetic 6 Cyl; 1750 Rpm
Model No.
06DD328 06DD537 06DD537
Oil (pts) Suniso 3GS
or Capella Bl
10 10
10
Crankcase Htr Watts 75 75 75
Unloader Setting
Load
70
±
1 psig 70 ± 1 psig
70 ± 1 psig
Unload
60 ± 2 psig
60 ± 2 psig 60 i 2 psig
OUTDOOR AIR FANS Axial Flow; Direct Drive
No. ...Rpm
2...1085 2 ..1085 3...1120
Diam (in.) 22 22
22
Motor Hp (NEMA)
l/2
%
l/2
Nom Cfm Total
8800 8000
13,000
CONDENSER COIL
Face Area (sa ft)
Storage Cap. (lb)*
19 1 19.1
26.2
17.7
26.5
51
CONTROLS
Pressurestat Settings
High Cutout
400 ± 5 psig 400 ± 5 psig 364 ± 5 p s i g
Cut-In 300 ±20 psig 300
±
5 psig 264 ± 15 psig
Low Cutout
29 ± 5 psig
29 ± 5 psig
29 ± 5 p sig
Cut-In 64 ± 10 psi g 64 + 10 psig
64 ± 5 psig
Fan-Cycling Thermo.
No. 2 Opens
Closes
60 ± 2 F
60 ± 2 F 70 F
65 ± 4 F 65 ± 4 F
75 F
No. 3 Opens
— -
57 F
Closes
- -
62 F
FUSIBLE PLUG 200 F
200 F
200 F
*Storage capacity is with condenser 80% full of liquid R-22 at 130 F
for 38AD012 and 014, and 120 F for 38AD016.
Fan-Cycling Thermostat
temperature sensing bulb
and coiled capillary are taped to compressor conduit
in compressor compartment for shipment. Carefully
remove tape and uncoil capillary. Route bulb and
capillary behind compressor and out of compressor
compartment thru space under right-hand condenser
coil. Do not kink or damage capillary or sensing bulb.
Position sensing bulb in inlet airstream. With
mounting clamp and hardware provided in parts
package, secure sensing bulb to lower tube sheet near
compressor so that it does not touch coil fins. Be sure
airstream across bulb is unrestricted and that bulb
does not receive direct sunlight.
Refrigerant Line Sizes
will depend on length of piping
required between condensing unit and evaporator.
Consideration must be given to liquid lift and to
compressor oil return (see Table 2). Refer to Part 3 of
Carrier System Design Manual for design details and
line sizing.
Refer to Evaporator Installation Instructions for
additional information.
Refrigerant Drier and Moisture Indicator
— A filter-
drier and a liquid-moisture indicator are shipped with
unit for field installation (Table 2). Install according
to manufacturer's instructions.
Receiver
— No receiver is provided with unit. It is
recommended that one not be used.
Piping Procedure
— Do not remove plastic dust plugs
from suction and liquid line stub in compressor
compartment until piping connections are ready to be
made. Pass nitrogen or other inert gas thru piping
while brazing, to prevent formation of copper oxide.
Install field-supplied thermostatic expansion
valve(s) to evaporator section. If two thermostatic
expansion valves are installed for two-step cooling,
install field-supplied liquid line solenoid valve
ahead of second expansion valve.
Install filter-drier in the common liquid line just
ahead of both expansion valves.
Table 2 — Liquid Line Data
UNIT
MODEL
38AD
MAX
ALLOW.
LIQUID
LIFT
(ft)
LIQUID LINE
Max Allow.
Press. Drop
(psi)
Max Allow.
T emp
Loss
(F)
Fi Iter-Drier
and Sight Glass
Flare Conn.*
(in.)
012
75 7 1.5
%
014
50 7 1.5
5/»
016
78 7 1.0 %
*lnlet and outlet
Safety Relief
— A fusible plug is located on com¬
pressor crankcase (Fig. 2). Do not cap this plug.
If local code requires additional safety devices,
install them as directed.
Fig. 2 — Tee Connection
Power Wiring
— Unit is factory wired for voltage
shown on nameplate. Provide an adequate fused
disconnect switch within sight of unit and 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, especially if
disconnect is not visible from unit. Disconnect
switch, fuses, and field wiring must comply with
National Electrical Code and local requirements.
Route power wires thru openings in unit
bottom panel to connections in unit control box as
shown on unit label diagram and Fig. 3. Unit must
be grounded.
Affix crankcase heater power warning sticker to
unit disconnect switch.
Fig. 3 — Main Power Supply