Carrier 38HQ - Manual (Page 5)

Since it is lightweight, the outdoor unit can be
mounted on a platform attached to or built out from
structure. Construct platform using drainage and
clearance recommendations above. Locate and con­
struct platform to avoid possible transfer of unit
vibration to structure.
ON THE ROOF: MOUNT OUTDOOR COIL ON
A LEVEL PLATFORM OR FRAME. Unit must
be elevated for proper clearance as described
under ground installation above. Roof design and
water drainage must be planned to prevent units
from setting in water. Flash all roof openings to
prevent leaks.
Step 3 — Mount Indoor Compressor Section
on a rigid, solid platform or concrete floor. Insert
1/4-in. asphalt impregnated felt pad (factory
supplied) between unit basepan and mounting
surface to provide full unit support and for vibra­
tion attenuation. (Do not use vibration isolator
under corners of basepan.)
Step 4 — Make Piping Connections — The
38HQ units can be connected to indoor fan coil
using Carrier accessory tubing package or field-
supplied tubing of refrigerant grade. See Tables 1
and 2 (with notes) for unit piping connection type,
size and line size recommendations and Table 4 for
accessory tubing sizes. Maximum allowable system
liquid line length is 100 feet. Maximum vapor line
length from compressor section to indoor coil is 50
feet. Maximum vapor line length from eompressor
section to outdoor coil is 50 feet.
A capacity reduction will result if accessory
tubing is used in 38HQ146 systems. For example,
when a 25-ft, 7/8-in. accessory tubing package is
used, there will be a capacity reduction of 1-1/2%.
For maximum capacity, use 1-1/8 in. vapor line as
recommended in Tables 1 and 2.
When other than 25 ft of interconnecting piping
is used, follow special requirements described in
Refrigerant Charging. Do not use less than 10 ft of
liquid line. Do not cut accessory 7/8-in. vapor line.
Bend or coil to fit.
Do not use damaged or contaminated tubing.
Always evacuate or purge indoor coil, compressor
section and tubing system (use field-supplied refrig­
erant, not unit refrigerant).
When making tubing conneetions, be sure to pro­
vide clearance at unit for electrical connections and
follow tubing isolation method. Step 1, page 3.
Table 4 — Accessories
PART WO DESCRIPTIOW
38CQ900081
38CQ900111
Honeywell Thermostat and Subbase — Automatic Changeover
Honeywell Thermostat and Subbase — Manual Changeover
38CQ900211 White Rodgers Thermostat and Subbase — Manual Changeover
38CQ900152 Solid State Time Guard 1 24 V (six 38CQ900141)
38HQ900011 Hot Shot Domestic Water Pre-Heater
38CQ900172
38RQ900091
Optimizer Control (six 38CQ900161, ref HH22AQ110)
Optimizer II Control (use with Outdoor Thermostat HH22AG110)
38RQ900032 Outdoor Thermostat — adjustable control for strip heaters, 48-in long Cap Tube
38HÛ900002 Outdoor Thermostat — adjustable control for strip heaters; 36-in long Cap Tube
38RQ900012
38RQ900072
Supplemental Heat Relay (six 38RQ900001 )
Heat Pump Mounting Stand (six 38RQ900061)
38RQ900081 Biflow Liquid Filter-Drier (six KH45LD077)
28VQ900011 Twelve 3/4- x 1-1/8 in Connection Adapters for 38HQ146
TUBING
TUBING PACKAGES
LENGTH LIQUID LINE SUCTION LINE COMPRESSOR
(ft) OD (in.) OD (in.) SECTION 38HQ
38LS934151 15
38LS934201 20
38LS934251 25
38LS934301 30 3/8 3/4 120, 127, 134
38LS934351 35
38LS934401 40
38LS934501 50
38LS978151 15
38LS978201 20
38LS978251 25
38LS978301 30 3/8 7/8*t 140, 146
38LS978351 35
38LS978401 40
38LS978501 50
‘Swaged at each end down to 3/4 i
fCapacity reduction may occur when
nch
7/8-in accessory tubing is used on 38HQ146
5