Carrier 38HQ - Manual (Page 3)

Table 3 ^ Carrier-Approved 38HQ Systems
INDOOR
COMPR
OUTDOOR
COIL
INDOOR FAN COIL
INDOOR
ACCURATER™
OUTDOOR
ACCURATER i
MAX HEIGHT (ft)
INDOOR UNITS
SECTION PISTON PISTON Above Below
38HQ
NO. NO.
Outdoor Coil
120 940*
L
L
40FS160
f0AQ030
f0AQ036t
28HQ,VQ030t**
28HQ,VQ036**
28HQ,VQ036
59 46
127 940
40AQ030t
40AQ036Ì
— j 28HQ,VQ030**
— 28HQ,VQ036t*‘
40FS160 1 28HQ,VQ036
40DQ030
63 59
134 940
40FS160
40AQ036
28HQ,VQ036**
28HQ,VQ036
70 59
50 50
140 960
40FS160
40FS200
28HQ,VQ042**
28HQ,VQ042
28HQ,VQ042
40QB042
76 63
146 960
40FS200
40FS220
28HQ,VQ048t**
28HQ,VQ048t
28HQ,VQ048
40QB048
82 63
^Change AccuRater Piston to No 46 in Outdoor Coil 38HQ940
when used in combination with Indoor Compressor Section
38HQ120
fWhen the system consists of 38HQ120 Compressor Section/
38HQ940 Outdoor Coil/ and 40AQ036 Indoor Fan Coil, the
factory-installed No 59 AccuRater piston must be removed from
the Outdoor Coil and installed in the Indoor Section As noted
above, a No 46 AccuRater piston is installed in the Outdoor Coil
Outdoor Coil — Make provisions for condensate
drainage and defrost water disposal whether unit is
installed on ground, roof or off-the-wall platform.
(Ensure unit basepan drainage holes are not
blocked.) See Mount Outdoor Coil for details. Roof
installation method for 38HQ depends on building
construction
and special requirements of local
codes. Make sure roof can support unit weight.
Indoor Compressor Section — Locate unit in base­
ment, garage or utility room. Indoor locations
within the living space are not recommended. Base­
ment installations also require careful planning to
avoid areas directly under bedrooms, living
rooms, etc.
Insert felt isolation pad (factory supplied) be­
tween unit and a rigid mounting base to absorb
vibration.
Isolate interconnecting tubing from
framing and ductwork or where tubing runs thru
stud spaces, enclosed ceilings or pipe chases. Use
isolation type hanger. Fig. 3, since rigid fastening
transmits pulsation to structure creating objection­
able sound.
System Refrigerant Control on 38HQ units and
matching Carrier indoor fan coil units is a factory-
installed Accu-Rater™ device (bypass type). Bypass-
type AccuRater components are shown in Fig. 26.
The AccuRater piston has a refrigerant metering
hole thru it, and is field replaceable. Table 3 indi­
cates indoor units that require piston replacement
when used with specified 38HQ units. Replace
for all 38HQ120 combinations Discard the AccuRater piston
which was factory installed in the Indoor Fan Coil
tindoor units that require replacement of AccuRater refrigerant
control piston for optimum performance when used with speci­
fied 38HQ sections Required piston is shown in table and is
supplied with 38HQ compressor section for field installation
**Used in systems with non-specified indoor air moving unit
Fig. 3 — Refrigerant Line Hangers
piston as described under AccuRater Servicing
on page 16.
Step 2 — Mount Outdoor Coil
A heat pump rack for the outdoor section is avail­
able as an accessory. See Fig. 5 and Table 4. This
rack is easily assembled in the field and predrilled
to accommodate the outdoor coil (as described in
the Installation Instructions enclosed with the rack).
An alternate method of installing the outdoor sec­
tion is described in the following paragraphs.
ON THE GROUND; MOUNT OUTDOOR COIL
ON A SOLID, LEVEL CONCRETE PAD. See
Fig. 4 for pad dimensions. Position unit so that
coil drainage holes in basepan overhang the pad.
(See Fig. 1 for drainage hole location.) See that pad