CHECK ACCURATER® METERING DEVICE — The cor-
rect AccuRater (bypass type) refrigerant control is required
for system capacity optimization. An AccuRater device with
field-replaceable piston (see Fig. 4) is supplied on indoor coil
and at service valve of outdoor unit. Refer to the AccuRater
metering device table in separate indoor unit installation in-
structions to determine the correct AccuRater piston size re-
quired for the heat pump/indoor unit system being installed.
Note that one of 2 types of AccuRater controls can be found
on the indoor unit, and that Type B AccuRater devices are
used on 38QR018C-060C heat pumps. Do not interchange
components between the AccuRater device types. Matching
of heat pump with indoor unit may require field replacement
of piston. Replace pistons, if required, before connecting re-
frigerant lines. Piston replacement instructions are included
in separate indoor unit installation instructions. After system
installation is complete, see Refrigerant Charging section on
page 10 to check and/or adjust refrigerant charge.
Step 2 — Rig and Mount Unit
MOUNTING ON GROUND — Mount unit on a solid, level
concrete pad. Position unit so water or ice from roof does
not fall directly onto unit. Use accessory snow rack (part no.
38QR900001 or -011) or ice stand (part no. 38QR900021 or
-031) (see Fig. 2, 3) where prolonged subfreezing tempera-
tures or heavy snow occurs. Refer to separate installation
instructions packaged with the accessories. If conditions or
local codes require unit be fastened to pad, 6 field-supplied
tiedown bolts should be used and fastened through slots pro-
vided in unit mounting feet.
MOUNTING ON ROOF — Mount unit on a level platform
or frame at least 6 in. above roof surface. Isolate unit and
tubing from structure.
RIGGING
Be sure unit panels are securely in place prior to
rigging.
Keep unit upright. Lift unit using sling. Use cardboard or
padding under sling, and spreader bars to prevent sling dam-
age to unit. See Fig. 5. See Fig. 2 and 3 for center of gravity
reference. Install unit so that coil does not face into prevail-
ing winds. If this is not possible and constant winds above
25 mph are expected, use Accessory Wind Baffle (part no.
38QR900041 or -051). See installation instructions pro-
vided with accessory kit.
Step 3 — Complete Refrigerant Piping Connec-
tions —
Outdoor units may be connected to indoor units
using field-supplied tubing of refrigerant grade and condi-
tion. See Table 1 for correct line sizes. Do not use less than
10 ft of interconnecting tubing.
DO NOT BURY MORE THAN 36 IN. OF REFRIG-
ERANT PIPE IN THE GROUND. If any section of pipe
is buried, there must be a 6-in. vertical rise to the valve
connections on the outdoor unit. If more than the rec-
ommended length is buried, refrigerant may migrate to
cooler, buried section during extended periods of sys-
tem shutdown. This causes refrigerant slugging and could
possibly damage compressor at start-up.
When more than 50 ft of interconnecting tubing and more
than 30 ft of vertical lift is used, refer to Part 3 of Carrier
System Design Manual for design details, or contact your
local distributor.
TYPE A
NOTE: Arrow on AccuRater body points in
free flow
direction, away
from the indoor coil.
TYPE B
Fig. 4 — AccuRater® (Bypass Type) Metering De-
vice Components
Fig. 5 — Lifting Unit With Sling
4
