Carrier 380B - Manual (Page 3)

Table 2 — Installation Data (Fig. 1)
required replacement piston is factory supplied with
specified 38QB outdoor unit. Replace piston as
described under AccuRater™ Servicing on page 13.
Top Cover Removal — Top cover can be removed
for wiring or servicing heat pump. Loosen decora­
tive strip and slide down off screw heads. Remove
3 screws in connector plate and 2 screws on front of
unit. Loosen remaining 4 screws. Lift top from unit
(See Fig. 1).
Step 2 — Mount Outdoor Heat Pump
ON THE GROUND: MOUNT ON A SOLID,
LEVEL CONCRETE PAD (See Fig. 1). Swing 3
legs down and lock in position, except when using
accessory rack. Use accessory heat pump rack
(Fig. 2) in areas where prolonged subfreezing tem­
peratures or heavy snow occur. (Refer to installation
instructions included with rack.) Drainage holes in
unit base must not be obstructed.
ON THE ROOF: MOUNT UNIT ON A LEVEL
PLATFORM OR FRAME. Proper precaution
must be taken for support of unit in roof design.
Elevate unit for proper clearance as described under
ground installation above. Plan roof design and
water drainage to prevent unit from setting in water.
Flash all roof openings to prevent leaks.
Roof mounted units exposed to winds above
5 mph (8 km/ h) may require protective wind baffles
(field fabricated) to achieve adequate defrost.
Step 3 — Make Piping Connections
— The
38QB can be connected to indoor units using
Carrier accessory tubing package or field-supplied
tubing of refrigerant grade. See Table 2 for unit
piping connection type and size. See Table 3 for
accessory tubing sizes. For requirements beyond
50 ft (15.2 m), obtain information from local Carrier
distributor. Isolate interconnecting tubing from
framing and ductwork or where tubing runs thru
stud spaces, enclosed ceilings or pipe chases. Use
isolation type hangers. Fig. 3, since rigid fastening
transmits pulsations to structure creating objec­
tionable sound.
A capacity reduction will result if accessory tub­
ing is used in 38QB042 systems. For example, when
a 25-ft (7.6 m) 7/8-in. (22 mm) accessory package is
used, there is a capacity reduction of 1-1/2 percent.