Carrier 380B - Manual (Page 5)

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REPLACE THE ACCURATER™ REFRIG­
ERANT CONTROL PISTON IN THE INDOOR
COIL AS REQUIRED before connecting refrig­
erant lines. See Table 1. Correct piston is supplied
with 38QB unit. For piston replacement instruc­
tions, see AccuRater Servicing on page 13.
CONNECT REFRIGERANT LINES to fittings on
unit suction and liquid service valves (Fig. 1).
Liquid service valve has flare fitting; suction service
valve has Compatible Fitting. Make suction line
connection first. Slide flare nut on liquid line, then
flare and connect liquid line. Use a maximum
torque of 15ft-lb (20N/m) to tighten flare nut.
(Do not disassemble AccuRater.) Unit Compatible
Fitting permits mechanical or sweat connection as
described below.
When a 7/8-in. (22.22 mm) field-supplied suction
line is used on 38QB036, a field-supplied 3/4-in.
(19.05 mm) to 7/8-in. (22.22 mm) suction line
adapter must be provided (not required if 38LS
accessory tubing is used).
When a 1-1/8 in. (28.57 mm) field-supplied suc­
tion line is used on 38QB042, use accessory adapter
28VQ900001 or other field-supplied connection.
Sweat connect refrigerant suction line to 1-1/8 in.
(28.57 mm) end of adapter. Connect 3/4-in.
(19.06 mm) end of adapter to unit suction line
Compatible Fitting.
Mechanical Connection to Compatible Fitting
(Mate one set of connections at a time.)
1. Loosen nut on Compatible Fitting one turn. Do
not remove.
2. Remove plug and be sure O-ring is in the groove
inside the Compatible Fitting.
3. Cut tubing to correct length.
4. Insert tube into Compatible Fitting until it
bottoms.
5. Tighten nut until it bottoms on back coupler
flange. Keep tube bottomed in Compatible
Fitting while tightening nut.
Sweat Connection to Compatible Fitting (Use
refrigerant grade tubing.)
1. Remove locking nut, rubber O-ring and Schrader
core from valve.
2. Cut tubing to correct length.
3. Insert tube into Compatible Fitting. Wrap top
and bottom of service valves in wet cloth to pre­
vent damage by heat. Solder with low tempera­
ture ([430 F] [221 C]) silver alloy solder.
4. Replace Schrader core.
5. Evacuate or purge system with field-supplied
refrigerant.
Step 4 — Make Electrical Connections
— Field
wiring must comply with local and national fire,
safety and electrical codes. Voltage to unit must be
within ± 10% of voltage indicated on nameplate.
Contact local power company for correction of
improper line voltage.
Do not apply units in system where voltage may
fluctuate above or below permissible limits.
When making electrical connections, provide
clearance at unit for refrigerant piping connections.
See Table 4 for recommended wire and fuse sizes.
Fig. 4 — Urte Power Connections
Table 4 — Electrical Data (60 Hz)
UNIT
38QB
V/PH
OPER
VOLTAGE*
COMPRESSOR FAN
FLA
BRANCH CIRCUIT
Min Wire
Size
(AWG)t
Max Wire Min Gnd
Wire Sizet
Max Fuse or
HACR Type
CktBkrAmps“
MCA
Max Min LRA RLA (ft)
018
024
030
036
208-230/1 254 197
48
66
82
88
124
155
15 5
20 6
1.25
2.40
2 40
2 40
14
12
12
10
33
32
32
39
m
14
12
12
10 25
35
35
45 168
21 8
21 8
28 2
042 230-1 254 207 98 199 2 40 10 44 10 45 27.3
AWG — American Wire Gage
FLA — Full Load Amps
HACR — Heating, Air Conditioning and Refrigeration
LRA — Locked Rotor Amps
MCA — Minimum Circuit Amps
RLA — Rated Load Amps
‘Permissible limits of the voltage range at which the unit will
operate satisfactorily.
tCopper wire sizes based on 60 C Use copper or copper-clad
aluminum wire only Use latest NEC for copper-clad aluminum
conductor sizing
{Required when using nonmetallic conduit.
“Maximum dual element size
NOTE: All units have 24-v control circuit which requires external
power source