![background image](http://html1.mh-extra.com/html/carrier/30gt080-420/30gt080-420_installation-start-up-and-service-instructions-manual_2562301057.webp)
SERVICE
ELECTRIC SHOCK HAZARD.
Turn off all power to unit before servicing.
The ON-OFF switch on control panel does
not shut off control power; use field
disconnect.
Diagnostics and Troubleshooting —
Refer to Con-
trols and Troubleshooting literature.
For field service use, a Ground Fault Interrupter (GFI) con-
venience outlet is available as a field-installed accessory for
all units. The GFI is rated for 15 amps. However, in units
with active cooler heaters, only 8 amps are available.
Refrigerant Circuit
LEAK TESTING — Units are shipped with complete op-
erating charge of refrigerant R-22 (see Tables 2A-3B) and
should be under sufficient pressure to conduct a leak test. If
there is no pressure in the system, use standard refrigeration
practices to search for the leak. Repair the leak using good
refrigeration practices. After leaks are repaired, system must
be evacuated and dehydrated.
DEHYDRATION — Refer to Carrier Standard Service Tech-
niques Manual, Chapter 1, Refrigerants, Sections 6 and 7 for
details. Do not use compressor to evacuate system.
REFRIGERANT CHARGE (Refer to Tables 2A-3B) — Im-
mediately ahead of filter drier in each circuit is a factory-
installed liquid line service valve. Each valve has a
1
⁄
4
-in.
Schrader connection for charging liquid refrigerant.
Charging with Unit Off and Evacuated — Close liquid line
service valve before charging. Weigh in charge shown on
unit nameplate (also in Tables 2A-3B). Open liquid line serv-
ice valve; start unit and allow it to run several minutes fully
loaded. Check for a clear sight glass. Be sure clear condition
is liquid and not vapor.
Charging with Unit Running — If charge is to be added while
unit is operating, all condenser fans and compressors must
be operating. It may be necessary to block condenser coils
at low ambient temperatures to raise condensing pressure to
approximately 280 psig (1931 kPa) to turn all condenser fans
on. Do not totally block a coil to do this. Partially block all
coils in uniform pattern. Charge each circuit until sight glass
shows clear liquid, then weigh in amount over a clear sight
glass as listed in Tables 2A-3B.
IMPORTANT: When adjusting refrigerant charge, cir-
culate fluid through cooler continuously to prevent freez-
ing and possible damage to the cooler. Do not over-
charge, and never charge liquid into low-pressure side
of system.
Electronic Components
CONTROL COMPONENTS — Unit uses an advanced elec-
tronic control system that normally does not require service.
For details on controls refer to Controls and Troubleshoot-
ing literature.
30GT080-110 AND 230B-315B UNIT CONTROL BOX —
Viewed facing compressors, main control box is at left end
of unit. All incoming power enters through main box. Con-
trol box contains power components and electronic controls.
Outer panels are hinged and latched for easy opening. Re-
move screws to remove inner panels. Outer panels can be
held open for service and inspection by using door retainer
on each panel. Remove bottom pin from door retainer as-
sembly, swing retainer out horizontally, engage pin in one of
the retainer ears and the hinge assembly.
30GT130-210, 230A-315A, AND 330A/B-420A/B UNIT
CONTROLAND MAIN POWER BOXES — The main power
box is on the cooler side of the unit, and the control box is
on the compressor side. Outer panels are hinged and latched
for easy opening. Remove screws to remove inner panels.
Compressors —
If lead compressor on either refriger-
ant circuit becomes inoperative for any reason, circuit is locked
off and cannot be operated due to features built in the elec-
tronic control system. Do not attempt to bypass controls to
force compressors to run.
COMPRESSOR REMOVAL — Access to the pump end
of the compressor is from the compressor side of the unit.
Access to the motor end of the compressor is from the inside
of the unit. All compressors can be removed from the com-
pressor side of the unit.
IMPORTANT: All compressor mounting hardware and
support brackets removed during servicing must be re-
installed prior to start-up.
Following the installation of the new compressor:
Tighten discharge service valve bolts to —
Compressor(s)
20 to 25 ft-lb (27 to 34 N-m)
06E250
80 to 90 ft-lb (109 to 122 N-m)
06E265,275,299
Tighten suction service valve bolts to —
80 to 90 ft-lb (109 to 122 N-m)
06E250
90 to 120 ft-lb (122 to 163 N-m)
06E265,275,299
Tighten the following fittings to —
120 in.-lb (13.5 N-m)
High Pressure Switch
120 in.-lb (13.5 N-m)
Loss of Charge Switch
OIL CHARGE (Refer to Tables 2A-3B) — All units are fac-
tory charged with oil. Acceptable oil level for each compres-
sor is from
1
⁄
8
to
3
⁄
8
of sight glass (see Fig. 18).
When additional oil or a complete charge is required, use
only Carrier-approved compressor oil.
Approved oils are as follows:
Petroleum Specialties, Inc. — Cryol 150 (factory oil charge)
Texaco, Inc.
— Capella WF-32
Witco Chemical Co.
— Suniso 3GS
COMPRESSOR
OIL REQUIRED
Pts
L
06E250
14
6.6
06E265
19
9.0
06E275
19
9.0
06E299
19
9.0
Do not reuse drained oil and do not use any oil that has
been exposed to atmosphere.
57