Maintenance - Carrier 30XA080-500 Controls, Start-Up, Operation, Service And Troubleshooting Instructions

Charging with Unit Off and Evacuated -- Close liquid line
service valve before charging. Weigh in charge shown on unit
nameplate. Open liquid line service 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 vapoc
Charging with Unit Running -- If charge is to be added while
unit is operating, all condenser fans and compressol_ must be
operating. It may be necessa U to block condenser coils at low
ambient temperatures to raise condensing pressure to approxi-
mately 198 psig (1365 kPa) to turn all condenser fans on. Do not
totally block a coil to do this. Partially block all coils in unif(mn
pattern. Chtu_ge each circuit until sight glass shows dear liquid,
and has a liquid line temperature of 103 F (39 C) for 30XA080-
350 units and 108 F (42 C) for 30XA400-500 units.
Add 5 lb (2.3 kg) of liquid chtu_ge into the entering filter
drier using the fitting located on the tube entering the bottom of
the coolec This fitting is located between the electronic expan-
sion valve (EXV) and the coolel:
Allow the system to stabilize trod then recheck the liquid
temperature. If needed, add additional liquid charge, 5 lb
(Z3 kg) at a time, allowing the system to stabilize between
each charge addition. Slowly add charge as the sight glass
begins to clear to avoid overcharging.
IMPORTANT: When adjusting refrigerant chtuge, circu-
late fluid through cooler continuously to prevent freezing
and possible dmnage to the coolel: Do not overcharge, and
never charge liquid into the low-pressure side of system.
Safety DeviceS--The
30XA chillers cont;fin many
safety devices and protection logic built into the electronic
control Following is a description of the major safeties.
COMPRESSOR PROTECTION
Motor Overload -- The compressor protection modules
(CPM) protect each compressor against overcurrent. Do not
bypass the current transducel_ or make any changes to the
factory-installed and configured headers. The configuration of
these headers defines the Must Trip Amps (MTA) at which the
CPM will turn the compressors off. Determine the c;mse for
trouble and correct the problem before resetting the CPM. See
Appendix C for MTA settings and configuration headers.
Each CPM bo;ud also reads the status of each compressor's
high-pressure switch. All compressors have factory-installed
high-pressure switches. See Table 37.
Table 37 -- High-pressure Switch
Settings
SWITCH SETTING
UNIT
psig ] kPa
30XA 304.5 _+14.5 2099 _+100
If the switch opens during operation, the compressor will be
shut down. The CPM will reset automatic_flly when the switch
closes, however, a manual reset of the control is required to
restart the compressor:
OIL SEPARATOR HEATERS -- Each oil separator circuit
has a heater mounted on the underside of the vessel. The heater
is deenergized anytime the compressor is on. If the compressor
is off and outdoor-air temperature (OAT) is greater than 100 F
(37.8 C) the heater is deenergized. The heater will also be
deenergized if OAT - SST >32 F (17.8 ° C) and the OAT -
LWT > 32F (17.8° C).
COOLER PROTECTION
Low Water Temperature -- Microprocessor is programmed
to shut the chiller down if the leaving fluid temperature drops
below 34 F (1.1 C) for water or more than 8 ° F (4.4 ° C) below
set point for Fluid Type = brine. When the fluid temperature
rises 6 ° F (3.3 ° C) above the leaving fluid set point, the safety
resets and the chiller restarts. Reset is automatic as long as this
is the first occurrence of the day.
IMPORTANT: If unit is installed in an area where
ambient temperatures fall below 32 F (0 ° C), a suit-
able corrosion-inhibited antifreeze solution or cooler
heater must be used in the chilled water circuit.
Relief Devices
-- Fusible plugs are located in each cir-
cuit between the condenser and the liquid line shutoff valve.
PRESSURE RELIEF VALVES -- Valves ;ue installed in each
circuit and are located on all coolers. These valves are
designed to relieve if an abnormal pressure condition _uises.
Relief valves on _fll coolers lelieve at 220 psi (1517 kPa).
These valves should not be capped. If a valve lelieves, it
should be replaced. If the valve is not replaced, it may relieve
at a lower pressure, or leak due to trapped dirt from the system
which may prevent resealing.
Plessure relief valves located on cooler shells have 3/4-in.
NPT connections for lelief. Some local building codes require
that relieved gases be exhausted to a specific location. This
connection _fllows conformance to this requirement.
MAINTENANCE
Recommended Maintenance Schedule -- The fol-
lowing
are only recolmnended guidelines. Jobsite conditions
may dictate that maintenance schedule is performed more often
than recommended.
Routine:
For machines with E-coat condenser coils:
• Check condenser coils for debris; clean as necessary with
Carrier approved coil cleaner.
• Periodic clean water rinse, especially in coastal and
industrial applications.
Every month:
• Check condenser coils for debris; clean as necessary with
Carrier approved coil cleaner.
• Check moisture indicating sight glass for possible refrig-
erant loss and presence of moisture.
Every 3 months (for all machines):
• Check refrigerant charge.
• Check all refrigerant joints and valves for refrigerant
leaks; repair as necessary.
• Check chilled water flow switch operation.
• Check all condenser fans for proper operation.
• Check oil filter pressure drop.
• Check oil separator heater operation.
Every 12 months (for all machines):
• Check all electrical connections; tighten as necessary.
• Inspect all contactors and relays; replace as necessary.
• Check accuracy of thermistors; replace if greater than
_+2 ° F (1.2 ° C) variance fiom calibrated thermometer.
• Check accuracy of transducers; replace if greater than
_+5psi (34.47 kPa) variance.
• Check to be sure that the proper concentration of anti-
freeze is present in the chilled water loop, if applicable.
• Verify that the chilled water loop is properly treated.
• Check refrigerant filter driers for excessive pressure
drop; replace as necessary.
• Check chilled water strainers, clean as necessary.
• Check cooler heater operation.
• Check condition of condenser fan blades and that they
are securely fastened to the motor shaft.
• Perform Service Test to confirln operation of all components.
• Check for excessive cooler approach (Leaving Chilled
Water Temperature - Saturated Suction Temperature) which
may indicate fouling. Clean cooler vessel if necessary.
• Obtain oil analysis; change as necessmy.
TROUBLESHOOTING
See Table 38 for an abbreviated list of sylllptolllS, possible
causes and possible remedies.
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