Carrier 48DU Series Installation Instructions Manual Download Page 28

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Step 8—Outdoor Coil, Indoor Coil, and Condensate
Drain Pan

Inspect the condenser coil, evaporator coil, and condensate drain
pan at least once each year.
The coils are easily cleaned when dry; therefore, inspect and clean

the coils either before or after each cooling season. Remove all
obstructions, including weeds and shrubs, that interfere with the

airflow through the condenser coil. Straighten bent fins with a fin
comb. If coated with dirt or lint, clean the coils with a vacuum

cleaner, using the soft brush attachment. Be careful not to bend the

fins. If coated with oil or grease, clean the coils with a mild detergent
and water solution. Rinse coils with clear water, using a garden hose.

Be careful not to splash water on motors, insulation, wiring, or air
filter(s). For best results, spray condenser coil fins from inside to

outside the unit. On units with an outer and inner condenser coil, be

sure to clean between the coils. Be sure to flush all dirt and debris
from the unit base.
Inspect the drain pan and condensate drain line when inspecting the
coils. Clean the drain pan and condensate drain by removing all

foreign matter from the pan. Flush the pan and drain trough with
clear water. Do not splash water on the insulation, motor, wiring, or

air filter(s). If the drain trough is restricted, clear it with a “plumbers

snake” or similar probe device.

Step 9—Outdoor Fan

UNIT OPERATION HAZARD

Failure to follow this caution may result in damage to unit

components.
Keep the outdoor fan free from all obstructions to ensure

proper cooling operation. Never place articles on top of the

unit.

CAUTION

!

1. Remove 4 screws holding outdoor grille and motor to top

cover.

2. Turn motor/grille assembly upside down on top cover to

expose fan blade.

3. Inspect the fan blades for cracks or bends.
4. If fan needs to be removed, loosen setscrew and slide fan off

motor shaft.

5. When replacing fan blade, position blade according to the

table shown in Fig. 23.

6. Ensure that set screw engages the flat area on the motor shaft

when tightening.

7. Replace grille.

 Infinity Top

A06035

UNIT SIZE

“A” DIMENSION

024

26

030

26

036

26

042

26

048

9

060

14

Fig. 23 -- Outdoor Fan Blade Clearance

Step 10—Electrical Controls and Wiring

Inspect and check the electrical controls and wiring annually. Be

sure to turn off the electrical power to the unit.
Remove access panel to locate all the electrical controls and wiring.

Check all electrical connections for tightness. Tighten all screw
connections. If any smoky or burned connections are noticed,

disassemble the connection, clean all the parts, re--strip the wire end

and reassemble the connection properly and securely.
After inspecting the electrical controls and wiring, replace all the

panels. Start the unit, and observe at least one complete cooling
cycle to ensure proper operation. If discrepancies are observed in

operating cycle, or if a suspected malfunction has occurred, check

each

electrical

component

with

the

proper

electrical

instrumentation. Refer to the unit wiring label when making these

checks.

Step 11—Refrigerant Circuit

Inspect all refrigerant tubing connections and the unit base for oil
accumulation annually. Detecting oil generally indicates a

refrigerant leak.
If oil is detected or if low performance is suspected, leak test all

refrigerant tubing using an electronic leak detector, or liquid--soap

solution. If a refrigerant leak is detected, refer to Check for
Refrigerant Leaks section.
If no refrigerant leaks are found and low performance is suspected,
refer to Checking and Adjusting Refrigerant Charge section.

Step 12—Indoor Airflow

The heating and/or cooling airflow does not require checking unless

improper performance is suspected. If a problem exists, be sure that
all supply-- and return--air grilles are open and free from

obstructions, and that the air filter is clean.

Step 13—Pressure Switches -- Refrigerant Circuit

Pressure switches are protective devices integrated into the control

circuit (low voltage). They shut off compressor if abnormally high
or low pressures are present in the refrigeration circuit. These

pressure switches are specifically designed to operate with Puron
(R--410A) systems. R--22 pressure switches must not be used as

replacements for the Puron (R--410A) system.
Loss--of--Charge (Low Pressure) Switch
This switch is located on the liquid line and protects against low

suction pressures caused by such events as loss of charge, low
airflow across indoor coil, dirty filters, etc. It opens if the system

pressure drops to about 20 psig. If system pressure is above this,
switch should be closed.
High--Pressure Switches (HPS & HPS2)
The high--pressure switches are located on the discharge line and
protects against excessive condenser coil pressure. HPS opens at

670 psig shutting down the compressor, while HPS2 opens at 565,
limiting the compressor to low--stage operation only.
High pressure may be caused by a dirty outdoor coil, failed fan

motor, or outdoor air recirculation.
To check switches:

1. Turn off all power to unit.
2. Disconnect leads on switch.
3. Apply ohm meter leads across switch. You should have

continuity on a good switch.

NOTE

: Because these switches are attached to refrigeration system

under pressure, it is not advisable to remove this device for
troubleshooting unless you are reasonably certain that a problem
exists. If switch must be removed, remove and recover all system
charge so that pressure gauges read 0 psi. Never open system
without breaking vacuum with dry nitrogen.

48D

U

Summary of Contents for 48DU Series

Page 1: ...Checking Cooling and Heating Control Operation 25 Checking and Adjusting Refrigerant Charge 25 Refrigerant Charge 25 No Charge 25 Low Charge Cooling 25 To Use Cooling Charging Charts 25 Non Communicat...

Page 2: ...w NOx units designed for California installations These models meet the California maximum oxides of nitrogen NOx emissions requirements of 40 nanograms joule or less as shipped from the factory and m...

Page 3: ...Support CTyp G E F G D E A05308 UNIT SIZE ODS CATALOG NUMBER A IN MM B IN MM C IN MM D IN MM E IN MM F IN MM G IN MM 024 030 CPRFCURB006A00 8 203 11 279 16 1 2 419 28 3 4 730 30 3 8 771 44 5 16 1126...

Page 4: ...4 A06323 Fig 5 48DU024 030 Unit Dimensions...

Page 5: ...5 A06324 Fig 6 48DU036 060 Unit Dimensions...

Page 6: ...OIL Rows Fins in Face Area sq ft 3 17 3 7 3 17 3 7 3 17 3 7 3 17 3 7 3 17 4 7 3 17 4 7 3 17 4 7 3 17 4 7 INDOOR FAN Nominal Airflow Cfm Comfort Variable based on Comfort Roll back see User Interface i...

Page 7: ...e for high capacity type Air filter pressure drop for non standard filters must not exceed 0 08 in wg Step 3 Provide Clearances The required minimum service clearances are shown in Fig 5 and 6 Adequat...

Page 8: ...strip screws when re securing the unit If a screw is stripped replace the stripped one with a larger diameter screw included WARNING Rigging Lifting of Unit 1 Bend top of brackets down approximately...

Page 9: ...Sheet Metal and Air Conditioning Contractors National Association SMACNA and Air Conditioning Contractors Association ACCA minimum installation standards for residential heating and air conditioning s...

Page 10: ...OUTLET C99013 Fig 9 Condensate Trap Step 8 Install Gas Piping The gas supply pipe enters the unit through the access hole provided The gas connection to the unit is made to the 1 2 in FPT gas inlet on...

Page 11: ...ot use a connector which has previously serviced another gas appliance WARNING 8 Check for gas leaks at the field installed and factory installed gas lines after all piping connections have been compl...

Page 12: ...HUMIDITY CONTROL COMFORT ROLLBACK ETC WILL BE LOST IF THE OAT IS NOT CONNECTED For detailed mounting instructions for the OAT sensor please refer to TSTATXXSEN01 B installation instructions catalog n...

Page 13: ...BLK GROUND LEAD SINGLE PHASE CONNECTIONS TO DISCONNECT PER NEC LEGEND NEC National Electrical Code Field Wiring Splice Connections NOTE Use copper wire only L1 L2 A06299 Fig 12 Line Power Connections...

Page 14: ...Supply fuse The CGA Canadian Gas Association units may be fuse or circuit breaker 2 Minimum wire size is based on 60 C copper wire I fother than 60 C wire is used or if length exceeds wire length in...

Page 15: ...orrectly positioned in fan orifice Top 1 3 of condenser fan blade should be within fan orifice venturi c Ensure fan hub is positioned correctly with respect to motor housing See Fig 23 d Make sure tha...

Page 16: ...can be replaced MOTOR TURNS SLOWLY 1 Low static pressure loading of blower while access panel is removed will cause blower to run slowly Particularly at low airflow requests This is normal do not ass...

Page 17: ...17 6 0 A06310 Fig 16 Wiring Schematic 48DU Single Phase 48DU...

Page 18: ...system defective switch or connections or inadequate combustion air supply flame roll out switch open STATUS CODE 34 IGNITION PROVING FAILURE Control will try three more times before lockout 14 occurs...

Page 19: ...rststageandsecondstagecoolingare satisfied the compressorwill shut off NOTE When two stage unit is operating at low stage system vapor suction pressure will be higher than a standard single stage syst...

Page 20: ...age Ther mal Cutout 72 Compressor voltage sensed then disappears while cooling or heat ing demand exists Possible causes are internal compressor over load trip or start relay not releasing if installe...

Page 21: ...nes what heating stage to run based on feedback from the UI If the UI is asking for low stage gas heat the ignition control will changetheinducerspeedtolow speedand keepthe gasvalve energized on low s...

Page 22: ...ate and clockwise in to increase input rate REGULATOR COVER SCREW PLASTIC ADJUST SCREW LOW STAGE GAS PRESSURE REGULATOR ADJUSTMENT MANIFOLD PRESSURE TAP INLET PRESSURE TAP ON OFF SWITCH REGULATOR SPRI...

Page 23: ...one revolution takes 84 sec and the heating value of the gas is 1050 Btu ft3 Proceed as follows a 84 sec to complete one revolution b 3600 84 42 9 c 42 9 x 2 85 8 ft3 of gas flow hr d 85 8 x 1050 90...

Page 24: ...oblem in the case of a gas component failure To initiate the component test procedure ensure that there arenoUIinputstothecontrol theABCDconnectorcan beremoved fromthe Infinitycontrol boardfor thisope...

Page 25: ...eading Indoor air CFM must be within the normal operating range of the unit TO USE COOLING CHARGING CHARTS Take the liquid line temperature and read the manifold pressure gauges Refer to the chart to...

Page 26: ...578 41 39 36 30 384 108 103 98 88 2647 42 40 37 31 394 110 105 100 90 2716 44 41 38 32 404 112 107 102 92 2785 45 42 39 33 414 114 109 104 94 2854 46 43 40 34 424 116 111 106 96 2923 47 44 41 35 434 1...

Page 27: ...nsional size and type as originally installed See Table 1 for recommended filter sizes Inspect air filter s at least once each month and replace throwaway type or clean cleanable type at least twice d...

Page 28: ...ly After inspecting the electrical controls and wiring replace all the panels Start the unit and observe at least one complete cooling cycle to ensure proper operation If discrepancies are observed in...

Page 29: ...performing any service that may risk exposure ofcompressor oil to the roof take appropriate precautions to protect roofing Procedures which risk oil leakage include but are not limited to compressor r...

Page 30: ...mand for compressor operation the contactor may be stuck closed or there is a wiring error The control will flash the appropriate fault code COMPRESSOR THERMAL CUTOUT If the control senses the compres...

Page 31: ...should fail low ambient cooling will not be allowed Defrost will occur at each time interval during heating operation but will terminate after 5 minutes If there is a thermistor out of range error de...

Page 32: ...h 520 psig low side retard S Use hoses with 750 psig service pressure rating S Leak detectors should be designed to detect HFC refrigerant S Puron as with other HFCs is only compatible with POE oils S...

Page 33: ...operates continuously Dirty air filter Replace filter Unit undersized for load Decrease load or increase unit size UI temperature set too low Reset UI setting Low refrigerant charge Locate leak repair...

Page 34: ...unit 2 Check gas valve Inducer pressure switch not closing 1 Check pressure switch wires connections and tubing Repair or replace if necessary Inadequate heating Dirty air filter Clean or replace fil...

Page 35: ...ESS III START UP ELECTRICAL SUPPLY VOLTAGE __________________________________ COMPRESSOR AMPS_________________________________ INDOOR EVAPORATOR FAN AMPS___________ TEMPERATURES OUTDOOR CONDENSER AIR...

Page 36: ...W Morris St S Indianapolis IN 46231 Manufacturer reserves the right to change at any time specifications and designs without notice and without obligations Catalog No 48DU 2SI Replaces 48DU 1SI Print...

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