Check For Refrigerant Leaks; Start- -Up Adjustments; Checking Cooling And Heating Control Operation; Checking And Adjusting Refrigerant Charge - Carrier Infinity 48XT A Series Installation Instructions Manual

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HEATING INPUT (BTU/HR)*
High Stage
Low Stage
40,000
26,000
60,000
39,000
90,000
58,500
115,000
75,000
130,000
84,500
*Cubic ft of natural gas per hour for gas pressures of .5 psig (14 in. wc) or less and a pressure drop of .5 in. wc (based on a .60 specific gravity gas). Ref: Table
6.2 (b) NFPA54/ANSI Z223.1 ---2006.
CONTINUOUS FAN MODE
When continuous fan operation is requested by the User Interface
indoor fan motor will operate at continuous blower airflow.
Continuous fan operation is programmable. See the User Interface
Owner's Manual for detailed instructions. Terminal EAC- -1 is
energized as long as the indoor fan motor is energized.
During a call for gas heat, the Infinity control will transition the
indoor fan motor to continuous blower airflow or gas heat airflow,
whichever is lowest. The indoor fan motor will remain ON until
the burners ignite, then shut OFF and remain OFF for the
blower- -ON delay allowing the heat exchangers to heat up more
quickly, then restarts at the end of the blower- -ON delay period.
The indoor fan motor will revert to continuous- -blower airflow
after the gas heating cycle is completed.
When the UI "calls for cooling", the indoor fan motor will switch
to operate at cooling airflow. When the call for cooling is satisfied,
the indoor fan motor will operate an additional 90 seconds at
cooling airflow before transitioning back to continuous- -blower
airflow.
When the call for continuous fan is removed, the indoor blower
will continue operating for an additional 5 seconds before shutting
down, if no other function requires blower motor operation.
COMPONENT TEST
The Infinity Furnace Board features a gas component test system to
help diagnose a system problem in the case of a gas component
failure. To initiate the component test procedure, ensure that there
are no UI inputs to the control (the ABCD connector can be
removed from the Infinity control board for this operation) and all
time delays have expired. Turn on setup switch SW1- -6.
NOTE: The component test feature will not operate if the control
is receiving any UI signals or until all time delays have expired.
The component test sequence is as follows:
1. The control turns the inducer motor ON and keeps it ON
through step 3.
2. After waiting 10 seconds, the control turns the igniter ON
for 15 seconds, then OFF.
3. The control then turns the indoor fan motor on for 15
seconds, then OFF.
4. After shutting the blower motor OFF, the control runs the
inducer for 10 seconds, then turns it OFF.
NOTE:
The EAC terminals are energized when the blower is
operating.
After the component test is completed, one or more status codes
(11, 25, or 41) will flash. See component test section or Status
Code Label for explanation of status codes.
NOTE:
To repeat component test, turn setup switch SW1- -6 to
OFF and then back ON.

Check for Refrigerant Leaks

Locate and repair refrigerant leaks and charge the unit as follows:
1. Use both high- - and low- -pressure ports to relieve system
pressure and reclaim remaining refrigerant.
2. Repair leak following accepted practices.
All manuals and user guides at all-guides.com
Table 6 – Heating Inputs
GAS SUPPLY PRESSURE (IN. WC)
NUMBER OF
NUMBER OF
ORIFICES
ORIFICES
Min
2
4.0
3
4.0
3
4.0
3
4.0
3
4.0
MANIFOLD PRESSURE (IN. WC)
Natural
Max
High Stage
13.0
13.0
13.0
13.0
13.0
NOTE: Install a filter drier whenever the system has been opened
for repair.
3. Check system for leaks using an approved method.
4. Evacuate refrigerant system and reclaim refrigerant if no
additional leaks are found.
5. Charge unit with Puron (R- -410A) refrigerant, using a
volumetric- -charging cylinder or accurate scale. Refer to
unit rating plate for required charge.

Start- -Up Adjustments

Complete the required procedures given in the Pre- -Start- -Up
section before starting the unit. Do not jumper any safety devices
when operating the unit. Do not operate the unit in cooling mode
when the outdoor temperature is below 40°F (4.4_C) (unless
low- -ambient operation is enabled in the UI). Do not rapid cycle
the compressor. Allow 5 min. between "on" cycles to prevent
compressor damage.
CHECKING
COOLING
OPERATION
See UI Installation Instructions for detailed system CHECKOUT.

CHECKING AND ADJUSTING REFRIGERANT CHARGE

The refrigerant system is fully charged with Puron (R- -410A)
refrigerant and is tested and factory sealed.
NOTE: Any adjustment to refrigerant charge must be done with
unit operating in HIGH stage.
NOTE:
Adjustment of the refrigerant charge is not required
unless the unit is suspected of not having the proper R- -410A
charge. The charging label and the tables shown refer to system
temperatures and pressures in cooling mode only. A refrigerant
charging label is attached to the outside of the unit. If charge level
is suspect in heat pump heating mode, reclaim all refrigerant and
charge to rating plate amount. (This information may be obtained
from the physical data table also.)
IMPORTANT:
When evaluating the refrigerant charge, an
indicated adjustment to the specified factory charge must always be
very minimal. If a substantial adjustment is indicated, an abnormal
condition exists somewhere in the cooling system, such as
insufficient airflow across either coil or both coils.

REFRIGERANT CHARGE

The amount of refrigerant charge is listed on the unit rating plate
and/or the physical data table. Refer to the Refrigeration Service
Techniques Manual, Refrigerants Section.

NO CHARGE

Check for leak. Use standard evacuating techniques. After
evacuating system, weigh in the specified amount of refrigerant
(refer to system rating plate).

LOW CHARGE COOLING

Use Cooling Charging Chart (Fig. 24). Vary refrigerant until the
conditions of the chart are met. Note that charging charts are
different from type normally used. Charts are based on charging
the units to correct subcooling for the various operating conditions.
Accurate pressure gauge and temperature sensing devices are
required. Connect the pressure gauge to the service port on the
suction line. Mount the temperature sensing device on the suction
27
Natural
Low Stage
3.2∼ 3.8
1.4 ∼ 2.0
3.2∼ 3.8
1.4 ∼ 2.0
3.2∼ 3.8
1.4 ∼ 2.0
3.2∼ 3.8
1.4 ∼ 2.0
3.2∼ 3.8
1.4 ∼ 2.0
AND
HEATING
CONTROL

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