Bryant 607C024 Installation Instructions Manual Download Page 16

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Checking and Adjusting Refrigerant Charge

The refrigerant system is fully charged with Puron (R--410A)

refrigerant and is tested and factory sealed.

NOTE

Adjustment of the refrigerant charge is not required

unless the unit is suspected of not having the proper Puron
(R--410A) charge.
A subcooling charging chart is attached to the outside of the

service access panel. The chart includes the required liquid line
temperature at given discharge line pressures and outdoor ambient

temperatures.
An accurate thermocouple-- or thermistor--type thermometer, and a

gauge manifold are required when using the subcooling charging

method for evaluating the unit charge. Do not use mercury or small
dial--type thermometers because they are not adequate for this type

of measurement.

NOTE

: Allow system to operate for a minimum of 15 minutes

before checking or adjusting refrigerant charge.

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.
Proceed as follows:

1. Remove caps from low-- and high--pressure service fittings.
2. Using hoses with valve core depressors, attach low-- and

high--pressure gauge hoses to low-- and high--pressure

service fittings, respectively.

3. Start unit and let run until system pressures stabilize.
4. Measure and record the following:

a. Outdoor ambient--air temperature (

F [

C] db).

b. Liquid line temperature (

F [

C]) at TXV.

c. Discharge (high--side) pressure (psig).

d. Suction (low--side) pressure (psig) (for reference only).

5. Using Cooling Charging Charts compare outdoor--air

temperature (

F [

C] db) with the discharge line pressure

(psig) to determine desired system operating liquid line

temperature (See Fig. 19).

6. Compare actual liquid line temperature with desired liquid

line temperature. Using a tolerance of

F (

1.1

C), add

refrigerant if actual temperature is more than 2

F (1.1

higher than proper liquid line temperature, or remove

refrigerant if actual temperature is more than 2

F (1.1

lower than required liquid line temperature.

NOTE

If the problem causing the inaccurate readings is a

refrigerant leak, refer to Check for Refrigerant Leaks section.

Indoor Airflow and Airflow Adjustments

All 607C blower motors are factory wired for nominal cooling

airflow operation at minimum external static pressure. See Table 1.

NOTE

: Be sure that all supply-- and return--air grilles are open,

free from obstructions, and adjusted properly.

Table 3 – Color Coding for Indoor Fan Motor Leads

Black = High Speed

Orange = Med--High Speed

Red = Med Speed

Pink = Med--Low Speed

Blue = Low Speed

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal

injury or death.
Disconnect electrical power to the unit and install lockout

tag before changing blower speed.

WARNING

The fan speed of the unit is connected to the “HIGH” terminal on
the interface fan board (IFB) (See Fig. 12--14 and 17). The unit is

factory--shipped with a fan speed as noted in Table 4. There are 4

additional speed tap wires available for use (For color coding on
the indoor fan motor leads, see Table 4). The additional 4 speed tap

wires are shipped loose with vinyl caps and are located in the
control box, near the IFB.
To change the fan speed, remove the vinyl cap off of the desired
speed tap wire (Refer to Table 3 for color coding). Remove the

current speed tap wire from the “HIGH” terminal on the interface

fan board (IFB) (Fig. 17) and place vinyl cap over the connector on
the wire. Connect the desired speed tap wire to the “HIGH”

terminal on the IFB. For optimum performance, add the wet coil
pressure drop in Table 5 to the system static to determine the

correct cooling airflow speed in Table 4 that will deliver the

nominal cooling airflow as listed in Table 1 for each size.
NOTE: For cooling operation, the recommended airflow is 350 to

450 CFM for each 12,000 Btuh of rated cooling capacity.
NOTE: If accessory electric heat is installed in the unit, the dry

airflow must meet or exceed the minimum airflow specified in

Table 2 for the specific size. Use Table 4 to determine dry airflow
for a known external static pressure. Electric heat fan speed is the

same as cooling fan speed.

Continuous Fan Operation

The continuous fan operates at the same fan speed as cooling

operation.