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Page 44

KG/KC 024, 030, 036, 048, 060, 072, 074, 090

TABLE 12

KGA 060S -5 & HIGHER; KCA 060S -4 & HIGHER

NORMAL OPERATING PRESSURES

Outdoor Coil

Entering Air Temp

Discharge

+10 psig

S 5

psig

279

130

317

135

359

139

404

143

105

454

143

115

508

143

D-Charge Verification-Approach Method--Fin/Tube Coils
KGA/KCA 036-060 Units

1- Using the same thermometer, compare liquid

temperature to outdoor ambient temperature.

Approach Temperature = Liquid temperature minus
ambient temperature.

2- Approach temperature should match values in table

13. An approach temperature greater than value
shown indicates an undercharge. An approach
temperature less than value shown indicates an
overcharge.

3- Do not use the approach method if system pressures

do not match pressures in tables 7 through 12. The
approach method is not valid for grossly over or
undercharged systems.

TABLE 13

APPROACH TEMPERATURE

Unit

Liquid Temp. Minus Ambient Temp.

036S

7°F + 1 (3.9°C + 0.5)

048S

11°F + 1 (6.1°C + 0.5)

060S

6°F + 1 (3.3°C + 0.5)

E-Refrigerant Charge and Check - All-Aluminum Coil
KGA/KCA 072, 090 & KGB/KCB024-074

WARNING-Do not exceed nameplate charge under
any condition.

This unit is factory charged and should require no further
adjustment. If the system requires additional refrigerant,

reclaim the charge,

evacuate the system,

and

add

required nameplate charge.

NOTE - System charging is not recommended below
60

F (15

C). In temperatures below 60

F (15

C),

the

charge

must

be weighed into the system.

If weighing facilities are not available, or to check the
charge, use the following procedure:

IMPORTANT - Charge unit in standard cooling mode.

1- Make sure outdoor coil is clean. Attach gauge

manifolds and operate unit at full CFM in cooling mode
with economizer disabled until system stabilizes
(approximately five minutes). Make sure all outdoor air
dampers are closed.

2- Compare the normal operating pressures (see table

14 through 21) to the pressures obtained from the
gauges. Check unit components if there are
significant differences.

3- Measure the outdoor ambient temperature and the

suction pressure. Refer to the appropriate circuit
charging curve to determine a target liquid
temperature.

Note - Pressures are listed for sea level applications.

4- Use the same thermometer to accurately measure the

liquid temperature (in the outdoor section).

If measured liquid temperature is higher than

the target liquid temperature, add refrigerant to
the system.

If measured liquid temperature is lower than

the target liquid temperature, recover some
refrigerant from the system.

5- Add or remove charge in increments. Allow the

system to stabilize each time refrigerant is added or
removed.

6- Continue the process until measured liquid

temperature agrees with the target liquid
temperature. Do not go below the target liquid
temperature when adjusting charge. Note that
suction pressure can change as charge is adjusted.

7- Example KG/KC 090: At 95°F outdoor ambient and

a measured suction pressure of 130psig, the target
liquid temperature is 99°F. For a measured liquid
temperature of 106°F, add charge in increments
until measured liquid temperature agrees with the
target liquid temperature.

TABLE 14

KGB/KCB024 Normal Operating Pressures

Outdoor Coil Entering Air Temperature