Lennox 13ACX Installation Instructions Manual page 18

START: Determine how refrigerant is metered
WHEN TO CHARGE?
S
Warm weather best
S
Can charge in colder weather
CHARGE METHOD? Determine by:
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Metering device type
S
Outdoor ambient temperature
REQUIREMENTS:
S
Sufficient heat load in structure
S
Indoor temperature between 70-80ºF
(21−26ºC)
S
Manifold gauge set connected to unit
S
Thermometers:
− to measure outdoor ambient
temperature
− to measure liquid line temperature
− to measure suction line
temperature
START: Measure outdoor ambient temperature
USE EITHER APPROACH
OR SUBCOOLING
METHOD
WEIGH IN TXV
Refrigerant Charge per Line Set Length
Ounces per 5 feet (g per 1.5 m)
Liquid Line
adjust from 15 feet (4.6 m) line set*
Set Diameter
3/8" (9.5 mm)
3 ounce per 5' (85 g per 1.5 m)
NOTE − *If line length is greater than 15 ft. (4.6 m), add this
amount. If line length is less than 15 ft. (4.6 m), subtract this
amount.
506374−01 03/10
TXV
65ºF
(18.3ºC) and
(17.7ºC) and
Above
APPROACH OR
WEIGH-IN
SUBCOOLING
Figure 11. Determining Charge Method
(17.7ºC) and
ABOVE or
BELOW
65ºF
(18.3ºC) and
Above
Figure 12. HFC−410A Weigh In TXV Method
Page 18
Which
metering
device?
64ºF
(4.4ºC) and
Above
Below
SUPERHEAT
1. Check Liquid and suction line pressures
64ºF
2. Compare unit pressures with Table 3,
Normal Operating Pressures.
Below
3. Conduct
previously outlined.
4. Weigh in the unit nameplate charge plus
any charge required for line set differences
over feet.
RFC
40ºF
39ºF
(3.8ºC) and
Below
WEIGH-IN
leak check; evacuate
This nameplate is for illustration
purposes only. Go to actual
nameplate on outdoor unit for
charge information.
as