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506083−01 03/08
WHEN TO CHARGE?
Warm weather best
Can charge in colder weather
CHARGE METHOD? Determine by:
Metering device type
Outdoor ambient temperature
REQUIREMENTS:
Sufficient heat load in structure
Indoor temperature between 70-80ºF (21−26ºC)
Manifold gauge set connected to unit
Thermometers:
−
to measure outdoor ambient temperature
−
to measure liquid line temperature
−
to measure suction line temperature
APPROACH OR
SUBCOOLING
WEIGH-IN
64ºF (17.7ºC)
and BELOW
65ºF (18.3ºC)
and ABOVE
START: Determine how refrigerant is metered
TXV
Figure 28. Determining Charge Method
OUTDOOR AMBIENT
TEMPERATURE
START: Measure outdoor ambient temperature
64ºF and
BELOW
1. Check Liquid and suction line pressures
2. Compare unit pressures with Table 27,
Normal Operating Pressures
.
3. Conduct leak check; evacuate as
previously outlined.
4. Weigh in the unit nameplate charge plus
any charge required for line set differences
over feet.
Liquid Line
Set Diameter
Ounces per 5 feet (g per 1.5 m)
adjust from 15 feet (4.6 m) line set*
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.
Refrigerant Charge per Line Set Length
USE EITHER APPROACH
OR SUBCOOLING
METHOD
This nameplate is for illustration purposes
only. Go to actual nameplate on outdoor
unit for charge information.
ABOVE or
BELOW
WEIGH IN TXV
Figure 29. Weigh In Method
65ºF
and
ABOVE
