Lennox Elite XC13 Installation Instructions Manual page 23

START: Measure outdoor ambient temperature
USE EITHER APPROACH
OR SUBCOOLING
METHOD
WEIGH IN TXV
A
Liquid Line
Refrigerant
Charge per Line
Set Diameter
Set Length
3/8" (9.5 mm)
START: Measure outdoor ambient temperature
USE WEIGH-IN METHOD
DO NOT CHARGE UNIT
Weigh-in or remove refrigerant
(Results of charging at low
based upon line length
temperatures not reliable)
APPROACH TXV
B
If refrigerant is added
or removed, retest to
confirm that unit is
properly charged.
If value is greater than shown (high approach),
add refrigerant; if less than shown (liquid
temperature too close to ambient temperature,
low approach), remove refrigerant.
ABOVE or
65ºF
and
ABOVE
Once refrigerant charge is
correct, disconnect gauge set
and replace service port caps.
Ounces per 5 feet (g per 1.5 m)
adjust from 15 feet (4.6 m) line set*
3 ounce per 5' (85 g per 1.5 m)
Figure 35. Using HFC−410A Weigh In (TXV) Charge Method
ABOVE or
BELOW
64ºF and
BELOW
ºF (ºC)*
Any
*Temperature of air entering outdoor coil
Figure 36. Using HFC−410A Approach (TXV) Charge Method
64ºF and
BELOW
BELOW
1. Connect gauge set as illustrated in figure 32.
65ºF
2. Confirm proper airflow across coil using figure 33.
and
3. Compare unit pressures with table 4, Normal
ABOVE
Operating Pressures.
4. Set thermostat to call for heat (must have a cooling
load between 70-80ºF (21−26ºC).
5. When heat demand is satisfied, set thermostat to call
for cooling.
6. Allow temperatures and pressures to stabilize.
7. Record outdoor ambient temperature:
AMBº =_________
8. Record liquid line temperature:
LIQº = __________
9. Subtract to determine approach (APPº):
LIQº_____ − AMBº _____ = APPº_____
10. Compare results with table below.
APPº (Approach) Values(F:+/−1.0° [C: +/−0.6°])
−018 −024
4 (2.2) 8 (4.4) 8 (4.4)
Page 23
1. Connect gauge set as illustrated in figure
32.
2. Check Liquid and suction line pressures
3. Compare unit pressures with table 4,
Normal Operating Pressures.
4. Weigh in the unit nameplate charge plus
any charge required for line set differences
over feet.
This nameplate is for illustration
purposes only. Go to actual
nameplate on outdoor unit for
charge information.
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.
−030 −036 −042 −048
11 (6.1) 7 (3.9) 8 (4.4)
−060
9 (5.0)
XC13 SERIES