Lennox Merit Series 13ACX Installation Instructions Manual page 17

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.
START: Measure outdoor ambient temperature
USE WEIGH-IN METHOD DO NOT CHARGE UNIT
Weigh-in or remove refriger- (Results of charging at low
ant based upon line length temperatures not reliable)
If refrigerant is added
or removed, verify
charge using the
Subcooling Method.
If value is LESS
than shown, add
refrigerant.
ABOVE or
BELOW
65ºF
and
ABOVE
Figure 31. HFC−410A Weigh In TXV Method
ABOVE or
BELOW
64ºF and
BELOW
If value is MORE
than shown, remove
refrigerant.
MORE or
LESS
Figure 32. HFC−410A Approach TXV Charge
64ºF and
BELOW
1. Confirm proper airflow across coil using figure
65ºF
and
2. Compare unit pressures with Table 4, Normal
ABOVE
3. Set thermostat to call for heat (must have a
4. Connect gauge set.
5. When heat demand is satisfied, set thermostat
6. Allow temperatures and pressures to stabilize.
7. Record outdoor ambient temperature:
8. Record liquid line temperature:
9. Subtract to determine approach (APPº):
10. Compare results with table below.
APPº (Approach) Values(F:+/−1.0° [C: +/−0.6°])
ºF (ºC)* −018 −024
Any 4 (2.2) 8 (4.4) 8 (4.4)
*Temperature of air entering outdoor coil
Page 17
1. Check Liquid and suction line pressures
2. Compare unit pressures with Table 4,
Normal Operating Pressures.
3. Conduct leak check;
previously outlined.
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.
29.
Operating Pressures.
cooling load between 70-80ºF (21−26ºC).
to call for cooling.
AMBº =_________
LIQº = __________
LIQº_____ − AMBº _____ = APPº_____
−030 −036 −042 −048
11 (6.1) 9 (5.0) 8 (4.4)
evacuate as
−060
9 (5.0)
13ACX SERIES