Lennox TSA042H4N4 Installation Instructions Manual page 17

START: Measure outdoor ambient temperature
USE WEIGH‐IN METHOD
Weigh‐in or remove refriger­
ant based upon line length
If refrigerant is added
or removed, verify
charge using the
Subcooling Method.
If value is LESS
than shown, add
refrigerant.
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)
BLOCK OUTDOOR COIL: [sometimes necessary with lower
temperatures] Use cardboard or plastic sheet to restrict the airflow
through the outdoor coil to achieve pressures from 325-375 psig
(2240-2585 kPa). Higher pressures are needed to check charge.
Block equal sections of air intake panels and move coverings
sideways until the liquid pressure is in the above noted ranges.
If refrigerant is added
or removed, verify
charge using
Approach Method.
If value is LESS
than shown, add
refrigerant.
ABOVE or
BELOW
64ºF and
BELOW
If value is MORE
than shown, remove
refrigerant.
APPº (Approach) Values(F:+/-1.0° [C: +/-0.6°])
MORE or
ºF (ºC)*
LESS
Any
*Temperature of air entering outdoor coil
Figure 16. HFC-410A Approach TXV Charge
ABOVE or
BELOW
64ºF and
BELOW
If value is MORE
than shown, remove
the
refrigerant.
MORE or
LESS
Figure 17. HFC-410A Subcooling TXV Charge
1. Confirm proper airflow across coil using figure 14.
2. Compare unit pressures with Table 3, Normal Operating Pressures.
3. Set thermostat to call for heat (must have a cooling load between
70‐80ºF (21-26ºC).
4. Connect gauge set.
5. When heat demand is satisfied, set thermostat to call for cooling.
65ºF and
6. Allow temperatures and pressures to stabilize.
ABOVE
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.
-036 -042 -048
11 (6.1) 9 (5.0) 8 (4.4) 9 (5.0)
1. Confirm proper airflow across coil using figure
65ºF
and
2. Compare unit pressures with Table 3, Normal
ABOVE
3. Set thermostat to call for heat (must have a
4. Connect gauge set
5. Measure outdoor ambient temperature
6. When heat demand is satisfied, set thermostat to
7. Allow temperatures and pressures to stabilize.
8. Record liquid line temperature:
9. Measure liquid line pressure and use the value to
10. Subtract to determine subcooling (SCº):
11. Compare results with table below.
SCº (Subcooling) Values (F:+/-1.0° [C: +/-0.6°])
ºF (ºC)* -036
Any 12 (6.7)
*Temperature of air entering outdoor coil
Page 17
-060
14.
Operating Pressures.
cooling load between 70‐80ºF (21-26ºC)
call for cooling
NOTE - If necessary, block outdoor coil to
maintain 325 - 375 psig.
LIQº = ______
determine saturation temperature (see table 4):
SATº = ______
SATº_____ - LIQº _____ = SCº _____
-042 -048 -060
9 (5.0) 9 (5.0) 7 (3.9)
TSA*H4 SERIES