Start−Up And Charging Procedures - Lennox TSA036H4N41 Installation Instructions Manual

Start−Up and Charging Procedures
IMPORTANT
If unit is equipped with a crankcase heater, it should
be energized 24 hours before unit start−up to
prevent compressor damage as a result of slugging.
1. Rotate fan to check for binding.
2. Inspect all factory− and field−installed wiring for loose
connections.
3. After evacuation is complete, open both the liquid and
suction line service valves to release the refrigerant
charge contained in the outdoor unit into the system.
4. Replace the stem caps and tighten to the value listed
in table 1.
5. Check voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit's
nameplate. If not, do not start the equipment until you
have consulted with the power company and the
voltage condition has been corrected.
Temp.
80 24 24 24 23 23 22 22 22 20 19 18 17 16 15
of air
entering
78 23 23 23 22 22 21 21 20 19 18 17 16 15 14
indoor
76 22 22 22 21 21 20 19 19 18 17 16 15 14 13
coil ºF
74 21 21 21 20 19 19 18 17 16 16 15 14 13 12
A 72 20 20 19 18 17 17 16 15 15 14 13 12 11 10
70 19 19 18 18 17 17 16 15 15 14 13 12 11 10
Wet−bulb ºF
57 58 59 60 61 62 63 64 65 66 67 68 69 70
T
Drop
C
19º
53º
air flow
DRY
BULB
All temperatures are
expressed in ºF
DT
B
A
72º
B
air flow
64º
DRY
BULB
INDOOR
WET
BULB
COIL
Figure 27. Checking Indoor Coil Airflow Guide
6. Set the thermostat for a cooling demand. Turn on
power to the indoor indoor unit and close the outdoor
unit disconnect switch to start the unit.
7. Recheck voltage while the unit is running. Power must
be within range shown on the nameplate.
8. Check system for sufficient refrigerate by using the
procedures listed under Testing and Charging
System.
SETTING UP TO CHECK CHARGE
1. Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of HFC−410A.
2. Connect the manifold gauge set to the unit's service
ports as illustrated in figure 1.
low pressure gauge to suction line service port.
D
high pressure gauge to liquid line service port.
D
INDOOR COIL AIRFLOW CHECK
Check indoor coil airflow using the Delta−T (
as illustration in figure 27.
DETERMINING CHARGE METHOD
To determine the correct charging method, use the
illustration in figure 27.
1. Determine the desired DT Measure entering air temperature
using dry bulb (A) and wet bulb (B). DT is the intersecting value of A
and B in the table (see triangle).
2. Find temperature drop across coil Measure the coil's dry bulb
entering and leaving air temperatures (A and C). Temperature Drop
Formula: (T ) = A minus C.
Drop
3. Determine if fan needs adjustment If the difference between
the measured T and the desired DT (T
Drop
adjustment is needed. See examples: Assume DT = 15 and A temp.
= 72º, these C temperatures would necessitate stated actions:
Cº T – DT
Drop
53º 19 – 15
58º 14 – 15
62º 10 – 15
4. Adjust the fan speed See indoor unit instructions to increase/
decrease fan speed.
Changing air flow affects all temperatures; recheck temperatures to
confirm that the temperature drop and DT are within +3º.
Page 15
–DT) is within +3º, no
Drop
ºF ACTION
=
4 Increase the airflow
=
−1 (within +3º range) no change
=
−5 Decrease the airflow
=
DT) process
TSA*H4 SERIES