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TPA*H4 SERIES
TO LIQUID
LINE SERVICE
VALVE
TEMPERATURE
SENSOR
DIGITAL SCALE
REFRIGERANT TANK
TEMPERATURE SENSOR
(LIQUID LINE)
MANIFOLD GAUGE SET
A
Close manifold gauge set valves and connect the center hose to a cylinder of HFC−410A. Set for
liquid phase charging.
B
Connect the manifold gauge set’s low pressure side to the true suction port.
C
Connect the manifold gauge set’s high pressure side to the liquid line service port.
D
Position temperature sensor on liquid line near liquid line service port.
OUTDOOR UNIT
CHARGE IN
LIQUID PHASE
CONNECTIONS FOR TESTING AND CHARGING
GAUGE SET
A
C
D
LOW
HIGH
B
TRUE SUCTION PORT
CONNECTION
INSIDE OUTDOOR UNIT
LIQUID LINE
SERVICE
PORT
Figure 19. Manifold Gauge Set Setup and Connections
ADDING OR REMOVING REFRIGERANT
1. Determine the desired
D
T
Measure entering air temperature
using dry bulb (
A
) and wet bulb (
B
).
D
T
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
Drop
) =
A
minus
C
.
3. Determine if fan needs adjustment
If the difference between
the measured
T
Drop
and the desired
D
T
(T
Drop
–
D
T)
is 3º, no
adjustment is needed. See examples: Assume
D
T
= 15 and
A
temp.
= 72º, these
C
temperatures would necessitate stated actions:
Cº T
Drop
–
D
T
=
ºF
ACTION
53º
19
–
15
=
4
Increase the airflow
58º
14
–
15
=
−1
(3º range) no change
62º
10
–
15
=
−5
Decrease the airflow
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
D
T are 3º.
D
T
80
24 24 24 23 23 22 22 22 20 19 18 17 16 15
78
23 23 23 22 22 21 21 20 19 18 17 16 15 14
76
22 22 22 21 21 20 19 19 18 17 16 15 14 13
74
21 21 21 20 19 19 18 17 16 16 15 14 13 12
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
57 58 59 60 61 62 63 64 65 66 67 68 69 70
Temp.
of air
entering
indoor
coil ºF
INDOOR
COIL
DRY
BULB
DRY
BULB
WET
BULB
B
T
Drop
19º
A
Dry−bulb
Wet−bulb ºF
A
72º
B
64º
C
53º
air flow
air flow
All temperatures are
expressed in ºF
Figure 20. Checking Indoor Coil Airflow Guide
