508219-01
Issue 2132
Page 39 of 43
Adding or Removing Refrigerant
This system uses HFC-410A refrigerant which operates at much higher pressures than HCFC-22. The pre-installed liquid
line filter drier is approved for use with HFC-410A only. Do not replace it with components designed for use with HCFC-22.
This unit is NOT approved for use with coils which use capillary tubes or fixed orifices as a refrigerant metering device.
Check airflow using the Delta-T (DT) process shown below..
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
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
Temperature 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
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 example below:
4.
Adjust the fan speed
— See indoor unit instructions to increase/decrease fan speed.
Assume
D
T
= 15 and
A
temp. = 72º, these
C
temperatures would necessitate stated actions:
AIRFLOW
Use the following procedure to adjust for optimal air flow across the indoor coil:
INDOOR COIL
Changing air flow affects all temperatures; recheck
temperatures to confirm that the temperature drop
and
D
T are 3º.
Summary of Contents for 4SCU14LB
Page 34: ...508219 01 Issue 2132 Page 34 of 43 Wiring Diagram Figure 13 A C Single Phase Wiring Diagram ...
Page 35: ...508219 01 Issue 2132 Page 35 of 43 Figure 14 A C Single Phase Wiring Diagram 59 model only ...
Page 36: ...508219 01 Issue 2132 Page 36 of 43 Figure 15 3 Phase 208 230 Volt ...
Page 37: ...508219 01 Issue 2132 Page 37 of 43 Figure 16 3 Phase 460 Volt ...
Page 41: ...508219 01 Issue 2132 Page 41 of 43 Charge Labels Figure 17 4SCU16LE 4SCU14LB 50 ...
Page 42: ...508219 01 Issue 2132 Page 42 of 43 Figure 18 4SCU14LE LB 4 thru 7 ...
