Page 27
XC17 SERIES
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 (
D
T)
process using the illustration in Figure 12.
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.
Figure 12. Checking Indoor Airflow over Evaporator Coil using Delta−T Chart
Downloaded from
Содержание Signature XC17
Страница 21: ...Page 21 XC17 SERIES Figure 7 Typical XC17 Wiring Downloaded from ManualsNet com search engine...
Страница 39: ...Page 39 XC17 SERIES Figure 19 High Pressure Switch Operation Downloaded from ManualsNet com search engine...
Страница 40: ...Page 40 506510 01 Figure 20 Low Pressure Switch Operation Downloaded from ManualsNet com search engine...