CHECKING REFRIGERANT CHARGE
Servicing of the refrigeration circuit must only be performed
by agencies or individuals possessing Type II or Universal
certification as defined in Section 608 of the Clean Air Act. See
Qualifications on page 6.
This HPWH unit is factory charged with 134a refrigerant. See the
rating label on the HPWH unit and Table 9 for refrigerant charge
by weight. It should not be necessary to add or remove refrigerant
during installation or start up. Refrigerant lost during frequent
refrigerant pressure testing can cause low refrigerant conditions.
Air and water flow should always be checked first to eliminate
other potential problems before checking the refrigerant charge.
Check Air Flow
Ensure the air filters are clean. Ensure the evaporator coil is
clean. Ensure the blower motor belt is not worn or loose. See
Figure 1 on page 8 for component locations. Correct any
problems with air flow before checking the refrigerant pressures.
Check Water Temperature Rise
Always check water temperature rise through the HPWH unit’s
internal heat exchanger before checking the refrigerant charge.
See Start Up on page 23 for information on how to measure
the water temperature rise.
If the measured water temperature rise during start up was within
8°F to 12°F (4°C to 7°C) checking the charge is not necessary
unless other conditions warrant testing.
If the measured temperature rise through the HPWH unit is less
than 8°F (4°C) checking the charge is not necessary unless other
conditions warrant testing. Short water piping runs between the
HPWH and the storage tank will produce lower temperature rises
and are not problematic.
If the measured temperature rise through the HPWH unit is more
than 12°F (7°C) check for restrictions in the inlet and outlet water
piping connected between the HPWH unit and the storage tank.
On new installations ensure the maximum equivalent feet of inlet
and outlet piping was not exceeded. This is the most common
cause of excessive water temperature rise on new installations.
See number 11 on page 22.
SUBCOOLING CALCULATION
1. Measure and record the liquid pressure at the liquid line
pressure test port inside the unit.
2. Convert the recorded liquid line pressure to saturated
3. Measure the liquid line temperature near the liquid line
pressure test port inside the unit.
4. Compare the liquid line temperature to the saturated
5. The difference between saturated temperature and liquid
line temperature is the subcooling.
Subcooling normal range
should be 5°F to 15°F (2.8°C to 8.5°C).
SUPERHEAT CALCULATION
1. Measure and record the suction pressure at the suction line
pressure test port inside the unit.
2. Convert the recorded suction pressure to saturated
temperature.
3.
Measure the suction line temperature near the suction line
pressure test port inside the unit.
4. Compare the suction line temperature to the to the saturated
TABLE 10
R134A SATURATED TEMPERATURE CHART
SATURATED
TEMPERATURE °F
SATURATED
TEMPERATURE °C
REFRIGERANT
PRESSURE (PSI)
0
-18
7
5
-15
9
10
-12
12
15
-9
15
20
-7
18
25
-4
22
30
-1
26
35
2
30
40
4
35
45
7
40
50
10
45
55
13
51
60
16
57
65
18
64
70
21
71
75
24
79
80
27
87
85
29
95
90
32
104
95
35
114
100
38
124
105
41
135
110
43
146
115
46
158
120
49
171
125
52
185
130
54
199
135
57
214
140
60
229
145
63
246
150
66
263
155
68
281
28
5. The difference between saturated temperature and sucti
o
n
line temperature is the superheat
. Superheat normal range
should be 8°F to 12°F (4.4°C to 6.7°C).
TABLE 9
MODEL
FACTORY CHARGE R134A
AWH-35
2lbs, 15oz
AWH-55
3lbs, 12oz
AWH-75
6lbs, 5oz
AWH-100
7lbs, 3oz
AWH-115
7lbs, 14oz
AWH-140
10lbs, 15oz
AWH-170
13lbs, 5oz
Summary of Contents for AWH-35
Page 2: ......
Page 32: ...UNIT WIRING DIAGRAMS FUSE SIZES 208 230 VAC SINGLE PHASE 60 HZ 32...
Page 33: ...UNIT WIRING DIAGRAMS FUSE SIZES 208 230 VAC THREE PHASE 60 HZ AWH 35 AWH 55 and AWH 75 only 33...
Page 34: ...UNIT WIRING DIAGRAMS FUSE SIZES 208 230 VAC THREE PHASE 60 HZ only 34...
Page 35: ...UNIT WIRING DIAGRAMS FUSE SIZES 460 VAC THREE PHASE 60 HZ 35...
Page 36: ...UNIT WIRING DIAGRAMS FUSE SIZES 460 VAC THREE PHASE 60 HZ only 36...
