VAPOR VAPOR
TEMP. PRESS. TEMP. PRESS.
(DEG F) (PSIG) DEG F) (PSIG)
-20
17
70
146
-18
18
72
150
-16
20
74
155
-14
21
76
161
-12
23
78
166
-10
24
80
171
-8
26
82
177
-6
28
84
182
-4
29
86
188
-2
31
88
194
0
33
90
200
2
35
92
206
4
37
94
212
6
39
96
219
8
41
98
225
10
43
100
232
12
46
102
239
14
48
104
246
16
50
106
253
18
53
108
260
20
55
110
268
22
58
112
275
24
60
114
283
26
63
116
291
28
66
118
299
30
69
120
307
32
72
122
316
34
75
124
324
36
78
126
333
38
81
128
342
40
85
130
351
42
88
132
360
44
91
134
370
Pressure-Temperature Chart for HP62
This ice machine uses R-404A (HP62) refrigerant and polyolester oil. Do
NOT use mineral oil in this refrigeration system.
••
R-404A is a "Near Azeotrope" so liquid charging is required:
••
When the system is serviced, a special liquid line drier is required. It is
included with replacement compressors.
••
HP62 is not compatible with mineral oil, so these ice machines use
Polyolester oil. Polyolester oil absorbs water very easily. When one of
these refrigeration systems is opened for service, it must be re-sealed
as soon as possible (15 minutes maximum).
••
Special leak detection equipment is required to locate small refrigerant
leaks. Usually a leak detector capable of detecting a Halongenated
refrigerant or HFC-134a will work. Check with the leak detector
manufacturer if in doubt.
LIQUID CHARGING Instructions for R-404A
In preparation for charging, the low side hose should have a sight glass,
and/or a restrictor device (such as a "Charge Faster") installed in it for
metering liquid into the low side of the system.
1. After a thorough evacuation to at least 200 microns, shut off the
manifold valves and switch off the vacuum pump.
2. Place a drum of R-404A onto an electronic scale.
3. Attach the charging hose to the drum.
4. Open the valve on the drum and purge the charging hose.
5. Zero out the scale.
6. Shut the low side access valve at the ice machine.
7. Open the discharge manifold valve full open.
8. Watch the scale, when the correct charge is shown, shut the manifold
valve.
Note: If all of the charge will not "go in" the discharge side:
A. Shut the discharge access valve at the ice machine.
B. Switch the machine on.
C. Open the low side access valve at the ice machine.
D. Open the low side manifold valve and observe the sight glass to be
certain that only gas is flowing into the system.
E. When the proper charge is indicated on the scale, shut off the
manifold valve(s).
9. Shut off the valve on the refrigerant drum.
10. Re-open the manifold valves until all liquid has flowed out of the
hoses.
11. Shut the low side access valve on the ice machine.
12. Remove hoses from ice machine and replace all caps.
Removal and Replacement: Refrigeration System
SLE300
January 1995
Page 24
