57
Check Compressor Oil Level —
After adjusting the
refrigerant charge, allow each circuit to run fully loaded for
20 minutes. Stop the compressors and check the oil level. Oil
level should be
1
/
8
to
3
/
8
up on the sight glass.
Add oil only if necessary to bring the oil into view in the
sight glass. If oil is added, run the circuit for an additional
10 minutes, then stop and check oil level. If the level remains
low, check the piping system for proper design for oil return;
also, check the system for leaks. If checking the oil level with
unit running in part load, let unit run one hour, then run at full
load for 10 minutes. If oil does not return to acceptable sight
glass levels, check for correct suction piping and line sizing.
Adjust Oil Charge —
Although the compressors are
factory charged with oil, additional oil is likely required to
maintain the oil level in the compressor. Tables 12-15 indicate
the likely amount required based on the liquid line size and
system piping length. Additional lubricant estimate is based on
using recommended pipe sizes. Values listed are estimates
only. See Adding Oil section on page 147 for Carrier-approved
oils. After operating the compressor for a period of time, the
oil level should be between
1
/
8
and
3
/
8
of the oil sight glass.
The compressor oil level should be checked with the compres-
sor off to avoid the sump turbulence when the compressor is
running. Oil must be added if the oil level does not meet the
requirements.
Table 12 — 38AP 60 Hz Additional Lubricant (English)
IMPORTANT: Oil level should only be checked when the
compressors are off.
UNIT SIZE
CIRCUIT
ADDITIONAL LUBRICANT (FLUID OUNCES) ESTIMATE FOR PIPING LENGTH AND REFRIGERANT
UP to 25 ft
25 to 50 ft
50 to 75 ft
75 to 100 ft
100 to 125 ft
125 to 150 ft
150 to 175 ft
175 to 200 ft
38APD025
A
0
0
0
7
8
8
9
10
B
0
0
0
7
8
8
9
10
38APS025
Single
10
12
17
19
22
24
26
29
38APD027
A
0
0
6
7
8
9
9
10
B
0
0
6
7
8
9
9
10
38APS027
Single
11
16
18
20
23
25
27
29
38APD030
A
0
0
7
7
8
9
16
17
B
0
0
7
7
8
9
16
17
38APS030
Single
12
17
19
21
24
26
28
44
38APD040
A
9
11
12
18
20
23
25
27
B
0
9
10
12
19
21
23
26
38APS040
Single
23
30
33
37
40
57
63
69
38APD050
A
9
11
16
19
21
23
25
28
B
11
16
18
20
23
25
27
29
38APS050
Single
29
35
39
51
57
63
68
74
38APD060
A
11
16
18
21
23
25
28
30
B
12
17
19
21
24
26
28
44
38APS065
Single
33
44
50
56
61
67
73
102
38APD070
A
12
17
19
21
24
26
28
44
B
20
26
30
33
36
40
59
65
38APD080
A
12
17
19
21
24
26
28
44
B
28
34
38
50
56
62
67
73
38APD090
A
23
30
33
37
40
57
63
69
B
28
34
38
50
56
62
67
73
38APD100
A
29
35
39
51
57
63
68
74
B
28
34
38
50
56
62
67
73
38APD115
A
28
34
38
50
56
62
67
73
B
33
44
50
56
61
67
73
102
38APD130
A
28
34
38
50
56
62
67
73
B
43
54
60
65
71
94
103
112