Carrier PC 111 User Manual
Page 43
43
Table 20 — Compressor Loading and Unloading Sequences (cont)
COOLING
STAGE
SIZE 044 UNITS
Lead Circuit
Lag Circuit
Active
Cylinders
Percent
Capacity
Comp 1
Unloader
U1
Comp 2
0
OFF
OFF
OFF
0
0
1
ON
ON
OFF
2
25
2
ON
OFF
OFF
4
50
3
ON
ON
ON
6
75
4
ON
OFF
ON
8
100
COOLING
STAGE
SIZE 048 UNITS
Lead Circuit
Lag Circuit
Active
Cylinders
Percent
Capacity
Comp 1
Unloader
U1
Unloader
U2
Comp 2
0
OFF
OFF
OFF
OFF
0
0
1
ON
ON
ON
OFF
2
19
2
ON
ON
OFF
OFF
4
38
3
ON
OFF
OFF
OFF
6
58
4
ON
ON
ON
ON
6
62
5
ON
ON
OFF
ON
8
81
6
ON
OFF
OFF
ON
10
100
COOLING
STAGE
SIZE 054 UNITS
Lead Circuit
Lag Circuit
Active
Cylinders
Percent
Capacity
Comp 1
Unloader
U1
Unloader
U2
Comp 2
0
OFF
OFF
OFF
OFF
0
0
1
ON
ON
ON
OFF
2
20
2
ON
ON
OFF
OFF
4
40
3
ON
OFF
OFF
OFF
6
60
4
ON
ON
OFF
ON
10
80
5
ON
OFF
OFF
ON
12
100
COOLING
STAGE
SIZE 064 UNITS
Lead Circuit
Lag Circuit
Active
Cylinders
Percent
Capacity
Comp 1
Unloader
U1
Unloader
U2
Comp 2
0
OFF
OFF
OFF
OFF
0
0
1
ON
ON
ON
OFF
2
17
2
ON
ON
OFF
OFF
4
33
3
ON
OFF
OFF
OFF
6
50
4
ON
ON
ON
ON
8
67
5
ON
ON
OFF
ON
10
83
6
ON
OFF
OFF
ON
12
100
COOLING
STAGE
SIZE 074, 078 UNITS
Lead Circuit
Lag Circuit
Active
Cylinders
Percent
Capacity
Comp 1
Unloader
U1
Unloader
U2
Comp 2
0
OFF
OFF
OFF
OFF
0
0
1
ON
ON
ON
OFF
2
14
2
ON
ON
OFF
OFF
4
29
3
ON
OFF
OFF
OFF
6
43
4
ON
ON
ON
ON
8
71
5
ON
ON
OFF
ON
10
86
6
ON
OFF
OFF
ON
12
100