Carrier PC 111 - Manual (Page 42)

42
Table 20 — Compressor Loading and Unloading Sequences
COOLING
STAGE
SIZE 034 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 038 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 28
3 ON OFF OFF OFF 6 42
4 ON ON ON ON 6 72
5 ON ON OFF ON 8 86
6 ON OFF OFF ON 10 100
ACCESS DOOR
PE VFD
EXHAUST
AIR
LARGE ECONOMIZER
HOOD LOCATION
AUXILIARY
CONTROL BOX
POWER EXHAUST
ACCESS DOOR
SMALL ECONOMIZER
HOOD LOCATION
Fig. 48 — Modulating Power Exhaust Return End Sheet Metal Skin Detail; 48FM and 50FM,FS Units