Basic Control; Normal Operation; Capacity Calculation - Carrier 38VMA Series Service Manual

2. Basic Control

Table 4 - Cooling Operation
a. Normal Operation
Component
Compressor
Outdoor unit fan (FAN A)
Outdoor unit fan (FAN B)
Four way valve (ST1)
Electronic expansion valve (EXV A)
Electronic expansion valve (EXV B)
Electronic expansion valve (EXV C)
Solenoid valve (SV4)
Table 5 - Heating Operation
Solenoid valve (SV7)
Component
Compressor
Outdoor unit fan (FAN A)
Outdoor unit fan (FAN B)
Four way valve (ST1)
Electronic expansion valve (EXV A)
Electronic expansion valve (EXV B)
Electronic expansion valve (EXV C)
Solenoid valve (SV4)
Solenoid valve (SV7)
NOTE: Heating operation is not functional at an outdoor air temperature of 77°F or more.
Table 6 - Cooling Calculation
b. Capacity Calculation
Indoor Unit
Capacity (BTU) Capacity x 100W
6000
7000
9000
12000
13000
15000
18000
21000
24000
27000
30000
33000
Operation
Cooling Compressor control
Cooling fan control
Cooling fan control
OFF
350P
350P
PI control
17 minutes OFF，3 minutes ON
Pc ≥ 536.6 psi ON，Pc < 478.6 psi OFF
Operation
Heating Compressor control
Heating fan control
Heating fan control
ON
Heating EXV control
Heating EXV control
0P
17 min OFF，3min ON
Pc ≥ 507.6 psi ON，Pc < 420.6 psi OFF
Indoor Unit Indoor Unit
Capacity (HP) A
15, 17
22, 25
28
32, 36
40
45, 50
56
63
71
80
90
100
Used for high pressure protection control, discharge pipe
temperature protection control, and compressor operating
frequency upper limit control with inverter protection control.
Used for high pressure protection control, low pressure
protection control, discharge pipe temperature protection
control, and compressor operating frequency upper limit
control with inverter protection control.
Indoor Unit Capacity
(BTU)
0.5 36000
0.8 42000
1.0 48000
1.2 54000
1.4 60000
1.7 66000
2.0 72000
2.2 96000
2.5 120000
3.0 144000
3.2 168000
3.6 192000
Remarks
Remarks
Indoor Unit Capacity Indoor Unit Capacity
x 100W
112
125
140
160
180
200
224, 252
280
335
400
450
560, 580
(HP) A
4.0
4.5
5.0
6.0
6.5
7.0
8.0
10.0
12.0
14.0
16.0
20.0
22