Overload Control; Stopping Operation - Carrier 38VMA Series Service Manual

Status
Thermal ON
OFF
Thermal OFF
Defrost starting condition:
Table 27 - Restart Standby
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)
Ending conditions

3. Overload Control

To maintain the required set point, the air flow of all indoor units are set to low speed if the connected capacity of the indoor
units is more than 120%. However, the air flow of the indoor units will return to normal once the connected capacity of
indoor unit is less than 105%.

4. Stopping Operation

Table 28 - When System is in Stop Mode
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)
Ending conditions
Stop operation of follower units while header unit is still in operation in a modular system.
Indoor unit Operation
Defrost operation is started when the outdoor heat exchanger temperature becomes lower than
threshold temperature. Defrost operation is conducted once in a maximum of 2 hours.
Component
Fan
OFF
OFF
OFF
Cooling Operation
OFF
OFF
OFF
OFF
350P
350P
0P
OFF
OFF
12 minutes
Cooling oil return operation
Electronic Expansion Valve
480P
480P
480P
Heating Operation
OFF
OFF
OFF
Holds
Initial pulse step
Initial pulse step
0P
OFF
OFF
12 minutes
Operation
OFF
OFF
OFF
OFF
350P
350P
0P
OFF
OFF
Indoor unit thermostat is turned ON
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