Unit Operates Long Or Continuously In Cooling; Unit Will Not Heat Or Heating Insufficient; Defrost Malfunction; Abnormal Pressure - Carrier Neos 100S Operation & Service Manual

INDICATION / TROUBLE
6.2.3

Unit Operates Long or Continuously in Cooling

Box
Refrigeration system
Compressor
6.2.4

Unit Will Not Heat or Heating Insufficient

Refrigeration
Compressor
6.2.5

Defrost Malfunction

Automatic defrost will not
initiate
Manual defrost will not initiate
Defrost cycle initiates but does
not defrost
Frequent defrost
Does not terminate or cycles on
defrost
6.2.6

Abnormal Pressure

Cooling:
High discharge pressure
Low discharge pressure
High suction pressure
Table 6–2 Mechanical Indications
POSSIBLE CAUSES
Hot Load
Defective box insulation or air leak
Abnormal pressure
Temperature controller malfunction
Defective
Abnormal pressure
Temperature controller malfunction
Hot gas solenoid malfunction
Compressor drive (clutch) defective
Compressor defective
Defrost thermostat (DTT) open or defective
Hot gas solenoid valve malfunction
Defrost disabled through cab command
Microprocessor defective
Defrost thermostat (DTT) open or defective
Hot gas solenoid malfunction
Condenser Pressure Control valve malfunction
Wet load
Defrost settings set too low.
Defrost thermostats (DTT) shorted closed
Condenser coil dirty
Non-condensables in system
Refrigerant overcharge
Condenser fan/motor defective
Compressor defective
Hot gas solenoid malfunction
Low refrigerant charge
Compressor defective
Hot gas solenoid malfunction
Compressor pressure regulator mis-adjusted (CPR)
6-3
REFERENCE
SECTION
Insufficient pull
down time
Correct
6.2.6
6.2.8
Replace
6.2.6
6.2.8
5.10
Check
Replace
Replace
5.10
3.6
Replace
Replace
5.10
5.10
--
3.6
Replace
5.16
5.7
5.6.1
Replace motor
Replace
5.10
5.6.1
Replace
5.10
5.11
62-11848