Carrier 38VMA Series - Protection Control; High Pressure Protection Control; Low Pressure Protection Control; Discharge Pipe Protection Control

V. Protection Control
1. High Pressure Protection Control
This high pressure protection control is used to protect the compressor from abnormal increase of high pressure in the system.
When Pc > 566 psi, outdoor unit will stop and the error code “P1” is displayed
.
Figure 31 - Cooling Operation
INV INV1
Figure 32 - Heating Operation
2. Low Pressure Protection Control
When Pe < 7.25 psi, outdoor unit will stop and the error code “P2” is displayed .
3. Discharge Pipe Protection Control
This discharge pipe protection control is used to protect the compressor from abnormal increase of discharge temperature. When
the discharge temperature > 248⁰F, the outdoor unit will stop and the error code “P4” is displayed
.
NOTE:
Each compressor has its own discharge pipe temperature protection control and operates individually in the following sequence.
Figure 33 - Cooling Operation Figure 34 - Heating Operation
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