Carrier DHMVHAQ24XA3 - Low Pressure Protection (PC03)

:
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
37
DIAGNOSIS AND SOLUTION (CONT.)
Low pressure protection (PC03)
Troubleshooting
NOTE: For certain models, the outdoor PCB cannot be removed separately. In this case, the outdoor electric control box should be replaced as a
whole.
Error Code PC03
Malfunction decision conditions
The outdoor pressure switch cuts off the system because low pressure is lower than 0.13 MPa and the
LED displays the failure code.
Supposed causes
Connection wires
Outdoor PCB
Low Pressure protector
Refrigerant
Low pressure protection
Are the low pressure protector and
the main control board wired properly?
Method: Disconnect the plug.
Measure the resistance of the
low pressure protector. If the
protector is normal the value is 0.
Does a problem still exist?
Yes
Yes
Replace the outdoor main board.
Does a problem still exist?
No
No
Is the low pressure
protector broken?
Is the outdoor ambient
temperature too low?
No
Yes
No
Is the valve core of the high
pressure valve fully opened?
Is the indoor fan running
properly in the COOLING mode?
No
Yes
Yes
No
Check whether the refrigerant
system is functioning properly.
When the refrigerant level is insucient,
does the system function properly
after additional refrigerant is added?
No
Reconnect the low pressure protector and the
main control board.
Replace the low pressure protector.
p
ressure va
l
v
e
Open the valve core of the high
pressure valve.
Stop the unit.
Refer to the
&ĂŶ^ƉĞĞĚŝƐKƉĞƌĂƟŶŐKƵƚƐŝĚĞ
KĨEŽƌŵĂůZĂŶŐĞŵĂůĨƵŶĐƟŽŶ