Carrier X-POWER Series Service Manual page 157

Carrier service manual
4.11 P1: High pressure protection (Display on faulty unit, all the ODU in standby)
When the pressure is over 4.4MPa, the system will display P1 protection, all the ODU in standby. When the pressure is lower
than 3.2MPa, P1 disappears and normal operation resumes.
P1: High pressure protection
The heat exchange of condenser
is not good. It may be caused by
dirty heat changer, abnormal ODU
fan running, ODU are too near to
each other, etc.
No
The high pressure side of the system is
①
blocked
valve or closed stop valve
No
Refrigerant is excess
No
System contains air or nitrogen
No
Outdoor main control board
is damaged
Note:
1. The phenomenon of the high pressure side of the system is blocked
The high pressure is higher than normal value, the low pressure is lower than normal value, and the discharge temperature is
higher than normal value.
2. The phenomenon of the refrigerant is excess
The high pressure is higher than normal value, the low pressure is higher than normal value, and the discharge temperature is
lower than normal value.
3. The phenomenon of the system contains air or nitrogen
The high pressure is higher than normal value, current is larger than normal value, discharge temperature is higher than
normal value, compressor makes noise, pressure meter do not display steady.
*The normal system running parameters please refer to attached table 3.
*If the system install three-phase protector, and the three-phase protector connect with high pressure switch in series
connection, the system will display P1 protection when fist power on, and P1 protection will disappear after system is steady.
*If the system install three-phase protector, and the three-phase protector connect with low pressure switch in series
connection, the system will display P2 protection when fist power on, and P2 protection will disappear after system is steady.
Troubleshooting
for squashed pipe, blocked
②
③
②
:
Yes
Check the system and
fixed up the error
Make sure all valves are open,
Yes
check the system, and remove
the obstacle
Yes
Discharge part of the refrigerant. Add
some oil if it leaks during the discharge
Discharge the entire refrigerant. Then
Yes
vacuum the system and refill the refrigerant.
Add oil to the system if it leaks.
Replace the outdoor
main control board
①
:
③
:
R410A DC Inverter Series
175