Carrier 38VF008H117010 - 1. Outdoor electric control box assembly instructions

Carrier service manual R410A DC Inverter Series
Troubleshooting 175
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.
Note:
1. The phenomenon of the high pressure side of the system is blocked
①
:
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
②
:
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
③
:
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.
P1:
High pressure protec
tion
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.
Check the system and
fixed up the error
The high pressure side of the system is
blocked
①
for squashed pipe, blocked
valve or closed stop valve
Make sure all valves are open,
check the system, and remove
the obstacle
Refrigerant is excess
②
Discharge part of the refrigerant. Add
some oil if it leaks during the discharge
System contains air or nitrogen
③
Discharge the entire refrigerant. Then
vacuum the system and refill the refrigerant.
Add oil to the system if it leaks.
Outdoor main control board
is damaged
Yes
No
No
No
No
Yes
Yes
Yes
Replace the outdoor
main control board