Fault codes covered
31-11, 31-58
This system contains a discharge pressure transducer to ensure compressor reliability. The high pressure limit is based on compressor model and varies with operating speed. When this fault occurs, the system will shut down and restart after 5 minute compressor protection time delay if demand is still present. Each time the fault occurs the maximum allowable compressor speed will be reduced by 25% until the minimum allowable compressor speed is reached. Each hour of compressor operation without fault re-occurrence will increase the compressor speed limit by 25%. This ensures that partial operation is still possible and system will self-correct if the issue causing fault is removed. Code 31-58 occurs when the compressor high pressure limit is reached while the compressor is at its minimum operating speed. System will “lock out” for 2 hours and attempt to resume normal operation afterwards. Multiple external factors may generate this fault: Dirty condenser, lack of airflow across condenser, condenser airflow recirculation, extreme high temperature and sun loading, refrigerant circuit blockage, faulty EXV/TXV, or overcharge.
Source: ACHPVSR454-02SM troubleshooting pages.