Error Code PH: Low discharge superheat protection
Possible Cause
- EEV failed
- Poor heat exchange on the evaporating side
- Refrigerant overcharged
Troubleshooting
- If the T3/T5 sensor fails - Replace the sensor (chart below)
- Poor heat exchange on the evaporator coil - correct it
- If the EEV fails - replace it
Verify if refrigerant charge (overcharge) - adjust charge
T1 / T2 / T3 / T4 Sensor Temperature/Resistance Chart °F °C KΩ 0 -17.8 93.535 10 -12.2 67.795 20 -6.7 49.652 30 -1.1 36.710 40 4.4 27.386 50 10.0 20.610 60 15.6 15.648 70 21.1 11.987 80 26.7 9.265 90 32.2 7.225 100 37.8 5.683 110 43.3 4.509 120 48.9 3.606 130 54.4 2.902 140 60.0 2.350 150 65.6 1.914 160 71.1 1.574 170 76.7 1.276 T5 Sensor Temperature/Resistance Chart °F °C KΩ 0 -17.8 505.551 10 -12.2 362.739 20 -6.7 265.398 30 -1.1 195.601 40 4.4 146.695 50 10.0 110.707 60 15.6 84.465 70 21.1 65.408 80 26.7 50.904 90 32.2 40.152 100 37.8 31.807 110 43.3 25.506 120 48.9 20.529 130 54.4 16.708 140 60.0 13.643 150 65.6 11.214 160 71.1 9.308 170 76.7 7.746 180 82.2 6.504 190 87.8 5.474 200 93.3 4.645 210 98.9 3.949 220 104.4 3.383 230 110.0 2.904 240 115.6 2.503 250 121.1 2.172
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.