Specifications And Operations - Lennox MCA Series Service Manual

17. Specifications and Operations
CN8 Indoor ambient temperature
CN9 Coil temperature of indoor heat exchanger
T3 Pipe temperature of outdoor heat exchanger
T4 Outdoor ambient temperature
T5 Compressor discharge temperature
Input voltage: 230V
Input power frequency: 60Hz
Indoor fan normal working amp. is less than 1A
Outdoor fan normal working amp is less than 1.5A
Four-way valve normal working amp is less than 1A
Three minutes delay at restart for compressor
One minute delay for the first time start-up and three minutes delay for others
Temperature protection of compressor discharge
When the compressor discharge is getting higher, the running frequency will be limited as below rules:
If 215.6°F (102°C) < T5 < 244.4°F (115°C), decrease the frequency to the lower level every two minutes until to F1.
If T5 < 244.4°F (115°C) for ten seconds, the compressor will stop and restart till T5 < 194°F (90°C)
If the indoor units cannot receive the feedback signal from the outdoor units for two minutes, the unit will stop and display failure.
High Condenser Col Temp
Protection
Running Rules
Table 7. Electronic Functions Abbreviations
Table 8. Electronic Control Working Environment
Table 9.
Table 10. Indoor/Outdoor Units Communication Protection
When T3>149°F (65°C) for three seconds, the compressor will stop while the indoor fan and outdoor fan will continue.
When T3<125.6°F (52°C), the protection will release and the compressor will restart after three minutes.
If the compressor frequency keeps lower than RET_OIL_FREQ1_ADD for RET_OIL_TIME1_ADD,the AC will rise the
frequency to RET_OIL_FREQ2_ADD for RET_OIL_TIME2_
Main Protection
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