Electronic Functions Abbreviations; Electronic Control Working Environment; Main Protection - Lennox MPA012S4S-1L Service Manual

Electronic Functions Abbreviations

T1 Indoor ambient temperature
T2 Coil temperature of indoor heat exchanger
T2B Coil temperature of indoor heat exchanger outlet. (located in outdoor unit)
T3 Pipe temperature of outdoor heat exchanger
T4 Outdoor ambient temperature
T5 Compressor discharge temperature

Electronic Control Working Environment

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

Main Protection

Three minutes delay at restart for compressor
One minute delay for the fi rst 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)
Lennox Mini-Split Service Manual / Page 252