DM16-01.01.11-01en   Service manual 
Multi DC inverter R410A. Outdoor unit    33 
10.5.9 Low outdoor ambient temperature protection 
When compressor is off, T4 is be lower than -35℃.for 10s, the AC will stop and display “LP”. 
When compressor is on, T4 is be lower than -40
℃.for 10s, the AC will stop and display “LP”. 
When T4 is no lower than -32
℃.for 10s, the unit will exit protection.