BTW, guys, I kinda solved my problem with one very hot blade..

My miner status:

Chain#   ASIC#   Frequency   MH/S(RT)   HW   Temp(PCB)   Temp(Chip)   ASIC status
1                 60            400                4934.56           0       63                        73
2                 60            300                3716.81           0       52                        81
3                 60            400                4925.63           0       63                        74


So, after HOURS operation with this status I have off miner, open it and check the temperature of heat sinks: CHAIN 2 was much COLDER than other two.
Hence, there is just bad thermopair in the second blade which overestimate chip temperature ~+20C.
Configuring my blades now checking only PCB temperature.