They are consuming about 1850 Watt and not 1650 Watt.
Also they are only running on about 1.4 - 1.5 Th/s and not 2 Th/s :/
Have you tried overclocking them, or is that not possible with these miners?
its not possible atm. I will try to contact the cointerra support. i hope they have an idea

maybe a new firmware or something like that