set it to around 45-55% like luckyorange had said. 35% is gonna damage ur camera in certain areas, like drying up of the rubber parts of the camera and also cause the grease on the interior moving parts to dry up quicker.
I just bought a 38L last week and had been trying to calibrate it by fine tuning the control. But the RH always hang around 30% even on H, M or L settings...
Not sure is the analog reader not accurate or the unit faulty.
Please don't set your RH too low. I think 35% is abit low, but shouldn't be too much of a problem 45-55% is the best RH though. When you set your RH too low, it will damage the rubber in your lens and cam body.
As to the power cut off, it is okay. Because there simply is no use for the power to keep running until the RH had risen beyond certain level and pass the set value... it work pretty much like a thermostat, when the temperature had reach the preset level, power will be cut off. When temperature drop or raise beyond that level, power would resume.