Guaranteed working temperatures for SM6 are between -5°C to +40°C and -40°C to +70°C for stocking.
The higher limit (+40°C) is given by a temperature-rise limit. The standard allows a maximum temperature-rise with
an ambient temperature of 40°C. Above 40°C ambient temperature, we have to DECREASE the current.
The lower limit (-5°C) is given by mechanism. Under this limit, opening and closing time vary.
Below this value, opening and closing time change, so we can't guaranty SM6 under -5°C particularly with tripping parts.
There is a particularity with the CIT mechanism (the most simple, without tripping) that can be used up to -15°C.
At lower temperatures, the mechanism will have difficulty in functioning properly due to ice formation.