Could anybody advise the manufacturer of enclosed safety or disconnect switch (pad-lockable, 30A, 3 phase, 480V) capable of operating at ambient temp. of -40 deg.Celcius? This is INDOOR application for climatic test chamber.
Can't you find a suitable switch designed and qualified for OUTSIDE application? -40 is a not-uncommon winter temperature in many places. I think all you need is an OUTDOOR switch with all the other parameters.
Excuse me if I'm reading too much into your capitalization of the word INDOOR.
Yes, I could use outdoor switch. I just wanted to say that I might not need all degrees of protection associated with outdoor design. The problem is that so far we found switches for -30 deg.C only and not for -40.