What effect does length of time in service, ambient temperature, humidity, environmental particulates and gases, etc. have on breaker performance?
All MCCB and ICB
Resolution: Circuit breaker trip curves are not prone to permanent change due to any of these external factors. Thermal-magnetic breakers will have shorter overload trip times in elevated ambient temperatures and longer trip times in cold ambients because the bimetal responds to heat and doesn't care where it comes from.
Corrosive gasses can attack all metal parts and PCB's and humid environments may accelerate corrosion of metal parts. Grease may stiffen in extreme cold and may dry out if exposed to excessive heat for long periods of time, compromising free movement of the breaker's mechanical parts. Dusty conditions and condensing humidity have the potential of reducing dielectric strength of insulating material. Periodic testing of the breaker is recommended to ensure optimal performance. Please see attached.