Some working conditions are very unforgiving for circuit breakers.
An ambient temperature higher than 104°F requires calibration. High ambient temperatures can alter the performance of the circuit breaker. Since most enclosures are about 104°F, this is the standard calibration for almost all indoor circuit breakers. Anything lower or higher than 104°F might require you to upward or downward calibrate.
Different circuit breakers fit different altitudes. For instance, in high altitudes above 6000 feet, the air is thinner and does not conduct heat away from the current-carrying components. This means that the circuit breaker has to be calibrated for voltage, carrying ability, and interrupting capacity.
Thinner air prevents the build-up of dielectric charge that is capable of withstanding the voltage levels. Also, altitude can de-rate the power generation equipment. Talk to a power generation expert before purchasing circuit breakers for high attitudes
Moisture and Corrosion
For humid conditions, there is a recommend moisture treatment to help resist fungus and mould - notorious for destroying systems. In environments with high humidity, space heaters are often used in the enclosures.
Corrosion affects the components of the circuit breakers and thus leading to faulty systems. If they have to be used in corrosive areas, specially manufactured ones that are corrosion resistant should be used.
High Shock Probability
Some workplaces tend to have high probabilities of electrical shocks. In this case, anti-shock devices should be installed to prevent any mishaps.
Anti-shock devices consist of inertia counterweights over the poles that hold the trip bar. This weight, however, should not interrupt the functionality of the thermal or magnetic trip units.