Hydraulic/magnetic circuit breakers from the company do not rely on a change in temperature caused by increased current flow to activate the trip mechanism. As a result, ambient temperature and sympathetic heating are said to have virtually no effect. In addition, unlike fuses, the hydraulic/magnetic circuit breakers do not deteriorate over time. The breakers can be used in any application from -40°F to 140°F (-40°C to 60°C) and are said to eliminate the design constraints associated with thermal breakers and fuses. Circuit Breaker Industries, Inc.
E-T-A Circuit Breakers