The 209, E-Frame circuit breaker combines power switching with accurate, reliable circuit protection in a compact single or multipole unit. The unit is ideal for branch circuit applications such as EDP, air conditioners, panel boards and lighting controls.

Utilizing the hydraulic-magnetic principle, the 209 family adapts itself to local applications and environments. Temperature conditions, which affect fuses and other thermal devices, are not a concern. The magnetic /ampere turn principle minimizes nuisance tripping due to temperature variations.
Inrush currents, due to ferroresonant transformers, lamps and capacitive filters, are now becoming more significant. Recognizing the need for this type of protection, Airpax offers the unique inertial delay which is standard for all 50/60Hz time delay units, but may be deleted where inrush is not a problem. No extra cost or special order is required.
The 209 family of circuit breakers withstands high pulses without tripping or affecting normal delay curves. This performance, however, does not derate or sacrifice protection.