EXPLOSION-PROOF DEVICE WITH UNGROUNDED VOLTAGE LIMITER Russian patent published in 2012 - IPC H02H9/04 

FIELD: electricity.

SUBSTANCE: invention has two body frames divided by power-limiting barrier. In the first body frame there are contacts (terminals) of leads supplying power and subject to sparking or ignition that is why this body frame is made explosion-proof. Power-limiting barrier provides limitation of power that can be delivered potentially to the second body frame up to the level when sparking (ignition) is impossible. It allows making the second body frame explosion-proof without performance of explosion safety requirements and producing all user interface elements (keys and indicators) in more economic way.

EFFECT: provision of compliance with explosion safety requirements.

39 cl, 4 dwg