Abstract: A transfer switch for switching between power sources for a load includes a plurality of symmetrical phase plates, a plurality of stationary contact pads associated with each said phase plate, each stationary contact pad associated with a power source, a movable contact assembly associated with each phase plate, and a shaft connecting the phase plates and upon which each movable contact assembly is mounted for movement between stationary contact pads associated with each phase plate. The above transfer switch allows for two, three and four-pole modular configuration with minimal additional hardware.

Abstract: There is disclosed an electric heating unit having a housing with air circulation apertures, a heating element, and a passive heat storage member adjacent the heating element. The heat storage member is preferably a sealed chamber containing a heat storage material such as silica or oil. Heat transfer fins surround both the heating element and the heat storage member to facilitate heat transfer to the atmosphere. The heat transfer fins engage the heating element and the heat storage member with gripping collars which may be loosely fitted for installation, and a portion of the collars frictionally engaged with the respective element and storage member to secure the fins into an aligned position. The heat storage member continues to disburse heat to the surrounding atmosphere while the heating element is de-energized, thereby providing a uniform heating source to the room such that fewer energizing and de-energizing cycles of the heating element are required.