Circuit interrupters with air trap regions in fluid reservoirs

A power distribution switchgear assembly, comprising:

• a solid insulation housing that defines a first external opening and a first cavity extending into the solid insulation housing from the first external opening;
• a disconnect having a moving contact in selective engagement with a stationary contact in the first cavity;
• a window secured to the solid insulation housing at the first external opening;
• and
• an insulating fluid disposed within the first cavity, and
• wherein the window and the solid insulation housing form a groove at a periphery of the window to form a trap region that is in fluid communication with the first cavity and is configured to trap air bubbles in the insulating fluid, wherein the trap region is disposed in a portion of the first cavity that is not visible through the window from an outside of the solid insulation housing.

A pole unit for power distribution, the pole unit comprising:

• a solid insulation housing that defines a first external opening and a first cavity extending into the solid insulation housing from the first external opening;
• a disconnect having a moving contact in selective engagement with a stationary contact in the first cavity;
• a window secured to the solid insulation housing at the first external opening;
• and
• an insulating fluid disposed within the first cavity;
• and
• a temperature compensation assembly configured to release from a fastened position in the pole unit and expel vaporized insulation fluid away from a viewing direction through the window in response to a fault in the disconnect.